23rd February 2017
NASA discovers an entire solar system of seven Earth-sized planets
NASA astronomers have announced the discovery of seven Earth-sized exoplanets orbiting TRAPPIST-1, a dwarf star 39 light years from Earth – all of which may have the potential to support liquid water.
NASA's Spitzer Space Telescope has revealed the first known system of seven Earth-size planets around a single star. Three of these planets are firmly located in the habitable zone, the area around the parent star where a rocky planet is most likely to have liquid water.
The discovery sets a new record for greatest number of habitable-zone planets found around a single star outside our solar system. All of these seven planets could have liquid water – key to life as we know it – under the right atmospheric conditions, but the chances are highest with the three in the habitable zone.
"This discovery could be a significant piece in the puzzle of finding habitable environments, places that are conducive to life," said Thomas Zurbuchen, associate administrator of the agency's Science Mission Directorate in Washington. "Answering the question 'are we alone' is a top science priority and finding so many planets like these for the first time in the habitable zone is a remarkable step forward toward that goal."
Credit: ESO/O. Furtak
At 39 light-years (229 trillion miles) from Earth, the system is relatively close to us, in the constellation Aquarius. It is called TRAPPIST-1, named for the Transiting Planets and Planetesimals Small Telescope (TRAPPIST) in Chile. In May 2016, researchers using TRAPPIST announced they had discovered three planets in the system. Assisted by several ground-based telescopes, including the European Southern Observatory's Very Large Telescope, Spitzer confirmed the existence of two of these planets and discovered five additional ones, increasing the number of known planets in the system to seven.
The new results were published yesterday in the journal Nature, and announced at a news briefing at NASA Headquarters in Washington. Using data from Spitzer, the team precisely measured the sizes of the seven planets and developed first estimates of the masses of six of them, allowing their density to be estimated. Based on their densities, all of the TRAPPIST-1 planets are likely to be rocky. Further observations will not only help determine whether they are rich in water, but also possibly reveal whether any could have liquid water on their surfaces. The mass of the seventh and farthest exoplanet has not yet been estimated – scientists believe it could be an icy, "snowball-like" world, but further observations are needed.
"The seven wonders of TRAPPIST-1 are the first Earth-size planets that have been found orbiting this kind of star," said Michael Gillon, lead author of the paper and the principal investigator of the TRAPPIST exoplanet survey at the University of Liege, Belgium. "It is also the best target yet for studying the atmospheres of potentially habitable, Earth-size worlds."
Artist's impression of the surface environment on TRAPPIST-1f, one of the newly discovered planets in the TRAPPIST-1 system. Credits: NASA/JPL-Caltech
In contrast to our Sun, the TRAPPIST-1 star – classified as an ultra-cool dwarf – is so cool that liquid water could survive on planets orbiting very close to it, closer than is possible on planets in our solar system. All seven of the TRAPPIST-1 planetary orbits are closer to their host star than Mercury is to our sun. The planets are also very close to each other. If a person was standing on one of the planet's surface, they could gaze up and potentially see geological features or clouds of neighbouring worlds, which would sometimes appear larger than the Moon in Earth's sky [see interactive 360° video here].
The planets may also be tidally locked to their star, which means the same side of the planet is always facing the star; therefore each side is either perpetual day or night. This could mean they have weather patterns totally unlike those on Earth, such as strong winds blowing from the day side to the night side, and extreme temperature changes.
Spitzer, an infrared telescope that trails Earth as it orbits the sun, was well-suited for studying TRAPPIST-1 because the star glows brightest in infrared light, whose wavelengths are longer than the eye can see. In the fall of 2016, Spitzer observed TRAPPIST-1 nearly continuously for 500 hours. Spitzer is uniquely positioned in its orbit to observe enough crossing – transits – of the planets in front of the host star to reveal the complex architecture of the system. Engineers optimised Spitzer's ability to observe transiting planets during its "warm mission," which began after the spacecraft's coolant ran out as planned after the first five years of operations.
"This is the most exciting result I have seen in the 14 years of Spitzer operations," said Sean Carey, manager of NASA's Spitzer Science Center at Caltech/IPAC in Pasadena, California. "Spitzer will follow up in the fall to further refine our understanding of these planets so that the James Webb Space Telescope can follow up. More observations of the system are sure to reveal more secrets."
Following up on the Spitzer discovery, NASA's Hubble Space Telescope has initiated the screening of four of the planets, including the three inside the habitable zone. These observations aim at assessing the presence of puffy, hydrogen-dominated atmospheres, typical for gaseous worlds like Neptune, around these planets.
Credit: ESO/O. Furtak
In May 2016, the Hubble team observed the two innermost planets, and found no evidence for such puffy atmospheres. This strengthened the case that the planets closest to the star are rocky in nature.
"The TRAPPIST-1 system provides one of the best opportunities in the next decade to study the atmospheres around Earth-size planets," said Nikole Lewis, co-leader of the Hubble study and astronomer at the Space Telescope Science Institute in Baltimore, Maryland. NASA's planet-hunting Kepler Space Telescope also is studying the TRAPPIST-1 system, making measurements of the star's minuscule changes in brightness due to transiting planets. Operating as the K2 mission, the spacecraft's observations will allow astronomers to refine the properties of the known planets, as well as search for additional planets in the system. The K2 observations conclude in early March and will be made available on the public archive.
Spitzer, Hubble, and Kepler will help astronomers plan for follow-up studies using NASA's upcoming James Webb Space Telescope, launching in 2018. With much greater sensitivity, Webb will be able to detect the chemical fingerprints of water, methane, oxygen, ozone, and other components of a planet's atmosphere. Webb will also analyse planets' temperatures and surface pressures – key factors in assessing their habitability.
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17th February 2017
Organic material identified on Ceres
NASA's Dawn mission has found evidence of organic material on Ceres – the first clear detection of organic molecules from orbit on a main asteroid belt object.
Dawn has detected organic-rich areas on Ceres, the largest object in the asteroid field between the orbits of Mars and Jupiter. Scientists evaluating the geology of the regions conclude that the organics are most likely native to the dwarf planet. Data from the spacecraft suggest that the interior of Ceres is the source of these organic materials, as opposed to arriving via impacting asteroids or comets, according to a paper published today in Science.
"This discovery of a locally high concentration of organics is intriguing, with broad implications for the astrobiology community," says Dr. Simone Marchi, senior research scientist at Southwest Research Institute in Texas and co-author of the paper. "Ceres has evidence of ammonia-bearing hydrated minerals, water ice, carbonates, salts, and now organic materials. With this new finding, Dawn has shown that Ceres contains key ingredients for life."
Ceres is believed to have originated about 4.5 billion years ago, when planets and moons were forming. Studying it can help to explain the origin, evolution and distribution of organics across the Solar System. Data from Dawn's visible and infrared mapping spectrometer show an unusually high concentration of organic matter close to the 50-km diameter Ernutet crater in the northern hemisphere of Ceres. The distribution and characteristics of the organics seem to preclude association with any single crater. The largest concentration appears to drape discontinuously across the southwest floor and rim of Ernutet and onto an older, highly degraded crater. Other organic-rich areas are scattered to the northwest. While other scientists looked at the distribution and spectra of the materials, Marchi focused on the geological settings.
Size comparison of Ceres, the Moon and Earth.
"The overall region is heavily cratered and appears to be ancient; however, the rims of Ernutet crater appear to be relatively fresh," Marchi said. "The organic-rich areas include carbonate and ammoniated species, which are clearly Ceres' endogenous material, making it unlikely that the organics arrived via an external impactor."
Ceres shows clear signatures of pervasive hydrothermal activity, aqueous alteration and fluid mobility, so the organic-rich areas may be the result of internal processes. Dawn scientists will continue to study the dwarf planet to identify a viable method for transporting such material from the interior to the surface in the pattern observed.
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15th February 2017
Dubai unveils "Mars 2117 Project"
The United Arab Emirates has announced an ambitious long-term project that aims to build the first city on Mars by 2117.
Credit: Dubai Media Office
At the 5th World Government Summit yesterday, Dubai ruler Sheikh Mohammed bin Rashid Al Maktoum announced the "Mars 2117 Project" which aims to build a miniature city on the Red Planet within 100 years.
“This new project is a seed that we plant today, and we expect future generations to reap the benefits – driven by a passion to learn, to unveil new knowledge,” said Sheikh Mohammed. “The landing of people on other planets has been a long-time dream for humans. Our aim is that the UAE will spearhead international efforts to make this dream a reality.”
In the near term, the UAE will focus on developing its education system, he said, to equip its people with the science and technical skills required for leading research across various sectors. The knowledge that flows from the project will be made available to research institutions around the world to foster collaborations and partnerships in the fields of energy, food, housing, mobility, space travel and transportation. These efforts will not only go towards advancing the Mars project, but will also help to improve people's lives here on Earth.
The UAE is becoming "part of a global scientific drive to explore space, and we hope to serve humanity through this project," said the Crown Prince of Abu Dhabi, Mohammed Bin Zayed Al Nahyan, who also attended the event.
Credit: Dubai Media Office
During the summit, an Emirati team of engineers and scientists presented a concept for the first city on Mars, which they said would be built by robots. Their plan highlighted the expected lifestyle on Mars in terms of transport, energy and food production, as well as materials needed for construction. Developing faster means of travel between Earth and Mars will be a key objective, according to the researchers.
Working on a project with such a lengthy timescale may seem misguided. Who knows what the world might look like in 100 years? However, the UAE seems more and more determined to prove itself as a major player in the space industry. In 2015, the government reaffirmed its commitment to sending an unmanned probe to Mars in 2021, which will become the first Arabian mission to Mars and is timed to coincide with the 50th anniversary of the country's establishment. Sheikh Mohammed is renowned for embracing technology and innovation – transforming Dubai into a global city; launching a number of major enterprises; and driving development of numerous mega-projects like the Palm Islands and Burj Khalifa, the tallest tower in the world.
Credit: Dubai Media Office
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13th February 2017
NASA reveals plan for Europa surface lander in 2031
NASA has published a report outlining the mission goals of an unmanned Europa surface lander and which instruments the probe may need.
Europa is one of the four Galilean moons orbiting Jupiter, and is the sixth-largest moon in the Solar System. It has the smoothest surface of any known solid object in our Solar System. The apparent youth and smoothness of the surface have led to the hypothesis that a water ocean exists beneath it, which could conceivably harbour extraterrestrial life.
In addition to telescopes, Europa has been imaged by a succession of space probe flybys, the first occurring in the early 1970s. More missions will be conducted in the future including the Jupiter Icy Moon Explorer (JUICE), a mission to Ganymede that will include two flybys of Europa. NASA's planned Europa Clipper will also be launched in the next several years.
No spacecraft has ever landed, or is scheduled to land, on the surface of Europa. It has been estimated that doing so could add as much as $1 billion to a mission's total cost. However, there are signs that such an expedition may be starting to move forward, as NASA has just released a highly detailed 264-page report, outlining the potential goals and scientific instruments the agency may want to have.
If approved, this mission would be launched in 2024 aboard the next-generation Space Launch System, arriving in 2031. It would perform the first in situ search for evidence of life on another world since the Viking spacecraft on Mars in the 1970s. The lander would dig down at least 10 cm (4 inches) below the surface and obtain five or more samples, analysing the material's organic and inorganic contents. Each sample would be studied under a microscope "capable of distinguishing microbial cells as small as 0.2 microns in diameter, and as dilute as 100 cells per cubic centimeter" according to the report.
In addition to its suite of instruments for analysing the samples, the lander would be equipped with a pair of colour stereo imagers, for examining the landing site in 3-D (including capabilities for characterising the surface composition), and a seismic package for determining Europa’s ice and ocean thickness via acoustic monitoring of cracking events in the ice shell. The lander's proximity to liquid water would be determined, as well as the composition of recently erupted materials from ice plumes. The mission would also look for the most promising places to explore in the future.
Due to the extreme radiation of nearby Jupiter, it's unlikely that any life (as we know it) could survive for very long above ground. The spacecraft, too, would have only a short lifespan of about 20 days on the surface, before its electronics were destroyed. Those 20 days could prove to be invaluable for astrobiologists and may revolutionise our understanding of one of the most fascinating places in the Solar System.
Credit: K.P. Hand et al / NASA
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27th January 2017
Metallic hydrogen created for the first time
Scientists at Harvard have created a small amount of metallic hydrogen for the first time, a century after it was theorised. This material is thought to be present in the depths of gas giants like Jupiter.
Photographs of hydrogen at different stages of compression: Transparent molecular hydrogen (left) at about 200 GPa, which is converted into black molecular hydrogen at 415 GPa (middle), and finally reflective atomic metallic hydrogen at 495 GPa (right).
Credit: Isaac Silvera / Harvard
Nearly a century after it was theorised, Harvard scientists claim to have succeeded in creating the rarest – and potentially one of the most valuable – materials on the planet.
The material – atomic metallic hydrogen – was created by Professor of Natural Sciences, Isaac Silvera; and his colleague, post-doctoral fellow Ranga Dias. As well as helping scientists answer fundamental questions about the nature of matter, this material is theorised to have a wide range of applications, including as a room-temperature superconductor. The breakthrough is described in a paper published yesterday by the journal Science.
"This is the holy grail of high-pressure physics," Silvera said. "It's the first-ever sample of metallic hydrogen on Earth, so when you're looking at it, you're looking at something that's never existed before."
To create it, Silvera and Dias squeezed a tiny hydrogen sample at 495 gigapascal (GPa), or more than 71 million pounds-per-square inch – greater than the pressure at the centre of the Earth. At those extreme pressures, Silvera explained, solid molecular hydrogen – which consists of molecules on the lattice sites of the solid – breaks down, and the tightly bound molecules dissociate to transforms into atomic hydrogen, which is a metal.
Comparison of this study with other studies. Solid metallic hydrogen was achieved at 495 GPa.
While the work offers an important new window into understanding the general properties of hydrogen, it also offers tantalising hints at potentially revolutionary new materials.
"One prediction that's very important is metallic hydrogen is predicted to be meta-stable," Silvera said. "That means if you take the pressure off, it will stay metallic, similar to how diamonds form from graphite under intense heat and pressure, but remain diamond when pressure and heat is removed."
Understanding whether the material is stable is important, Silvera said, because predictions suggest metallic hydrogen could act as a superconductor at room temperatures.
"That would be revolutionary," he said. "As much as 15 percent of energy is lost to dissipation during transmission, so if you could make wires from this material and use them in the electrical grid, it could change that story."
Among the holy grails of physics, a room temperature superconductor, Dias said, could radically change our transportation system, making magnetic levitation of high-speed trains possible, as well as ultra-efficient electric cars and improving the performance of many electronic devices. It could also provide major improvements in energy production and storage, because superconductors have zero resistance energy that could be stored by maintaining currents in superconducting coils, and then used when needed.
In addition to transforming life on Earth, metallic hydrogen could also play a key role in helping humans explore the far reaches of space, as the most powerful rocket propellant yet discovered.
"It takes a tremendous amount of energy to make metallic hydrogen," Silvera explained. "And if you convert it back to molecular hydrogen, all that stored energy is released, so it would make it the most powerful rocket propellant known to man, and could revolutionise rocketry."
The most powerful fuels in use today have a "specific impulse" of 450 seconds – a measure, in seconds, of how fast a propellant is fired from the back of a rocket. In other words, a typical chemical rocket engine can produce one pound of thrust from one pound of fuel for 450 seconds. By comparison, the specific impulse for metallic hydrogen is theorised to be 1,700 seconds.
"That would easily allow you to explore the outer planets," Silvera said. "We would be able to put rockets into orbit with only one stage, versus two, and could send up larger payloads. So it could be very important."
To create the new material, Silvera and Dias turned to one of the hardest materials on Earth – diamond. But rather than natural diamond, Silvera and Dias used two small pieces of carefully polished synthetic diamond which were then treated to make them even tougher and then mounted opposite each other in a device known as a diamond anvil cell.
"Diamonds are polished with diamond powder, and that can gouge out carbon from the surface," Silvera said. "When we looked at the diamond using atomic force microscopy, we found defects, which could cause it to weaken and break."
The solution, he said, was to use a reactive ion etching process to shave a tiny layer – just five microns thick, or about one-tenth of a human hair – from the diamond's surface. The diamonds were then coated with a thin layer of alumina to prevent the hydrogen from diffusing into their crystal structure and embrittling them.
After more than four decades of work on metallic hydrogen, and nearly a century after it was first theorised, seeing the material for the first time, Silvera said, was thrilling.
"It was really exciting," he said. "Ranga was running the experiment, and we thought we might get there, but when he called me and said, 'The sample is shining,' I went running down there, and it was metallic hydrogen. I immediately said we have to make the measurements to confirm it, so we rearranged the lab... and that's what we did. It's a tremendous achievement – and even if it only exists in this diamond anvil cell at high pressure, it's a very fundamental and transformative discovery."
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10th January 2017
Hubble provides interstellar road map for Voyager probes
Astronomers using NASA's Hubble Space Telescope have measured the material along the Voyager 1 and 2 probes' trajectories as they move through space. Hubble data, combined with the Voyagers, have also provided new insights into how our Sun travels through interstellar space.
Credit: NASA, ESA, and J. Zachary and S. Redfield (Wesleyan University); and G. Bacon (STScI)
NASA's two Voyager spacecraft are hurtling through unexplored territory on their road trip beyond our Solar System. Along the way, they are measuring the interstellar medium, the mysterious environment between stars. NASA's Hubble Space Telescope is providing the road map – by measuring the material along the probes' trajectories as they move through space. Even after the Voyagers run out of electrical power and are unable to send back new data, which may happen in the mid-2020s, astronomers can use Hubble observations to characterise the environment through which these silent ambassadors will glide.
A preliminary analysis from Hubble reveals a rich and complex interstellar ecology, containing multiple clouds of hydrogen laced with other elements. Hubble data – combined with the Voyagers' – have also provided new insights into how our Sun travels through interstellar space.
"This is a great opportunity to compare data from in situ measurements of the space environment by the Voyager spacecraft and telescopic measurements by Hubble," said study leader Seth Redfield of Wesleyan University in Middletown, Connecticut. "The Voyagers are sampling tiny regions as they plough through space at 38,000 miles per hour. But we have no idea if these small areas are typical or rare. The Hubble observations give us a broader view, because the telescope is looking along a longer and wider path. So Hubble gives context to what each Voyager is passing through."
It is hoped that Hubble will help characterise the physical properties of the local interstellar medium. "Synthesising these insights with in situ measurements from Voyager would provide an unprecedented overview of the local interstellar environment," said Hubble team member Julia Zachary, also of Wesleyan University.
NASA launched the twin Voyager 1 and 2 probes in 1977. Both explored the gas giants Jupiter and Saturn, with Voyager 2 going on to visit the outer planets Uranus and Neptune. Voyager 1 is now zooming through interstellar space, the region between star systems that contains gas, dust, and material recycled from dying stars. At 13 billion miles from Earth, Voyager 1 is the farthest human-made object ever built. In about 40,000 years, it will pass within 1.6 light-years of the star Gliese 445. Its twin, Voyager 2, currently 10.5 billion miles away, will reach Sirius in approximately 298,000 AD.
For the next decade or so, until they lose electrical power, the Voyagers will take measurements of interstellar material, magnetic fields and cosmic rays along their trajectories. As shown on the diagram below (click to enlarge), Hubble complements the Voyagers' observations by gazing at two sightlines along each spacecraft's path to map the interstellar structure along their star-bound routes. Each sightline stretches several light-years to nearby stars. Sampling the light from those stars, Hubble's imaging spectrograph can measure how interstellar material absorbs some of the starlight, leaving tell-tale spectral fingerprints.
Click to enlarge
Credit: NASA, ESA, and Z. Levy (STScI)
Based on the Hubble data gathered so far, the astronomers predict that Voyager 2 will move out of the interstellar cloud surrounding our Solar System in a couple of thousand years. It will spend another 90,000 years in a second cloud, before passing into a third.
An inventory of the clouds' composition reveals slight variations in the abundances of chemical elements contained in the structures. "These variations could mean the clouds formed in different ways, or from different areas, and then came together," Redfield said.
Early analysis of the Hubble data also suggests that the Sun is passing through clumpier material in nearby space, which might affect the heliosphere – the large "bubble" containing our Solar System that is produced by our Sun's powerful solar wind. At its boundary, called the heliopause, the solar wind pushes outward against the interstellar medium. Hubble and Voyager 1 made measurements of the interstellar environment beyond this boundary, where the wind comes from stars other than our Sun.
"I'm really intrigued by the interaction between stars and the interstellar environment," Redfield said. "These kinds of interactions are happening around most stars, and it is a dynamic process."
The heliosphere is compressed when the Sun moves through dense material, but it expands back out when the star passes through low-density matter. This expansion and contraction is caused by the interaction between the outward pressure of the stellar wind, composed of a stream of charged particles, and the pressure of the interstellar material surrounding the star.
The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Centre in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington, D.C. The Voyagers were built by the Jet Propulsion Laboratory (JPL), which continues to operate both spacecraft.
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8th January 2017
NASA announces new space probes for the 2020s
NASA has announced its choices for the next Discovery Program missions – Lucy, a probe that will visit several asteroids including the Trojans, and Psyche, to study the large metallic asteroid 16 Psyche.
Credits: SwRI and SSL/Peter Rubin
NASA has selected two missions that have the potential to open new windows on one of the earliest eras in the history of our Solar System – a time less than 10 million years after the birth of our Sun. The missions, known as Lucy and Psyche, were chosen from 27 candidates that were narrowed down to five finalists in October 2015. They will now proceed to mission formulation, with the goal of launching in 2021 and 2023, respectively.
"Lucy will visit a target-rich environment of Jupiter's mysterious Trojan asteroids, while Psyche will study a unique metal asteroid that's never been visited before," said Thomas Zurbuchen, associate administrator for NASA's Science Mission Directorate in Washington. "This is what Discovery Program missions are all about – boldly going to places we've never been to enable groundbreaking science."
Lucy is scheduled to launch in 2021 and expected to arrive at its first destination, a main belt asteroid, in 2025. From 2027 to 2033, Lucy will explore six Jupiter Trojan asteroids. These asteroids are trapped by Jupiter's gravity in two swarms that share the planet's orbit, one leading and one trailing Jupiter in its 12-year circuit around the Sun. The Trojans are thought to be relics of a much earlier era in the history of the Solar System, and may have formed far beyond Jupiter's current orbit.
"This is a unique opportunity," said Harold Levison, lead investigator for the Lucy mission. "Because the Trojans are remnants of the primordial material that formed the outer planets, they hold vital clues to deciphering the history of the Solar System. Lucy, like the human fossil for which it is named, will revolutionise the understanding of our origins."
Lucy will build on the success of NASA's New Horizons mission to Pluto and the Kuiper Belt – using more advanced versions of the scientific instruments that have enabled that probe's achievements. Several members of the Lucy mission team are also veterans of the New Horizons mission. Lucy will also build on the success of the OSIRIS-REx mission to asteroid Bennu, with the OTES instrument and several members of the OSIRIS-REx team.
Meanwhile, the Psyche mission will explore one of the most intriguing targets in the main asteroid belt – a giant metal asteroid, known as 16 Psyche, about three times farther away from the Sun than is the Earth. This asteroid measures about 130 miles (210 km) in diameter and, unlike most other asteroids that are rocky or icy bodies, is thought to be composed primarily of metallic iron and nickel, similar to Earth's core. Astronomers wonder whether 16 Psyche could be an exposed core of an early planet that could have been as large as Mars, but which lost its rocky outer layers due to violent collisions billions of years ago. The mission will help scientists understand how planets and other bodies were separated into their layers – including cores, mantles and crusts – early in their histories.
"This is an opportunity to explore a new type of world – not one of rock or ice, but of metal," said Psyche's principal investigator, Lindy Elkins-Tanton of Arizona State University in Tempe. "16 Psyche is the only known object of its kind in the Solar System, and this is the only way humans will ever visit a core. We learn about inner space by visiting outer space."
Psyche, also a robotic mission, is targeted to launch in October of 2023, arriving at the asteroid in 2030, following an Earth gravity assist spacecraft manoeuvre in 2024 and a Mars flyby in 2025.
In addition to selecting Lucy and Psyche for mission formulation, the agency will extend funding for the Near Earth Object Camera (NEOCam) project for an additional year. The NEOCam space telescope is designed to survey regions of space closest to Earth's orbit, where potentially hazardous asteroids may be found.
"These are true missions of discovery that integrate into NASA's larger strategy of investigating how the Solar System formed and evolved," said NASA's Planetary Science Director Jim Green. "We've explored terrestrial planets, gas giants, and a range of other bodies orbiting the Sun. Lucy will observe primitive remnants from farther out in the Solar System, while Psyche will directly observe the interior of a planetary body. These additional pieces of the puzzle will help us understand how the Sun and its family of planets formed, changed over time, and became places where life could develop and be sustained – and what the future may hold."
Discovery-class missions like these are relatively low-cost, with development capped at $450 million. The Discovery Program portfolio includes 12 prior selections such as the MESSENGER mission to study Mercury, the Dawn mission to explore asteroids Vesta and Ceres, and the InSight Mars lander, scheduled to launch in May 2018.
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29th November 2016
The speed of light could be variable, say researchers
Scientists behind a theory that the speed of light is variable – and not constant as Einstein suggested – have produced a model with an exact figure on the spectral index, which they say is testable.
Scientists behind a theory that the speed of light is variable – and not constant as Einstein suggested – have made a prediction that could be tested.
Einstein observed that the speed of light remains the same in any situation, and this meant that space and time could be different in different situations.
The assumption that the speed of light is fixed, and always has been, underpins many theories in physics, such as Einstein's theory of general relativity. It plays an especially important role in models of what happened during the very early universe, seconds after the Big Bang.
But some researchers have suggested that the speed of light could have been much higher in this early universe. Now, one of this theory's originators, Professor João Magueijo from Imperial College London, working with Dr Niayesh Afshordi at the Perimeter Institute in Canada, has made a prediction that could be used to test the theory's validity.
Large structures, such as galaxies, all formed from fluctuations in the early universe – tiny differences in density from one region to another. A record of these early fluctuations is imprinted on the cosmic microwave background – a map of the oldest light in the universe – in the form of a 'spectral index'.
Working with their theory that the fluctuations were influenced by a varying speed of light in the early universe, Professor Magueijo and Dr Afshordi have now used a model to put an exact figure on the spectral index. The predicted figure and model it is based on are published this month in the peer-reviewed journal Physical Review D.
Cosmologists have been getting ever more precise readings of this figure, so the prediction could soon be tested – either confirming or ruling out the team's model of the early universe. Their figure is a very precise 0.96478. This is close to the current estimate of readings of the cosmic microwave background, which puts it around 0.968, with some margin of error.
"The theory, which we first proposed in the late-1990s, has now reached a maturity point – it has produced a testable prediction. If observations in the near future do find this number to be accurate, it could lead to a modification of Einstein's theory of gravity," explains Professor Magueijo. "The idea that the speed of light could be variable was radical when first proposed – but with a numerical prediction, it becomes something physicists can actually test. If true, it would mean that the laws of nature were not always the same as they are today."
The testability of the varying speed of light theory sets it apart from the more mainstream rival theory: inflation. Inflation says that the early universe went through an extremely rapid expansion phase, much faster than the current rate of expansion of the universe.
Credit: By Yinweichen, [CC BY-SA 3.0], via Wikimedia Commons
These theories are necessary to overcome what physicists call the 'horizon problem'. The universe as we see it today appears to be everywhere broadly the same. For example, it has a relatively homogenous density.
This could only be true if all regions of the universe were able to influence each other. However, if the speed of light has always been the same, then not enough time has passed for light to have travelled to the edge of the universe, and 'even out' the energy.
As an analogy, to heat up a room evenly, the warm air from radiators at either end has to travel across the room and mix fully. The problem for the universe is that the 'room' – the observed size of the universe – appears to be too large for this to have happened in the time since it was formed.
The varying speed of light theory suggests that the speed of light was much higher in the early universe, allowing the distant edges to be connected as the universe expanded. The speed of light would have then dropped in a predictable way as the density of the universe changed. This variability led the team to their prediction published this month.
The alternative theory is inflation, which attempts to solve this problem by saying that the very early universe "evened out" while incredibly small, and then suddenly expanded, with the uniformity already imprinted on it. While this means the speed of light and the other laws of physics as we know them are preserved, it requires the invention of an 'inflation field' – a set of conditions that only existed at the time.
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24th November 2016
Huge deposit of water ice found below surface of Mars
NASA reports that its Mars Reconnaissance Orbiter has found a huge deposit of water ice just under the surface of the planet Mars, in the region known as Utopia Planitia.
Utopia Planitia on Mars. Credit: NASA
Frozen beneath a region of cracked and pitted plains on Mars lies a volume of water equivalent to Lake Superior, the largest of the Great Lakes, researchers using NASA's Mars Reconnaissance Orbiter have determined.
Scientists examined part of Mars' Utopia Planitia region, in the mid-northern latitudes, which forms part of the largest recognised impact basin on Mars and in the Solar System with an estimated diameter of 3300 km. It is also where the Viking 2 lander made its historic touchdown in September 1976.
The Mars Reconnaissance Orbiter's ground-penetrating Shallow Radar (SHARAD) instrument was used to record data from over 600 overhead passes, revealing a deposit more extensive in area than the state of New Mexico. The water ice ranges in thickness from about 80 metres (260 feet) to about 170 metres (560 feet) with a composition that is 50 to 85 percent water ice, mixed with dust or larger rocky particles.
At the latitude of this deposit, halfway from the equator to the pole, water ice cannot persist on the surface today. It sublimes into water vapour in the planet's thin, dry atmosphere. The Utopia deposit is shielded from the atmosphere by a soil covering estimated to be 1 to 10 metres (3 to 33 feet) thick.
Click to enlarge
"This deposit probably formed as snowfall accumulating into an ice sheet mixed with dust, during a period in Mars history when the planet's axis was more tilted than it is today," said Cassie Stuurman of the Institute for Geophysics at the University of Texas, Austin. She is the lead author of a report in the journal Geophysical Research Letters.
The name Utopia Planitia translates as the "plains of paradise." The newly surveyed ice deposit represents less than one percent of all known water ice on Mars – but it more than doubles the volume of thick, buried ice sheets known in the northern plains. Ice deposits close to the surface are being considered as a resource for astronauts.
"This deposit is probably more accessible than most water ice on Mars, because it is at a relatively low latitude and it lies in a flat, smooth area where landing a spacecraft would be easier than at some of the other areas with buried ice," said Jack Holt of the University of Texas, co-author of the paper.
Location and distribution of the water ice. Credit: NASA
"It's important to expand what we know about the distribution and quantity of Martian water," said Deputy Project Scientist Leslie Tamppari, of NASA's Jet Propulsion Laboratory. "We know early Mars had enough liquid water on the surface for rivers and lakes. Where did it go? Much of it left the planet from the top of the atmosphere. Other missions have been examining that process. But there's also a large quantity that is now underground ice, and we want to keep learning more about that."
"The ice deposits in Utopia Planitia aren't just an exploration resource, they're also one of the most accessible climate change records on Mars," explains Joe Levy of the University of Texas, a co-author of the new study. "We don't understand fully why ice has built up in some areas of the Martian surface and not in others. Sampling and using this ice with a future mission could help keep astronauts alive, while also helping them unlock the secrets of Martian ice ages."
Evidence of a recent, extreme ice age on Mars was published by the journal Science earlier this year. Just 370,000 years ago, the planet would have appeared more white than red.
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5th November 2016
Construction of the James Webb Space Telescope mirror is completed
After 20 years of development, the successor to the Hubble Space Telescope has reached a major milestone, with its primary mirror now complete and ready for testing prior to a 2018 launch.
Credit: NASA/Chris Gunn
In the massive clean room of NASA's Goddard Space Flight Centre, assembly was finished this week on the James Webb Space Telescope's (JWST) primary mirror. Thousands of people have been involved in its design and construction, including a member of the FutureTimeline forum.
The JWST will replace the aging Hubble Space Telescope (launched in 1990) and provide a fresh pair of eyes on the universe. It will offer unprecedented resolution and sensitivity from long-wavelength visible light, through near-infrared to the mid-infrared. While Hubble has a 2.4 m (7.9 ft) primary mirror, the JWST features a much larger 6.5 m (21.3 ft) mirror, composed of 18 hexagonal segments each measuring 1.3 m (4.2 ft). When combined, these will offer seven times the light collecting area of Hubble, alongside instruments that are 100 times more sensitive.
Located near Sun–Earth Lagrange point 2, about 1.5 million km (930,000 miles) from Earth, a large sunshield will keep its mirror and science instruments below 50 K (−223°C; −370°F). This will minimise interference from external sources of light and heat (like the Sun, Earth, and Moon) as well as from heat emitted by the observatory itself.
When fully operational, the JWST will be the most powerful space telescope ever built, capable of seeing the very first generation of stars which ignited less than 200 million years after the Big Bang – a time when the universe was about 1.4% of its current age.
"Today, we're celebrating the fact that our telescope is finished, and we're about to prove that it works," said John Mather, senior project scientist, at the press conference in Maryland. "We've done two decades of innovation and hard work, and this is the result – we're opening up a whole new territory of astronomy."
The telescope would be powerful enough to spot a bumblebee on the Moon's surface, explained Mather – both in its reflected light, and from body heat emitted by the insect. Its mirrors are so smooth that if you scaled the array to the size of the U.S., the hills and valleys of irregularity would be only a few inches high.
After launch phase environment testing at Goddard Space Flight Centre in Maryland, more cryogenic tests will be performed at the Johnson Space Centre in Houston, Texas. The mirror will then be transported to Northrup Grumman in Los Angeles for the final phase of construction that will connect it to the sunshield and spacecraft bus. If all goes according to plan, the mission will be launched in October 2018.
There are four primary scientific objectives:
• to search for light from the first stars and galaxies that formed in the Universe after the Big Bang;
• to study the formation and evolution of galaxies;
• to understand the formation of stars and planetary systems;
• to study planetary systems and the origins of life.
These goals can be achieved more effectively by observation in near-infrared light, rather than light in the visible part of the spectrum. For this reason, the JWST's instruments will have a much greater capacity for infrared astronomy than Hubble – allowing the study of far more objects and regions obscured by gas and dust; such as molecular clouds where stars are born, circumstellar disks that give rise to planets, and the cores of active galaxies. One of the early goals of the JWST will be to gather enough data to answer which theory is correct about the phenomenon of the dimming light around the mysterious star KIC 8462852.
With a history of major cost overruns and delays, the JWST almost didn't happen. The first realistic budget estimates were around $1.6 billion with a planned launch date of 2011. In that year, however, the U.S. House of Representatives voted to terminate funding, after $3 billion had been spent and 75% of its hardware was in production. Funding was later restored, but capped at $8 billion, with a revised launch date of 2018. The costs have now exceeded $8.7 billion, according to mission director Bill Ochs at this week's news conference.
The JWST is being launched by an Ariane 5 rocket supplied by the European Space Agency (ESA). An adapter ring will be included, in the unlikely event that a major deployment problem occurs. This could be used by a future spacecraft to grapple the observatory. Because of its remote distance, however, the telescope itself will not be serviceable – astronauts will be unable to reach it to fix instruments, unlike the much closer Hubble.
"It's critically important to get it right here on the ground, and that's the purpose for the tests that we're doing here and, most importantly, for the tests when we get it down to Johnson [Space Centre] in Chamber A, the big vacuum chamber," said NASA Administrator Charles Bolden.
The JWST is designed to have a minimum lifetime of 5.5 years after launch, but NASA hopes it can remain in operation for 10 years or more. A number of other, even larger observatories have been proposed for the 2030s and beyond. These include the 11.7 m (38.3 ft) High-Definition Space Telescope and a longer-term concept for a robotically assembled telescope reaching 100 metres in size.
Given these trends in observational capability, combined with exponential growth in the number of exoplanets being found, it seems likely that alien life signatures will be detected in the not-too-distant future.
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4th November 2016
First commercial asteroid prospecting mission to launch by 2020
Planetary Resources, Inc., the asteroid mining company, announced yesterday that it has finalised a 25 million euro agreement that includes direct capital investment of 12 million euros and grants of 13 million euros from the Government of the Grand Duchy of Luxembourg and the banking institution Société Nationale de Crédit et d'Investissement (SNCI). This funding will accelerate the company's technical advancements with the aim of launching the first commercial asteroid prospecting mission by 2020. The milestone fulfilled the intent of the Memorandum of Understanding with the Grand Duchy and its SpaceResources.lu initiative that was agreed upon earlier this year.
"We are excited in welcoming the Grand Duchy as a partner and an investor," said Chris Lewicki, President and CEO of Planetary Resources. "Just as the country's vision and initiative propelled the satellite communications industry through its public-private partnerships, this funding and support will fast-track our business – advancing and building upon our substantial accomplishments. We plan to launch the first commercial asteroid prospecting mission by 2020 and look forward to collaborating with our European partner in this pivotal new industry."
Étienne Schneider, Deputy Prime Minister and Minister of the Economy, Government of Luxembourg, said: "The Grand-Duchy of Luxembourg becoming a shareholder in Planetary Resources seals our partnership and lays the ground of the principles of our cooperation in the years to come, while demonstrating the Government's strong commitment to support the national space sector by attracting innovative activities in space resource utilisation and other related areas. The Grand Duchy has a renowned history in public-private partnerships. In 1985, Luxembourg became one of the founding shareholders of SES, a landmark for satellite telecommunications and now a world leader in this sector."
Planetary Resources is establishing a European headquarters in Luxembourg that will conduct key research and development activities in support of its commercial asteroid prospecting capabilities, as well as support international business activities.
Core hardware and software technologies developed at Planetary Resources were tested in orbit last year. The company's next mission, now undergoing final testing, will validate a thermographic sensor that will precisely measure temperature differences of objects on Earth. When deployed on future commercial asteroid prospecting missions, the sensor will acquire key data related to the presence of water and water-bearing minerals on asteroids. Obtaining and using these key resources in space promises to fast-track the development of off-planet economic activities as the commercial industry continues to accelerate.
Planetary Resources was founded in 2009 by Eric Anderson, Peter Diamandis and Chris Lewicki. The company's vision is to establish a new paradigm for resource utilisation that will bring the Solar System within humanity's economic sphere of influence. The pathway to identifying the most commercially viable near-Earth water-rich asteroids has led to the development of multiple transformative technologies that are applicable to global markets, including the agriculture, energy, mining and insurance industries. Planetary Resources is financed by industry-launching visionaries who are committed to expanding the world's resource base so humanity can continue to grow and prosper for centuries to come.
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16th October 2016
The world's first nation state in space
At a press conference in Paris this week, plans were announced for the creation of 'Asgardia' – the first nation state in outer space.
Named after the city of the skies in Norse mythology, Asgardia is a space-based nation proposed by Dr Igor Ashurbeyli, founder of the Aerospace International Research Centre (Vienna), and Chairman of UNESCO's Science of Space committee. The concept is aimed at creating a new framework for how space activities are regulated and owned, ensuring that "the future of space is peaceful and done for the benefit of humankind."
Dr Ashurbeyli, one of the Russian Federation's most distinguished scientists, has consulted globally renowned scientists, engineers, entrepreneurs and legal experts on the development of the concept. The project's official website is currently requesting people to register for "citizenship" with the aim of applying to the United Nations for official recognition as a nation state. Already, hundreds of thousands have signed up.
As a first step, the organisation plans to crowd-source a satellite for launch in 2017, sixty years after Sputnik 1, the first ever satellite. This will mark a new era in the space age, the organisation claims, as the satellite will be independent of any current nation state on Earth: the satellite will comprise the nation itself – creating its own legal system, flag and other symbols of nationhood.
"The project's concept comprises three parts – philosophical, legal and scientific/technological," Dr Ashburbeyli explained. "Asgardia is a fully-fledged and independent nation, and a future member of the United Nations – with all the attributes this status entails. The essence of Asgardia is 'Peace in Space', and the prevention of Earth's conflicts being transferred into space.
"Asgardia is also unique from a philosophical aspect: to serve entire humanity and each and everyone, regardless of his or her personal welfare and the prosperity of the country where they happened to be born. The scientific and technological component of the project can be explained in just three words – peace, access and protection. The scientific and technological envelope of Asgardia is a space arena for the scientific creativity of its citizens and companies in developing a broad range of future space technologies, products and services for humanity on Earth and humanity in space."
In recent years, access to space has been opening up, but the process remains slow and is tightly controlled by states on Earth, restricting commerce and scientific developments by private enterprise. Of the 196 nation states, just thirteen (China, France, India, Iran, Israel, Japan, North Korea, Russia/former USSR, South Korea, UK, Ukraine, USA) and one regional organisation (the European Space Agency, ESA) have independently launched satellites on their own indigenously developed launch vehicles.
Professor David Alexander, Director of the Rice Space Institute at Rice University in Texas: "As low-Earth orbit becomes more accessible, what's often called the 'democratisation' of space, a pathway is opening up to new ideas and approaches from a rich diversity of participants. The mission of Asgardia to create opportunities for broader access to space, enabling non-traditional space nations to realise their scientific aspirations is exciting."
Under current international space law, including the widely adopted Outer Space Treaty, states are required to authorise and supervise national space activities, including the activities of commercial and not-for-profit organisations. Objects launched into space are subject to their nation of belonging and if a nation launches an object into space, that nation is responsible for any damage that occurs internationally and in outer space.
Asgardia aims to create a new framework for ownership and nationhood in space, adapting current laws governing responsibility, private ownership and enterprise so they are fit for purpose in the new era of space exploration. By creating a new "space nation", private enterprise, innovation and the further development of space technology to support humanity could flourish, free from the tight restrictions of state control that currently exist.
Professor Ram Jakhu, Director, Institute of Air and Space Law at McGill University, Montreal, Canada: "An appropriate and unique global space legal regime is indispensable for governing outer space in order to ensure it is explored on a sustainable basis, for exclusively peaceful purposes and to the benefit of all humanity – including future generations living on planet Earth and in outer space. The development of foundational principles of such a legal regime ought to take place at the same time as technological progress is being made."
One of the early developments planned by Asgardia's team will be the creation of a state-of-the-art protective shield for all humankind from cosmic manmade and natural threats to life on Earth such as space debris, coronal mass ejections and asteroid collisions.
There are estimated to be more than 20,000 traceable objects of man-made space debris (MSD) including non-active spacecraft, upper-stage rockets and final stage vehicles, as well as fragments of craft that potentially pose a danger in near-Earth orbits. The impact of the Chelyabinsk meteorite which crashed over a Russian town as recently as 2013, injuring 1,100 people and damaging 4,000 buildings, is a reminder of the threat that natural objects pose to life on our planet.
Whilst steps have already been taken by the UN and the Space Mission Planning Advisory Group (SMPAG) to identify potentially hazardous scenarios, Asgardia will build on these developments to offer a more comprehensive mechanism.
Dr. Joseph N. Pelton, former Dean of the International Space University in Strasbourg, France: "The Asgardia project, among other things, may help prepare better answers to the future governance of outer space – a topic of major concern to the United Nations. The exciting aspect of this initiative is its three phase approach to providing broader access to space; promoting peace in outer space; and addressing cosmic hazards and planetary defence."
The Asgardia Project Team will comprise a collaborative, multi-disciplinary effort from leading experts around the globe which it is envisaged will grow over time as the project evolves. But as well as expert involvement in the project, Asgardia is looking to capture the wider public imagination by crowd-sourcing key aspects of the missions and involving members of the public in competitions – for example, to help design the nation's flag, insignia and other symbols of nationhood.
To coincide with the press conference, a website with further details was launched at www.asgardia.space. The project can also be followed on Twitter where updates will be provided, along with interaction between the Asgardia team and members of the public.
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15th October 2016
The next 5,000 years
A guest piece by sci-fi author Drew Wagar.
In this guest piece, we talked to sci-fi author Drew Wagar about his predictions for the next five, 50, 500 and 5,000 years.
Being an SF writer means you have to imagine different futures, different worlds. It is generally easier to do that when you aren’t tied to the present, or you can pick another world or civilisation and use your imagination.
Predicting where we might be in the future is rather more tricky, and, almost certainly, is going to be wrong – but it’s a fun exercise and here are my thoughts on where we might be...
The next 5 years (2021)
This period is probably the hardest as it is most likely to be wrong, or at least, proved as inaccurate by progress!
On the technology front, 3D printing is one to watch in the next few years; it has the potential to revolutionise the provision and transport of items, in the same way that email displaced the letter. 4G (and better) mobile network access will become the norm for all devices, relegating ‘wired’ connections to history for most users. 2 terabyte SD cards will appear in this time frame. Storage will soon cease to be an issue for most users.
Entertainment will continue to shift away from traditional broadcast media and print to reality augmented and deeply personalised content. I suspect there will be interesting developments as VR and augmented reality leaves the realms of ‘geekdom’ and moves into the mainstream.
I fear the divide between the haves and have-nots will continue to widen, with continued social unrest. For those without means, the future looks bleaker. Pension provision will continue to erode with massive numbers wakening to the realisation that they will never be able to stop working. Debt will continue to force reductions in public spending, against an outcry regarding social welfare. Unfortunately, the traditional ‘left’ will continue to field unworkable and outdated solutions to these problems and leave unfettered capitalism as the unopposed solution.
We will spectacularly fail to get to grips with the burgeoning climate crisis, due to political lobbying, ignorance and the impact of religion world-wide. The 2020s will open with territorial conflicts over oil, water and food supply, enflamed by religious disputes continuing or even worse than the 2010s.
The next 50 years (2066)
Being optimistic I’m going to give us commercially available fusion power in this time period. This effectively ends the ‘oil years’ and makes a range of technology obsolete. Prior to this though, ‘history’ is punctuated by wars both big and small over the diminishing resources of the old carbon economy and the disastrous impacts of climate change.
Personalised electronics, coupled with emerging genetics and nanotechnology continues to expand, with the youngest generation having no qualms about integrating electronics to augment their minds and bodies. The first signs of ‘pure humans’ and ‘augmented humans’ becoming separate societies begins to appear.
AI becomes a recognisable ‘thing’ in this time period, with many jobs replaced by artificial intelligence, particularly in transport, healthcare and brokerage. There are significant amounts of the planet that are run without any human intervention at all.
The concept of ‘owning’ a car will seem very old-fashioned, along with 9-5 working hours. This will be part of a changing zeitgeist world-wide, as the ‘baby boomer’ generation and their thinking finally dies away. Constant ‘debt’ crises force a change whereby rampant consumerism is replaced by a more pragmatic ‘value for money’ consideration. Credit, loans and debt become dirty words possibly due to a catastrophic financial crash and resultant restructuring.
There remains the strong possibility of a major world conflict in this time period. India and China capitalise on this and become the dominant economic entities, overtaking the United States by mid-century.
Environmental problems grow worse before getting better, with the melting of Arctic sea ice and the widespread collapse of the Antarctic ice shelves. Coastal flooding causes major upheaval. No sea ice at the North Pole becomes the norm. Major displacement of some established coastal areas.
However, there are signs for optimism as the end of the carbon economy favours different nations and those who have invested in alternative energy sources and modern infrastructure.
The next 500 years (2516)
Humanity is now wrestling with an ‘excess energy’ problem, whereby energy production is so cheap and commonplace that excessive heat generation is a major global problem again. Climate engineering is a massive undertaking whereby the levels of greenhouse gases are being reduced to cater for the massive amounts of heat that global energy use is generating.
Small parts of Earth are now ‘off-limits’, marked as enclosures for what came to be known as ‘pure humans’ prior to the event known by historians as the ‘Schism’; in this, humanity separated into distinct cultural sects, characterised by their desire to use, or not, selective nano/bio/electronic technology to augment themselves.
The vast majority opted for the enhancements – there was a brief war, which was a forgone conclusion. All illness, mental and physical, deformities were banished as a result. Sex and other dimorphisms ceased to exist. Humans now are partly cybernetic and have abilities that would have been regarded as ‘superpowers’ to humans 500 years before – able to fly, withstand harm and survive extreme acceleration. ‘Pure humans’, without these enhancements, are allowed in the enclosures and left undisturbed to continue their existence. Most consider them fascinating ‘zoo animals’ with hugely limited lifespans and intelligence.
Mars and Venus have been terraformed for the convenience of migration from Earth. They will have been seeded with water from the Kuiper belt and perhaps with minor orbit alterations, courtesy of managed asteroids, to make them even more habitable.
Mining operations across the solar system will have transformed many moons and some planets – though the gas giants will appear largely similar to 21st century eyes.
The next 5,000 years (7516)
Perhaps the most difficult, but certainly the most astonishing changes from the view point of the 21st century.
A major breakthrough in harnessing vacuum energy and a comprehensive understanding of the nature of the universe that eluded 21st century scientists in their entirety now provides the means for humanity to visit other solar systems.
Unlike the imagined crewed spacecraft of thousands of years ago, these ships are merely specialised augmented humans, with humanity’s intelligence, biology crafted into the ship itself. They require no crew, as they are the crew. Humanity explores the stars directly, not by means of primitive physical containers. Much of the galaxy has been mapped.
On Earth, the planet is unrecognisable. Gone is any indication of a transport system, or even major cities. Humanity’s technology is now so advanced that individuals have no need of ‘devices’ whether they are transports, housing, communications or sustenance. Thus the planet now looks utterly unspoilt, returned to an ‘Eden’ of legend. Every individual is utterly self-sufficient in all things.
Culture now revolves around the purest type of entertainment, the exchange of thought, dreams, stories and discovery. Freed from the need to fight to survive, humanity achieves unparalleled greatness.
Drew's books include the Shadeward Saga, a four part sci-fi epic set on the tidally-locked world of Esurio, orbiting the red dwarf star Lacaille 9352.
He is currently writing Elite Dangerous: Premonition, the official Elite Dangerous novel being published by Frontier Developments in 2017. Drew himself is a fan of the game – set in 3302 – in which players can explore a scientifically accurate, virtual recreation of the entire Milky Way galaxy. Featuring what is possibly the largest gaming environment ever created, and playable in VR, Elite Dangerous gives players the chance to travel unimaginable distances, witness breathtaking astronomical sights, land on planetary surfaces, mine asteroids, trade commodities, take part in battles and much more.
Drew lives in Kent with his wife, two sons, a dog and a cat. His favourite colour is dark green. Everything else is subject to change without notice.
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14th October 2016
Universe contains 10 times more galaxies than previously thought
Using 3D imaging techniques on 20 years of photographs by the Hubble Space Telescope, astronomers estimate there are 2 trillion galaxies in the observable universe – an order of magnitude more than previously thought.
A team of astronomers led by Christopher Conselice of the University of Nottingham, UK, has found that 10 times as many galaxies were packed into a given volume of space in the early universe than today. Most of these galaxies were relatively small and faint, with masses similar to those of the satellite galaxies surrounding the Milky Way. As they merged to form larger galaxies, the population density of galaxies in space dwindled. This means that galaxies are not evenly distributed throughout the universe's history.
"These results are powerful evidence that a significant galaxy evolution has taken place throughout the universe's history, which dramatically reduced the number of galaxies through mergers between them – thus reducing their total number," said Conselice. "This gives us a verification of the so-called top-down formation of structure in the universe."
One of the most fundamental questions in astronomy is that of just how many galaxies the universe contains. The landmark Hubble Deep Field – taken in the mid-1990s – gave the first real insight into the universe's galaxy population. Later more sensitive observations, such as Hubble's Ultra Deep Field, revealed a myriad of faint galaxies. This led to an estimate that the observable universe contained about 200 billion galaxies. The new research shows that this estimate must be at least 10 times too low.
Conselice and his team reached this conclusion using deep-space images from Hubble, as well as published data from other teams. They painstakingly converted the images into 3-D, to make accurate measurements of galaxy numbers at different epochs in the universe's history. In addition, they used new mathematical models allowing them to infer the existence of galaxies that the current generation of telescopes cannot observe. This led to the surprising conclusion that for the numbers of galaxies we now see and their masses to add up, there must be a further 90 percent of galaxies in the observable universe that are too faint and too far away to be seen with present-day telescopes. These small, faint galaxies from the early universe merged over time into larger galaxies we can now observe.
Credit: NASA and and Ann Feild [STScI]
"It boggles the mind that over 90 percent of the galaxies in the universe have yet to be studied. Who knows what interesting properties we will find when we discover these galaxies with future generations of telescopes? In the near future, the James Webb Space Telescope will be able to study these ultra-faint galaxies," said Conselice.
The decreasing number of galaxies as time progresses also contributes to the solution for Olbers' paradox (first formulated in the early 1800s by German astronomer Heinrich Wilhelm Olbers): Why is the sky dark at night if the universe contains an infinity of stars? The team came to the conclusion that indeed there actually is such an abundance of galaxies that, in principle, every patch in the sky contains part of a galaxy. However, starlight from the galaxies is invisible to the human eye and most modern telescopes due to other known factors that reduce visible and ultraviolet light in the universe. Those factors are the reddening of light due to the expansion of space, the universe's dynamic nature, and the absorption of light by intergalactic dust and gas. All combined, this keeps the night sky dark to our vision.
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7th October 2016
Saturn's moon Dione may contain a subsurface ocean
The Cassini mission has revealed evidence of a subsurface ocean within Saturn's moon Dione.
The rolling, cratered landscape of Saturn's moon Dione. Credit: NASA/JPL-Caltech/Space Science Institute
A subsurface ocean lies deep within Saturn's moon Dione, according to new data from the Cassini spacecraft. Two other moons of the gas giant – Titan and Enceladus – are already known to hide global oceans beneath their icy crusts, but a new study suggests an ocean exists in Dione as well.
In this study, researchers from the Royal Observatory of Belgium show gravity data from recent Cassini flybys can be explained if Dione's crust floats on an ocean located 100 km (62 miles) below the surface. The ocean is several tens of kilometres deep and surrounds a large rocky core. Seen from within, Dione is similar to its smaller but more famous neighbour Enceladus, whose south polar region spurts huge jets of water vapour into space. Dione seems to be quiet now, but its broken surface bears witness of a more tumultuous past.
The researchers modelled the icy shells of Enceladus and Dione as global icebergs immersed in water, where each surface ice peak is supported by a large underwater keel. Scientists have used this approach in the past, but previous results have predicted a very thick crust for Enceladus and no ocean at all for Dione.
"As an additional principle, we assumed that the icy crust can stand only the minimum amount of tension or compression necessary to maintain surface landforms", said Mikael Beuthe, lead author of the new study. "More stress would break the crust down to pieces."
Dione with Enceladus in the background. Credit: NASA/JPL-Caltech/Space Science Institute.
According to the new study, published in Geophysical Research Letters, Enceladus' ocean is much closer to the surface, especially near the south pole where geysers erupt through a few kilometres of crust. These findings agree well with the discovery last year that Enceladus undergoes large back-and-forth oscillations, or "libration", during its orbit. Enceladus' libration would be much smaller if its crust was thicker. As for Dione, the new study finds it contains a deep ocean between its crust and core.
"Like Enceladus, Dione librates – but below the detection level of Cassini,'' said Antony Trinh, co-author of the study. "A future orbiter hopping around Saturn's moons could test this prediction."
Dione's ocean has probably survived for the whole history of the moon, and thus offers a long-lived habitable zone for microbial life. "The contact between the ocean and the rocky core is crucial", said Attilio Rivoldini, co-author of the study. "Rock-water interactions provide key nutrients and a source of energy, both being essential ingredients for life." The ocean of Dione is too deep for easy access, but Enceladus as well as Jupiter's moon Europa are generous enough to eject water samples in space, ready to be captured by a passing spacecraft.
Size comparison of the Moon, Earth and Dione. Credit: NASA/JPL/Space Science Institute/Gregory H. Revera.
The club of "ocean worlds" – icy moons or planets with subsurface oceans in common parlance – is gaining new members with each new mission to the outer Solar System. Three ocean worlds orbit Jupiter, three orbit Saturn, and Pluto could also belong to the club, according to recent observations of the New Horizons spacecraft. The approach to modelling planetary bodies used in this study is a promising tool to study these worlds if we can measure their shape and gravity field, according to Mikael Beuthe. "Future missions will visit Jupiter's moons, but we should also explore Uranus' and Neptune's systems", he said.
Cassini was launched in 1997 and has been operational since 2004. Next year, on 15th September 2017, its 20-year mission will end as it plunges into Saturn's hydrogen and helium atmosphere.
Dione and Saturn. Credit: NASA / Jet Propulsion Laboratory / Space Science Institute
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28th September 2016
SpaceX founder Elon Musk reveals plan for manned missions to Mars
SpaceX founder and entrepreneur Elon Musk has revealed his plan to send humans to Mars on a new spacecraft, with the first flights beginning in the 2020s.
Yesterday, at the 67th International Astronautical Congress in Guadalajara, Mexico, Elon Musk gave a presentation in which he described his plans to send humans to Mars in the next decade. If successful, this would be achieved using the largest rocket ever designed, to launch a spacecraft capable of delivering up to 100 people into orbit. The rocket booster will be reusable, like SpaceX's existing Falcon 9 rocket, and will return to the launch pad. Another rocket launch would deliver fuel to the awaiting spacecraft, after which solar panels would be unfurled for the remaining journey to Mars.
Musk claims the trip could take as little as 80 days, significantly faster than most of today's unmanned probes that typically need 180 days (six months). Upon its arrival at the Red Planet, the spacecraft would land on its feet using retro-propulsion rockets. It would be named the "Heart of Gold" after the ship commanded by Zaphod Beeblebrox in Douglas Adams' famous novel, The Hitchhiker's Guide to the Galaxy. The astronauts would then step onto the surface of a new planet, becoming the first humans to do so. For return trips to Earth, rocket fuel could be synthesised on Mars from water and CO2.
As for the question of when this could all happen, Musk said he was "intentionally a bit fuzzy about this timeline". However, he wants to begin sending equipment and supplies to Mars every two years, starting with the first Red Dragon mission in 2018. The first humans could follow by the mid-2020s.
Musk is well known for his ambitious schedules when it comes to new technologies, such as electric and self-driving cars. His plans for Mars would be significantly earlier than NASA's intended missions for the 2030s. This has raised concerns regarding the financial and technical feasibility. For example, radiation could be a significant problem for the astronauts, as well as long periods without Earth's gravity, for which a great deal more research is needed to determine the impact on human health. During the presentation, he was also somewhat vague about the growing of food on Mars and the generation of energy. He said nothing about the problem of Martian dust, which not only covers solar panels, but could pose a serious risk to the astronauts' health if breathed in.
In terms of the costs involved, Musk appears confident. While a trip to Mars with current technologies may cost upwards of ten billion dollars, he hopes to bring this down substantially – so that, in the not-too-distant future, a ticket to Mars could be bought for only $100,000. This would enable many thousands of people to settle on Mars within a relatively short time. In addition to funding some aspects of the Mars missions from SpaceX profits, he is seeking backers for a public-private partnership. The interplanetary division of SpaceX currently receives up to $30 million per year in funding – but this will increase substantially after the final version of the Falcon 9 rocket is rolled out. The reusability of the Mars spacecraft, in-orbit refuelling and on-site propellant production would reduce costs by "orders of magnitude".
The Interplanetary Transport System, to give its official name, is not just for Mars. In the longer term, Musk claims the system it uses could be designed for extended missions to the moons of Jupiter and even further into the Solar System. SpaceX has already begun developing the Raptor rocket engine that will power the craft. His presentation also touched on the longer-term possibility of terraforming Mars to make it habitable and Earthlike.
"The thing that Mars really represents is life insurance, ensuring that the light of consciousness is not extinguished, backing up the biosphere," he said at the presentation. "It's not about everybody moving to Mars – it's about becoming multiplanetary."
The full presentation including a downloadable PDF is available on the SpaceX website.
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