By Dr. Alfredo Carpineti
January 30, 2026
Introduction:
Read more here: https://www.iflscience.com/only-two-sp ... ape-82399(IFL Science) The boundary of the Solar System remains somewhat poorly understood. We know we are within it, in a region of space called the heliosphere, where particles released by the Sun dominate. Beyond it, the flow of particles from interstellar space rules. Between the two, where the heliosphere meets interstellar space, are the heliopause and the bow shock. A new NASA mission is set to provide crucial insight into both.
Launched last September, it’s called the Interstellar Mapping and Acceleration Probe (IMAP), and just a couple of weeks ago it reached its final location, a region in space called Lagrange point 1 (L1). This is about 1.5 million kilometers (just under 1 million miles) from Earth, directly towards the Sun. It’s the location where the Sun and Earth’s gravity cancel out, so that the telescope will move around our star in one year.
Close to the center of the Solar System might seem like a peculiar location to study its edges, but the secret of IMAP is that it is designed to study the radiation coming from the heliopause and bow shock.
When the solar wind slams into particles from the interstellar medium, it produces energetic neutral atoms (ENAs). By studying these atoms, IMAP can tell us things about the region and its variability, such as how its shape changes with the activity of the Sun.
From L1, IMAP has a 360-degree view of the heliosphere and also an unobstructed view of the Sun. The mission will also monitor space weather and can provide a 30-minute warning if harmful radiation from the Sun is coming our way.
