In Stereo

ARTEMIS P2 Enters Lunar Orbit

Well, this is kinda cool. NASA has taken two satellites that would have been shut down in 2010 and put them in orbit around the Moon to give us a continual up-close-and-personal view of the  lunar surface from about 60 miles away. The spacecraft, called the Aceleration, Reconnection, Turbulence, and Electrodynamics of the Moon’s Interaction with the Sun (ARTEMIS) probes, arrived at their lunar orbits on June 27th and July 17th, respectively. These twins were once in different areas of near-Earth space, part of a five-spacecraft system called THEMIS (Time History of Events and Macroscale Interactions during Substorms).  Along with three other probes, these two spacecraft  studied the solar wind, Earth’s outer magnetic field, and how the two interacted with each other.

Over a period of time, scientists maneuvered this pair of satellites from their original Lagrangian point orbits into places closer to the Moon. It’s a very neat re-use of space hardware that otherwise would have been shut down. The THEMIS mission itself is continuing — the other three THEMIS probes continue their original science mission, studying the substorms that are part of its names. These are atmospheric events visible  near Earth’s poles as sudden increases in the brightness of the aurorae. The findings from the mission may help protect commercial satellites and humans in space from the adverse effects of particle radiation.

So, what kind of science will the two diverted ARTEMIS babies do at the Moon?  Given that these spacecraft bear instruments that are sensitive to magnetic fields, they should be able to collect data about the very weak lunar magnetic fields that DO exist, provide information about the  lunar core (which does not appear to be generating a magnetic field), and information about any pockets of magnetism that might exist in the Moon’s crust (outer layer). Essentially, ARTEMIS will probe the Moon’s magnetic environment.  The data it gets will help scientists understand more about the interior structure of the Moon.  This is a very cost-effective way to do further lunar science, and it will be interesting to see what the next five to seven years of ARTEMIS efforts uncover.