March 20, 2019

21.10.09:IBEX: The Unsung Hero.

Amidst the recent water on the Moon hoopla, one key player was largely missed by the media; IBEX, NASA’s Interstellar Boundary Explorer. Launched in October 19th, 2008, IBEX travels in a highly eccentric Earth orbit that takes it from a perigee of 4,000 miles to an apogee of 150,000 miles in 3 days. This enables IBEX to dip in and out of Earth’s magnetosphere and bow shock, panning its 7 degree field of view camera in an all sky survey to map the heliopause, the boundary of our solar system with interstellar space. The cameras, dubbed IBEX Hi & Lo respectively, are the most sensitive neutron detectors ever flown, and span the sky looking for particles moving in access of 161,000 miles per hour. When it was first turned on & checked out earlier this year, engineers got a start; a nearby, large source of neutral atoms nearly filling the field of view. That was none other than our own Moon, reflecting the solar wind off of the lunar soil. The Earth’s magnetic field protects us from this onslaught, which hits the daytime side of the Moon unimpeded. The signature and percentage of particles seen lends credence to the water mixed in with the lunar soil theory, embedded mostly as hydroxyl compounds. In fact, the heliopause itself has shown signs of shrinking as of late due to the ongoing solar minimum… the just released image above released by the IBEX team sheds light on the overall structure of the heliopause as our solar system moves through the interstellar medium. Most interestingly, it shows that a large ribbon of Energetic Neutral Atoms (ENA’s) flowing between Voyager 1 & 2, our farthest soon-to-be intergalactic outposts. Just what would life in the interstellar medium be like, should it be pressed down or swept back interior to Earth’s orbit, as has been hypothesized in the distant past? Watch for more news on IBEX to come!