Year after year, NASA continues to rack up amazing discoveries with its vast assortment of missions. However, even as the U.S. agency wrestles with trying to build its next-generation space ferry amid ballooning project deficits, other nations are making space-exploration gains as well.
Take, for example, a little-known Japanese mission called Akari. Launched in early 2006, Akari (known as "Astro F" during its development) conducted an all-sky survey over the broad infrared wavelength range of 1.7 to 180 microns. Before its coolant ran out in August 2007, Akari produced an all-sky survey more detailed and sensitive than that made by the Infrared Astronomical Satellite (IRAS) in 1983. Scientists from Japan's Institute of Space and Aeronautical Sciences unveiled a catalog of infrared objects just last week.During its prime mission, Akari also spent time studying specific targets, among them the red supergiant star Betelgeuse in Orion. IRAS observations discovered, more than a decade ago, that Betelgeuse creates a shock wave as it moves through the surrounding interstellar "cloud" of gas and dust. Now a team of scientists has used Akari's infrared imagery to reveal the shock front in more detail.
Toshiya Ueta (University of Denver), Hideyuki Izumiura (Okayama Astrophysical Observatory), Issei Yamamura (ISAS/JAXA) and their team report that Betelgeuse is plowing along at 20 miles (30 km) per second through an interstellar flow that originates in Orion's Belt. Meanwhile, a prodigious "wind" of matter is racing outward from the star about half as fast.
The resulting clash of these flows is a shock front about 3 light-years across. That corresponds to about 30 arcminutes — the size of the full Moon — at Betelgeuse's distance of roughly 640 light-years. So it would be visible to the unaided eye if we had infrared vision and Earth's atmosphere allowed these long wavelengths to reach the ground.