MSX Galaxy Maps Yield Highest Resolution

The Midcourse Space Experiment (MSX) observatory-class satellite delivered mid-infrared maps of the center of our galaxy with a resolution 15 times better than the previous best taken by the Infrared Astronomical Satellite. The image at left is a false-color composite of three separate MSX wavelengths (6 to 11, 11 to 16 and 18 to 26 µm) made from the satellite's Spatial Infrared Imaging Telescope (SPIRIT III). It combined 23 scans over the 1- by 3-degree region of our galaxy to form an image that provides a sense of the differing temperatures; hot objects such as stars show up as blue, while cool objects are red. On the right, an image of the same region was taken from the digitized Palomar Observatory Sky Survey. Here, absorption of visible light by interstellar dust is so great that the galactic center is hidden from view. The MSX was launched in April 1996 from Vandenberg Air Force Base, Calif., to orbit the Earth at an altitude of 561 mi. It is the first demonstration in space of technology used to characterize ballistic missile ignatures during the midcourse flight phase between booster burnout and missile re-entry. The satellite's imaging capabilities support a wide variety of dual-use research involving global atmospheric change, astronomy, and space contamination and debris. Johns Hopkins University Applied Physics Laboratory in Laurel, Md., is conducting the satellite's round-the-clock operations.