Astronomy Picture of the Day

Explanation: What is our universe made of? How rapidly is our universe expanding? When did galaxies form? These questions, among the most important and baffling to astronomers since the beginning of the modern astronomical era, might well be answered by a new space satellite mission. The Microwave Anisotropy Probe (MAP) is being designed inspect the universe's microwave background radiation in more detail then ever before. MAP will record the frequency, size and temperature of bumps 20 times smaller than COBE. Astronomers have computed what bumps would be expected from several models of our universe, and comparing these results to MAP's data may yield a new understanding of the composition and structure of our universe. MAP has just won approval as a NASA MIDEX class satellite, and is currently scheduled to launch in the year 2000.