Fomalhaut's Kuiper Belt But when Paul G. Kalas (University of
California, Berkeley) and two colleagues pointed the Hubble
Space Telescope at Fomalhaut last year, they were in for a huge
surprise. Hoping to detect the feeble glow of orbiting planets,
Kalas instead found a belt of cold dust orbiting far from the
star. The dust comes from small bodies colliding and grinding
themselves down to tiny grains. Kalas and his colleagues
estimate that the belt known as a debris disk contains 50 to 100
Earth masses of material. As Kalas's group reports in the June
23rd Nature, Fomalhaut's belt is analogous to our solar system's
Kuiper Belt (which contains Pluto and nearly a thousand other
known small, icy bodies), but with several important
differences. Fomalhaut's belt is much farther from its star: 133
to 158 astronomical units (1 a.u. is the average Earth-Sun
distance), compared to the 30 to 50 a.u. for our solar system.
Perhaps more important, Fomalhaut's belt is slightly oval, and
the geometric center of the ellipse