For the second time this year and the fifth in the last 13 months, astronomers have identified an asteroid encircled by a satellite. Alex Storrs and the Hubble Space Telescope Asteroid Team found a companion orbiting 107 Camilla, a main-belt asteroid about 220 kilometers across. The discovery was made in a quick succession of HST images taken on March 1st. Although the satellite was seen 1,000 km from Camilla, more observations will be needed before its orbit can be calculated. Storr's team has another HST run scheduled for March 27th. Details appear in IAU Circular 7599.

The discovery of Camilla's companion brings the count of confirmed binary asteroids to seven; another eight or nine are suspected of duplicity, most of which are small near-Earth objects with unusual light curves.

On February 18th, Michael Brown and Jean-Luc Margot (Caltech) went on an asteroid hunt. While observing with the 10-meter Keck II telescope atop Hawaii's Mauna Kea, Brown and Margot took a look at the 130-kilometer-wide asteroid 87 Sylvia. The minor planet, discovered in 1866, is one of the largest asteroids in the solar system.

Using Keck's adaptive-optics system, the two astronomers resolved a small moon orbiting Sylvia. They report that separation between the two bodies appears to be approximately 1,200 km, and based on initial observations, the companion is only 7 km wide.

The discovery is very encouraging for Brown and Margot. "Based on small-number statistics -- finding one in one night -- there might be a lot more out there," says Brown. "Suffice to say we're not done [looking]."

After spending two weeks on the surface of asteroid 433 Eros, the NEAR Shoemaker spacecraft sent a final burst of data to Earth late on February 28th before falling silent. "This mission has been very successful far beyond what was in the original mission plan," comments mission director Robert Farquhar. "When you talk about 'faster, cheaper, better,' this is what 'better' means." During its year in orbit around Eros, the spacecraft relayed 10 times more data to Earth than expected, including some 160,000 images of the 33-kilometer-long asteroid.

The unexpected windfall of surface data, collected in overtime by its gamma-ray spectrometer, far exceed that obtained during an entire year of orbiting the asteroid. Team leader Jacob Trombka (NASA/Goddard Space Flight Center) says the week-long study should eventually yield abundances for iron, silicon, oxygen, and potassium in surface materials to a depth of about 10 centimeters. These data are crucial because measurements from the companion X-ray spectrometer sample only the topmost 0.1 millimeter of the surface. "The iron-to-silicon ratio is critical for classifying the surface material," Trombka says, and the value for potassium (a volatile element easily lost to space during heating) will indicate whether Eros was ever partially molten.

Analysis of the gamma-ray data will take at least several weeks, Trombka cautions. A similar instrument flown aboard Apollos 15 and 16 yielded important compositional findings about the Moon -- but those data required 6 to 8 months to calibrate and analyze. In the mean time, Trombka adds, "We can make some very good guesses" based on what's already known about Eros's composition.

Although NASA will no longer track NEAR Shoemaker, Farquhar hints that we may not have heard the last from this spacecraft. In August 2002 its solar-cell panels will once again be in full sunlight, potentially an opportune time to attempt to awaken the spacecraft from its long, cold hibernation.