Author: Robert Zimmerman

At today’s press conference at the 42nd meeting of the AAS Division for Planetary Sciences, the topic was asteroids, including one which holds the possibility of hitting the Earth.

• 65 Cybele has been found to have water ice and organic molecules on its surface, the second such asteroid so found. Key quote from the abstract:
  

  We conclude that 65 Cybele is covered by fine anhydrous silicate grains, with a small amount of water-ice and complex organic solids. This is similar to comets where non-equilibrium phases coexist, e.g. water-ice and anhydrous silicates; thus we conclude that this is a very primitive object.

  According to Humberto Campins of the University of Central Florida, this combination of water and organics could become hospitable to life should some form of energy be added, such as an impact to the asteroid.

• The origin of the asteroid Phaethon, cause of the Geminids meteor shower, has been traced to the Pallas family of asteroids, a family created by the debris thrown out during a crater impact on the large asteroid Pallas. Campins also noted that this proves Phaethon is an asteroid and not a comet, a question that astronomers had been debating beforehand. Read the abstract here.
  

• Asteroid 1999 RQ36, which has a 1 in a 1000 chance hitting the Earth in 2182 and is also the prime target of a proposed NASA sample return mission, has now been determined to be a member of the Polana family of asteroids. This makes 1999 RQ36 a very primitive asteroid from the very beginnings of the solar system. Moreover, this suggests that the Polana family could be the “most important” source of many near Earth asteroids. The abstract can be found here.