Hubble Photographs Two Enormous Asteroids

Since its launch in 1990, the Hubble Space Telescope has contributed enormously to the field of astronomy. Recently, the renowned telescope added to its list of historical importance by using its Wide Field Planetary Camera 2 to photograph two of the largest asteroids known to humans. According to Live Science, this imaging discovery will soon be subjected to more in depth investigations by NASA's Dawn spacecraft.

The first asteroid, named Ceres is spherical in shape, and characteristics show that it closely resembles a planet. Since its discovery in 1801, controversy has surrounded the classification of the asteroid. When it was first discovered, it was put into the group with planets, but then later demoted to an asteroid. The ongoing debate between the classification of the planet Pluto has recently influenced the definition of Ceres, and now is categorized as a dwarf planet. With its width of 590 miles (950 kilometers), Ceres is the size of Texas. Surprisingly, the asteroid represents a vast amount of mass, accounting for up to 30 to 40 percent of all the mass in the asteroid belt between Mars and Jupiter.

The counterpart of Ceres is smaller, but is still of a considerable size at about 330 miles (530 kilometers) wide. Named Vesta, this irregularly shaped mass in the asteroid belt is about the size of Arizona.

After a much delayed mission, NASA's Dawn spacecraft probe will be put into space on July 7th and travel towards the asteroid belt to investigate these two anomalies. Once there, the probe will embark on a five year orbital pattern around the two asteroids, photographing and storing data of Vesta in 2011 and Ceres in 2015.

With the Hubble Telescopes images, astronomers now have the capability to map out Vesta's southern hemisphere and analyze its geographic structure and composition. Color differences in the images suggest different surface chemicals, possibly due to volcanic activity. This will be verified and explored in the near future by NASA's Dawn spacecraft. In the southern hemisphere, astronomers have mapped out an enormous 285 mile (456 kilometer) crater, caused by an ancient collision that threw up many smaller asteroids into the surrounding asteroid belt. Astronomers and researchers of Ceres and Vesta have drawn the analogy that Vesta's surface may parallel the surface of Earth's moon in that the effects might have similar characteristics to the dark "seas" and bright highlands of the moon.

Ceres on the other hand, may closely resemble Earth, in that astronomers hypothesize that the interior of Ceres may suggest a layered crust, rocky core, and icy mantle. The possibility of water located in Ceres is also a bonus that astronomers are willing to investigate with the approaching Dawn spacecraft launch.

Robert Roy Britt. "Hubble Photographs Two Huge Asteroids." Live Science. http://www.livescience.com/space/scienceastronomy/070620_hubble_ceresvesta.html