There’s been a lot of hubbub lately about habitable planets, but most of the ones we’ve identified so far with the help of the now-defunct Kepler telescope are a bit of a commute — like 20 light years or so. So we might put exoplanets on the back-burner for a little bit and turn our attention to closer dwarf planets. If we ever have to go on an epic journey to destroy an evil ring, this is where we’ll load up on grumbly, bearded warriors to accompany us. And now we have a specific one in mind: Ceres.
Ceres hangs out in the Mars-Jupiter asteroid belt and, while unique, has drawn some comparisons to Europa, Jupiter’s moon, and Enceladus, Saturn’s moon, because of its potential for facilitating life. It was the first discovered dwarf planet — in 1801 it was classified as a planet, but was then downgraded to an asteroid and then upgraded to a dwarf planet. It’s almost 600 miles across, rotates every nine or so hours, and its mass is a tiny fraction of Earth’s (0.015 percent). It’s actually so tiny that it has dual citizenship as a dwarf planet and an asteroid.
NASA’s Dawn spacecraft is in orbit around the asteroid Vesta, and will head to Ceres in March 2015. Dawn’s aim is to gather information about the evolution of the solar system by visiting these two bodies that have been around and intact since the early days of the Milky Way. Britney Schmidt, a scientist from the Dawn Mission team, believes that Ceres might be “a game changer in the solar system” because of the likelihood that ice exists under its clay surface. Like Mars, it may at one time have had an ocean. And it’s close enough to the Sun for the ice to melt and refreeze. Schmidt calls Ceres “the gatekeeper to the history of the water in the middle solar system.”
Using spectral telescopes to examine the light reflecting from Ceres, scientists learned that the clay-like surface on Ceres contains water. They’ve also found indications of carbonates, minerals formed by water and heat, and which are often signs of life. We’ll know more when Dawn gets there.
Dwarf planets have many characteristics of planets — they’re round and they orbit the Sun, but unlike other planets, they lack the gravity to remove smaller objects from its orbit. They’re simply too small to be given planetary status, such as Pluto, which was demoted to dwarf-planet status amid much controversy. Astronomers believe there could be hundreds of dwarf planets in the solar system. As of 2008, the International Astronomical Union officially recognized five dwarf planets, including Ceres and Pluto (the others are Eris, Haumea, and Makemake). Makemake?
Ceres is also the subject of some pretty bold claims that NASA knows it harbors life and that THE ALIENS ARE COMING! One Youtube video even promises that Ceres will merge with Earth in early 2015. Cosmic conspiracy theorists will find plenty of material on Ceres, even if it proves to be alien-free.