Every day the headlines report the ‘best ever view’ of the dwarf planet Ceres and every day the headlines are true. That will continue to be the case until, at the very least, March 6 when the Dawn Spacecraft is pulled into Ceres orbit.
The most recent best ever images, were taken February 12 at a distance of 52,000 miles from the dwarf planet. While these may be the closest images we’ve ever seen of the dwarf planet, for the moment they are raising more questions than they are answering.
“As we slowly approach the stage, our eyes transfixed on Ceres and her planetary dance, we find she has beguiled us but left us none the wiser. We expected to be surprised; we did not expect to be this puzzled,” said Chris Russell, principal investigator of the Dawn mission, based at UCLA in a statement.
The images being returned by Dawn currently have a resolution of 4.9 (7.8 kilometers) per pixel. They reveal a surface deeply scarred by craters but they are not sufficient yet to explain the mysterious white spots on Ceres.
Although Dawn is getting closer every day, there is no explanation being offered yet for the white spots and those strange reflective areas are just one of the many mysteries which researchers hope to solve.
For one thing, the size and composition of Ceres are very different from other objects seen in the asteroid belt between Mars and Jupiter. Based on what is known about the outer solar system, it seems to have more in common with a Kuiper belt object like Pluto according to William McKinnon, a planetary scientist at the Washington University in St. Louis.
“Ceres, if you look at it, is kind of like a junior version of a Kuiper Belt object. It has the same density. The question is, where did it actually form? Was there enough ice in the primordial asteroid belt to build such a world,” McKinnon said to National Geographic in January.
In January of 2014, streams of water vapor were also seen erupting from two locations on Ceres.
“This is the first time that water has been detected in the asteroid belt, and provides proof that Ceres has an icy surface and an atmosphere,” says Michael Küppers of ESA’s European Space Astronomy Centre in Spain, at the time.
So, probable ice, possible liquid water, the possibility of an atmosphere, it’s unusual composition and those reflective spots are just a few of the questions waiting for answers when Dawn finally arrives.
The Dawn spacecraft spent 14 months exploring the giant asteroid Vesta in 2011 and 2012 before moving on the Ceres. When it arrives it will become the first spacecraft to ever orbit two different targets.
Dawn’s arrival at Ceres combined with the New Horizons spacecraft’s anticipated flyby of Pluto and Charon later this year have led the Planetary Society to call 2015 “the Year of the Dwarf Planet”.
“I’m calling on you, dear readers, to start spreading the word about how awesome 2015 is going to be. How we’re boldly going where no one has gone before. That in February or March of 2015, three tiny dots will start growing into disks on the main viewer of two of our ships — except it’s better than that; it’s not just a privileged ship’s crew that will be seeing these dots grow into worlds, it’s all of us, everyone on Earth, because they’ll be sharing their photos on the Internet, where everyone can see them, and wonder at them, and share them, and talk about them with each other,” said Emily Lakdawalla on the Planetary Society blog.
The most recent images of Ceres can be found at the Dawn mission’s multimedia site, which also features audio, video and interactive media as well as opportunities to participate in Google hangouts with NASA staff.
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