After spending weeks in the (literal) shadow of a giant rock, NASA's Dawn spacecraft is finally getting its day in the sun. On April 10, the eight-foot long probe, originally launched in September 2007, managed to snap some of its most exciting close-up images yet: as it rounded the sunlit side of the dwarf planet Ceres, Dawn photographed its north pole for the first time, revealing a pock-marked, grainy surface not unlike Earth's own moon. Although mission scientists are still wrapped up investigating those previously glimpsed bright spots on the surface of the planet, as the probe draws closer in the coming months, it's likely these north pole images will be only the first in a series of astounding discoveries — but for now, it's an exciting start.
The new images of Ceres' north pole are the highest resolution images captured so far, according to a statement by NASA Jet Propulsion Laboratory officials on Thursday. Taken from a distance of 21,000 miles (or 33,000 kilometers) away, astronomers expect that subsequent images will only improve.
"We have much to do over the next year and a half," said Dawn's principal investigator Chris Russell in a press release back in March when the probe first entered Ceres' orbit, "but we are now on station with ample reserves, and a robust plan to obtain our science objectives."
Of the mysterious bright spots, Russell explained in an email to Bustle on Friday that "vents allowing water vapor or dust being carried by that vapor might be seen as scattered light" as one looked into the direction of the sun. "This is much like the light scattered from your windshield as you drive toward [sunlight]," he said. "In such conditions, you can see every speck of dust on your window." Russell said the team was anxiously awaiting higher resolution snapshots to understand the spots more clearly.
Upon entering orbit around the asteroid belt object on March 6, Dawn became the first spacecraft in history to circle a dwarf planet, after spending 14 months in orbit around the giant rocky asteroid Vesta in 2011 and 2012. "Dawn has the distinction of being the only spacecraft to orbit two extraterrestrial targets," said a JPL spokesperson on Thursday.
Scientists are scheduled to begin closer investigations after May 9, during which they hope to find out whether Ceres, which spans around 590 miles in diameter, contains liquid water beneath its stubbled surface. In a statement on Monday, Russell explained that recent images of the planet's colorful surface suggest that it was once "very much alive".
"This dwarf planet was not just an inert rock throughout its history," said Russell. "It was active, with processes that resulted in different materials in different regions."
The possibility of liquid water somewhere on Ceres was still being considered, Russell explained to Bustle:
We are very sure Ceres has lots of water ... But we're not so sure how that water is stored. The size of [the planet] is known well, as is its mass. ... From that, we [can] obtain a density of two, where water has a density of one and rock about 3.5. A mixture of water and rock explains that density quite well. But like on earth, water can be in the rock (as ice), or it can be in liquid forms. ... Our plan is to search the surface carefully to see if there is evidence for liquid water that was once flowing on the surface, or as geysers or plumes.
Ceres was first formed while our solar system was at a very young age (hence the mission's name, "Dawn"), giving it the distinction of not only being one of our oldest, relatively unexplored neighbors, but the honor of harboring potentially explosive new data in regards to the creation of our own planet as well.
Meanwhile, the peculiar bright spots captured earlier this year continue to baffle mission scientists. "The bright spots continue to fascinate the science team, but we will have to wait until we get closer and are able to resolve them before we can determine their source," explained Russell on Monday, indicating that at least two of the glimmering flecks are located within a crater some 57-miles wide.
On Friday, Russell elaborated on the team's excitement over the newest developments to Bustle:
The team is excited about the new pictures. Ceres has [kept] herself hidden from us in ways other celestial bodies have not. With Vesta and the other large bodies in the asteroid belts, we have meteorites; these bits of rock enable us to determine what the bodies are made of. We have no such evidence from Ceres, which is a mystery in itself.
We're frustrated by the wait to get the resolution needed to resolve [all of our questions], but we will get them. Our orbit plan takes us increasingly close to the surface, so we can see structure about 150 feet across in the final [trajectory].
The next 14 months of study should prove to be exciting ones, if the discoveries already made are any indication — and before the end of its mission in June 2016 (when fuel runs out), planetary enthusiasts and astronomers alike should have plenty of captivating imagery on their plates.