NASA’s Dawn Probe Closes In on Ceres


Launched on September 27, 2007, from Florida, NASA’s Dawn mission is finally closing on Ceres, a dwarf planet. Expected to be captured by its gravity on Friday, much-awaited dawn finally arrives after the years of night for NASA.

The early pictures of the Ceres taken by the Dawn have brought to the fore two bright white spots. While, the spots are in a 92 kilometer crater, the one in the center of the crater is about twice as bright as the spot on the side of the crater. Dawn’s deputy principal investigator, Raymond is elated with the endless possibilities that the dwarf planet has to offer. “Ceres has really surprised us,” he said. “The first images have produced some really puzzling features. These spots were extremely surprising to the team, and they have been puzzling to the team and to everybody who’s seen them. This extreme brightness was really unexpected, really, really excited about this feature because it is unique in the solar system.”

Ceres has been known to have heaps of oddities. The scientists are amazed at the roundness of the dwarf planet. One of the most important characteristics of a planet has always revolved around how round it is. Initially assumed to be a planet, Ceres was demoted to being an asteroid since the 19th century astronomers failed to be certain about its shape. However, it was categorized as a dwarf planet way back in 2006, a time when the category was created. According to the International Astronomical Union, “a dwarf planet is similar to the eight main planets (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune) except it has a lot of other stuff orbiting with it around the sun.” The IAU has recognized five dwarf planets: Eris, Pluto, Ceres, Makemake and Haumea, so far.

Having taken photographs of the brighter side of the solar system’s largest asteroid and the smallest known dwarf planet, Dawn has switched over to the dark side in order to enter into orbit. Dawn project manager, Robert Mase said, “We’re going to have a blackout for the next month, until we get back over toward the lit side. But then the floodgates are really going to open when we get to our first science orbit in late April.”

Though Pluto and Ceres are, both, called dwarf planets yet there anything but similar. According to Raymond, “Pluto is thought to have a rocky core and an icy shell, but Ceres is more complex. It probably had a subsurface ocean of liquid water at some point. Scientists believe that ocean has now frozen into solid ice, covered by a crust of rock, dust and debris.”  As per European Space Agency’s Herschel telescope had detected emissions of water vapor from the dwarf planet. There is, therefore, a well-founded speculation that revolves around the possibility of life on Ceres.

As the Dawn arrives at the Ceres, scientists are eager to delve deep into an array of questions. Could Ceres have, ever, fostered life? Does a layer of ice (that was once an ocean) lie just beneath the surface? What is causing those enigmatic bright spots to shine inside a crater on the Ceres?

Sangeeta Purkayastha

Image Source: The Viewspaper