Before New Horizons blew our minds with its incredible images of Pluto, there was the Dawn spacecraft and Ceres. Dawn will resume normal observations of Ceres later this month, but NASA recently gave us another great look at the mysterious world inside the asteroid belt.
The exact origins of Ceres’ bright spots continue to elude scientists, and Dawn uncovered another intriguing feature of the dwarf planet. A four-mile high mountain shaped like a pyramid.
Dawn science team member Paul Schenk, a geologist at the Lunar and Planetary Institute, described the mountain as “among the tallest features we’ve seen on Ceres to date.”
“It’s unusual that it’s not associated with a crater. Why is it sitting in the middle of nowhere? We don’t know yet, but we may find out with closer observations,” adds Schenk.
Another mystery is its color. Mission Director Marc Rayman touches on this in the video below. One side is dark while the other has bright streak-like features. What is influencing the differences in color? What forces could have created this mountain that juts out from Ceres’ surface? Those are just two of the many questions the Dawn mission team hope to answer as the spacecraft reaches lower orbits.
Ceres bright spot questions continue
The crater where the bright spots call home now has an official name – Occator, a Roman agricultural deity. All of the craters on Ceres are named after gods and goddesses of agriculture and vegetation from world mythology. Check out the names of Ceres’ other craters below.
The Dawn team continues to study the bright spots, but they are no closer to figuring out what they are made of. Ice was the most common theory. Yet, the spots’ albedo, how much light they reflect, is lower than expected if it was ice.
“We are now comparing the spots with the reflective properties of salt, but we are still puzzled by their source. We look forward to new, higher-resolution data from the mission’s next orbital phase,” says Chris Russell, Dawn’s principal investigator.
A pair of interesting large impact basins has also caught the eye of Dawn’s science team. Many cracks extend away from them and scientists hope to better understand the mechanics behind it in subsequent observations.
What’s next for Dawn?
In mid-August, Dawn will reach its next observation orbit at an altitude of 900 miles. The spacecraft will be three times closer to Ceres than it was at its previous orbit. It will stay in this orbit, called High-Altitude Mapping Orbit (HAMO), until mid-October. During the HAMO, Dawn will continue mapping Ceres with its visible and infrared mapping spectrometer (VIR) and its camera.
After finishing the HAMO, Dawn will spend two months flying even closer to Ceres. By late November, the spacecraft will be just 230 miles above the surface of Ceres. Here, it will conduct its low-altitude mapping orbit (LAMO). Using its gamma ray and neutron detector (GRaND), Dawn will uncover what kinds of elements are present on and near Ceres’ surface.
Dawn’s LAMO has a tentative end date of June 30, 2016. After that, Dawn’s mission will come to an end as it runs out of hydrazine fuel.
Are you ready to be blown away by the images of Ceres? The image below was taken on June 25 at an altitude of 2,700 miles.
Looks pretty good, right? Imagine how good the images snapped at an altitude of 900 miles will look. I can’t wait.