NASA Plans Search for Alien Life on Ceres, the Mysterious Dwarf Planet

The Dawn spacecraft has spotted bright spots on Ceres's surface it wants to investigate more closely. NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Ceres is a strange place and NASA has learned through its Dawn mission that the dwarf planet could be much more habitable than scientists had ever guessed. Now the space agency plans to probe Ceres even further by sending the Dawn spacecraft closer than ever to its mysterious surface.

The Dawn mission launched a decade ago and was meant to wrap up its work two and a half years ago. But the spacecraft is still working and still has fuel, and scientists are determined to get all the information they can from it, especially now that we know so much more about its target than we did at launch.

Ceres is the only object in the asteroid belt, between Mars and Jupiter, large enough to be classified as a dwarf planet. The team behind Dawn had expected to find a sort of time capsule from the formation of the solar system. But since the spacecraft arrived, scientists have spotted some evidence for lost water on the planet and for geological activity.

"We believe these bright spots are signs that Ceres may have once had a global ocean and so we're very excited about that," Lynnae Quick, a planetary geologist at the Smithsonian Institution, said during a press briefing at last week's annual conference of the American Geophysical Union.

"We believe what has happened [at some of these sites] in the past may be similar to what could be happening today, albeit at a larger scale on some of the active icy moons in the outer solar system," Quick added. Those are places like Jupiter's moon Europa or Saturn's moon Enceladus, which scientists think are some of the most promising candidates for extraterrestrial life.

So the Dawn team is giving their spacecraft one last assignment: To sneak even closer to the surface of Ceres—within a mere 20 miles—for a better look. "We're going to be using an elliptical orbit to dive closer to the surface than we have before," Carol Raymond, one of the NASA scientists leading the Dawn mission, said during the same press briefing.

Read more: Venus Is More Like Earth Than We Thought Despite Nightmare Atmosphere

She added that it's difficult to tell right now precisely how long that will last, since the team isn't positive how much fuel Dawn has left or how quickly it will be used up by the maneuvers. But the spacecraft will likely begin to move closer to the dwarf planet this spring and spend three or four months on its new path before running out of juice.

Of course, even if there's not the faintest trace of life to be found on Ceres, Dawn's final months will still aim to answer some incredibly intriguing questions—and raise others. In particular, the scientists want to use the time to study the surface chemistry and to better understand the dwarf planet's magnetism and volcanism.