Mysterious bright spots inside a crater on a dwarf planet Ceres was spotted when NASA’s Dawn spacecraft pulled into orbit earlier this month. It could be caused by water spewing into space, raising the possibility that there is a potential for life beneath its surface, as is thought to be the case on icy moons around Jupiter and Saturn.
From the side view, the bright spot is still visible, meaning it probably protrudes above the crater.
Andreas Nathues, who is in charge of the mission’s camera, and presented the images yesterday at the Lunar and Planetary Science conference (LPSC) in The Woodlands, Texas said, “What is amazing is you can see this feature while the rim is very likely in front of the line of sight.”
“We believe this could be some kind of outgassing.”
From dusk to dawn, the spot brightens throughout the day and disappears at night. This shows that it could be a gas released results from sun-warmed icy patches, suggesting a comet-like behavior.
However, Natheus said the team needed higher resolution data to confirm its true nature. This won’t begin until after mid-April, when Dawn emerges from the dark side of Ceres.
But Timothy Titus of the US Geological Survey in Flagstaff, Arizona, presented a model that examine where on the surface ice could remain stable over the lifetime. Saying such action could only occur at the poles of the Ceres, not at the equator where the spots are located.
Titus found that ice could only be stable in regions above 40 degrees latitude. This entails that they can’t be comet-like. “The water ice is just not stable at the latitudes that the plumes are supposedly coming from,” Titus says.
Another scientist casts doubt that the plumes are caused by cryovolcanism, in which ice and water are forced out of the surface by processes similar of the volcanic eruption on Earth. But according to David O’Brien of the Planetary Science Institute in Tucson, that Ceres doesn’t have enough internal forces to create such eruptions.
So Ceres could be producing comet-like emissions in this region, driven by a weak cryovolcano. “It’s sort of a midpoint between comets and cryovolcanic icy worlds,” says Titus.
“Any place you’ve got the potential for liquid water, you’ve got the potential for life,” says Titus. “Ceres could be an extremely exciting astrobiological target.”
In conclusion, the talk of the conference is whether Ceres might someday be fit for human habitation.