Scientists just got the first close-up look at some perplexing white spots in space, and they're more mystified than ever
Last March, NASA's Dawn spacecraft made history when it became the first mission to ever orbit a dwarf planet.
Before Dawn, the best images we had of the dwarf planet Ceres were taken by the Hubble Space Telescope in the early 2000s from a distance of 257 million miles away. And about the only thing these fuzzy photos were good for was to spark one of the most outstanding questions in astronomy today: What is that bright, white dot?
Ever since Dawn began orbiting Ceres, it has been flying increasingly closer to the surface. That means every new image Dawn transmits to Earth is even more detailed and better than the last. And one of it's greatest contributions yet has been to show us that Ceres doesn't just have one spot: It has many!Shown below are some of Dawn's first close-up shots of Ceres taken last March, snapped from 8,700 miles above the planet's surface:
Check out this incredible shot that Dawn took from 2,700 miles above Ceres' surface - 6,000 miles closer than the images shown above. This is the closest photo we have yet of the mysterious white spots on Ceres:
But even with this level of detail, scientists still can't say for certain what the shiny speckles might be."The bright spots in this configuration make Ceres unique from anything we've seen before in the solar system. The science team is working to understand their source," Chris Russell, principal investigator for the Dawn mission, said in a NASA statement about the latest Dawn images. "Reflection from ice is the leading candidate in my mind, but the team continues to consider alternate possibilities, such as salt."
Other possibilities include some bizarre type of volcanic or geyser activity. Whether the answer is any one of these, however, is anyone's guess at this point. And there's always the chance it's something scientists haven't even considered.
June 6 marked the start of Dawn's first intense survey of Ceres. Over the course of this month, the spacecraft will use some of its instruments to generate a global map of this tiny, crater-ridden world before it spirals even closer - 900 miles above the surface - in August.
Also check out this amazing computer-animated overview of Ceres generated from the thousands of image that Dawn has collected so far: