As seen by the Hubble telescope in 2003 and 2004.

When NASA’s Dawn mission gets to Ceres on March 6, it’ll be our first up-close look at a dwarf planet. The spacecraft will spend the next year or so orbiting this big rock, snapping photos, scanning its interior, and trying to make sense of how planets form. Scientists don’t really know what we’ll find there. Up until recently, the image at right was our best picture of Ceres.

Click through the gallery below to see what we might find as Ceres comes into focus.


In January 2014, the Herschel telescope spotted plumes of water vapor over Ceres. The observations indicated the dwarf planet spews 13.2 pounds of water from its surface every second, from two different locations. It may be those icy vapors are erupting from cryovolcanoes–volcanoes that discharge frozen materials instead of lava.

An Atmosphere

On Ceres’ surface, ice that sublimates into vapor and material from cryovolcanoes (if they exist) may provide a thin atmosphere around the small planet.


As Dawn draws nearer, two bright spots have shown up on Ceres’ face. Those spots reflect more light than the rest of the planetoid, and scientists aren’t sure why. It may be that an impact uncovered a shiny material there, such as ice. Or, the spots may have a “volcano-like origin.”


“Yes, Ceres may have moons,” Dawn scientist Marc Rayman tells Popular Science. “Although astronomers have looked [at Ceres] with Hubble and with telescopes on the ground, and they have not found any. But it’s certainly possible Ceres has one or more. Dawn will search from its unique vantage point. All we can say now is that if that dwarf planet has any, they must be small. Telescopic searches should have found a moon if its larger than about half a mile or so across.”

An Ocean Beneath The Surface

Although its surface is expected to be cold and icy, Ceres may harbor an ocean below ground. By mapping Ceres’ gravity field, Dawn will shed light on how mass is distributed throughout the planetoid’s core, which will hopefully resolve the question of whether liquid water exists beneath Ceres’ icy mantle.

Fresh Craters

“Fresh craters would provide a direct view of what lies beneath the surface,” says Rayman. If whatever caused these craters happened to uncover a bit of subsurface ice, the team would like to study it before it turns into water vapor and disappears into space.

Hints Of Life

It’s a bit of a long-shot, but astrobiologists think that if Ceres really does harbor a liquid ocean inside, the planetoid could be home to novel lifeforms. If something’s living on Ceres, Dawn probably won’t be able to detect it. But the spacecraft can look for conditions that are favorable to life, helping to inform later missions.

A Planet

In the 200 years since its discovery, Ceres has been categorized variously as a planet, a large asteroid, and a dwarf planet. Its status was again called into question in 2006, when scientists debated Pluto’s planetary identity. The International Astronomical Union decided that in order to be called a ‘planet,’ an object has to have enough gravity to clear everything out of its orbit. Pluto failed the test and so did Ceres, but some scientists are hoping that Ceres’ upcoming close-ups could earn it a promotion back to full planet status.