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Artist impression of water outgassing from two sources on Ceres.

An artist impression of water outgassing from two sources on Ceres.

ILLUSTRATION BY Y. GOMINET and B. CARRY/CNRS/IMCCE-OBSERVATOIRE DE PARIS  

Dan Vergano

National Geographic

Published January 22, 2014

Water spewing from icy volcanoes or ice patches may adorn our solar system's largest asteroid and smallest dwarf planet, known as Ceres, an international astronomy team says, instantly raising questions about the possibility of life there.

The announcement marks the first sighting of water vapor on Ceres and instantly elevates it into the ranks of the most intriguing objects in the solar system. (See also: "Dwarf Planets.")

Other objects in that elite club include icy worlds like Jupiter's moon Europa and Saturn's moon Enceladus, where signs of water plumes hint at water under an icy surface where alien life might survive. (See: "Could Some Alien Worlds Be More Habitable Than Earth?")

"Ceres is indeed an icy object with the potential of a subsurface ocean," says European Space Agency astronomer Michael Küppers, who led the Nature journal study.

Past observations attempting to confirm indirect hints of water on Ceres had been thwarted by the asteroid's faintness when viewed from Earth, and the detection was "a real surprise, at least to me," Küppers says by email.

Alien Life Potential?

Astronomers have been staring at Ceres since 1801, curious about the tiny world, only 590 miles (950 kilometers) wide, which reigns as the largest object in the solar system's asteroid belt.

Perched between Mars and Jupiter, Ceres resides some 260.4 million miles (419 million kilometers) from the sun, about 2.8 times farther away from our star than Earth is. The new report suggests that at least two locations on its surface spew water vapor into its thin atmosphere.

The team reports that observations made from 2011 to 2013 at the ESA's Herschel Space Observatory picked up signs that Ceres was releasing about 13.2 pounds (6 kilograms) of water per second from its surface into space, originating from two sites near its equator.

"Very exciting news," says Carol Raymond of NASA's Jet Propulsion Laboratory in Pasadena, California.

Raymond is the deputy principal investigator on NASA's Dawn spacecraft, which is headed for an orbital rendezvous with Ceres in 2015. "Ceres now looks like one of the good places in the solar system with astrobiological [alien life] potential," she says.

Comet or Geyser?

The water vapor observations came during a time when Ceres was at its closest point to the sun, an occurrence known as the perihelion, on its 4.6-year-long orbit of the sun, Küppers says.

That timing suggests that the water vapor spewed from ice patches on Ceres's surface, sublimating into space like a comet shedding a tail as it warms on a plunge past the sun.

"It's not an atmosphere like Earth's in that most of the water escapes into space due to Ceres's comparably low gravity. In that respect it is more similar to a comet," Küppers says."I do not expect a stable atmosphere."

Instead of cometlike ice patches, Raymond hopes to see water-spewing geysers (a phenomenon known as "cryo-volcanism") spouting from the asteroid when Dawn arrives at Ceres. That's because Dawn could fly through a geyser plume and analyze its contents.

The spacecraft can't fly through an ice patch.

Dawn is expected to start orbiting Ceres when it will be near its farthest point from the sun on its orbit, the so-called aphelion. If the asteroid is only spewing water when it is closest to the sun, then it may disappoint Dawn's scientists' hopes for a cryo-volcano show.

If there are geysers, the study indicates they aren't strong ones. "The plume would be more like a puff," Raymond says, for Dawn to sail through and collect data on the interior of the asteroid.

Küppers thinks the cometlike ice patch explanation is more likely, explaining past negative results of water vapor observations (a partial observation was made in 1991) made close to aphelion on Ceres.

The asteroid likely lacks an internal dynamo to warm geysers, as well as the tidal stresses that heat the moons, Europa and Enceladus. And Küppers regards the notion of an internal ocean on Ceres as speculation at this point.

"I really expect Ceres is going to be exciting, whatever we find," says Raymond.

In particular, Dawn should closely map the origin sites for the water vapor emissions in the study. While missions for future landers have been proposed for Europa and Enceladus, Raymond also notes that Ceres is much closer to Earth than those moons are.

A recent space travel study by Purdue University engineers, for example, suggested that astronaut travel to Ceres, a two-year trip that would include a 110-day stay on the asteroid, would not pose significantly more challenges than proposed trips to Mars.

And there would be plenty of water to drink when they arrived, apparently.

Asteroid Origins

The heavyweight of the asteroid belt, Ceres is also the smallest dwarf planet in the solar system, according to International Astronomical Union specifications. The other IAU-recognized dwarf planets are Pluto, Eris, Haumea, and Makemake in the inner comet belt beyond Neptune.

Dwarf planets are worlds massive enough for their gravity to pull them into a round shape, like Ceres, but they aren't so big that they have cleared out their orbital region of space of similarly sized competitors.

Caltech astronomer Mike Brown suggests that more than 300 such dwarf planets may reside in the deep space comet belts surrounding the solar system.

The discovery of water vapor on Ceres may point to another connection between comets and dwarf planets, suggest astronomers Humberto Campins

and Christine Comfort of the University of Central Florida in Orlando, in a commentary accompanying the study.

Ceres may simply represent a very large comet nudged closer to the sun by the migration of Jupiter's orbit in the solar system some four billion years ago, they suggest. That would make it a remnant of an era when Earth and the other planets of the solar system suffered fierce bombardments by comets. (See also: "Asteroids and Comets.")

"The 'Ceres is a comet' suggestion fits nicely with the recently discovered active asteroids or main-belt comets," Küppers says. "Those are much smaller objects [ones about a kilometer wide] in the asteroid main belt that show cometlike dust comae or tails."

Follow Dan Vergano on Twitter.

11 comments
Michael Button
Michael Button

I wonder if Ceres collided with mars could it somewhat create a more dense atmosphere, add surface water, and possible life forms?

Michael Button
Michael Button

I wonder if it would be possible to force Ceres to collide with mars to possibly createa Mrs dense atmosphere and surface water?

Amy F.
Amy F.

It's incredible to think that there was/is a possibility that we could live on a different asteroid/ dwarf planet. 

Chris Landau
Chris Landau

I am sure the water vapour is from the north and south poles of Ceres and not from the equatorial regions and its emmission is being driven by its rapid rotation, which is heating its core. The poles will also show the same hexagonal vortex structure located on Jupiter, Saturn, Uranus and Neptune, part of the physical representation of its internal magnetic field. The water vapour is being emitted on the Cerian poles as with Enceladus and Europa from their poles due to their rapid spin and core heating by magnetic flux induction.


With a rotation rate of only 9 hours and a low escape velocity of only 0.5 km/s, I am sure it will be the first base to be settled in our solar system by man. With an abundant water supply and some screening from the solar radiation by its relatively strong magnetic field, it will be a far superior base than Mars or our moon to begin extending our human reach.


My only concern is that, if life is found and it is a strong possibility, we will be eating Cerians, putting them in zoos, paying them minimum wage and polluting their world.


I look forward to the photographic exploration of Ceres by Orbital Sciences Dawn spacecraft next year. Should we be eating plant based Cerian food?


Chris Landau (geologist) 23rd January 2014

David Walmsley
David Walmsley

Sounds like debris from the event that broke Tiamat up 65 million years ago, resulting in the creation of the asteroid belt and Earth's eventual arrival in its present orbit. Earth carried most of Tiamat's water with it, as it travelled through the Void without form, but with darkness upon the face of the deep, tra la.

Mars Ultor
Mars Ultor

If Ceres were to harbor life, it would be very appropriate. Ceres, the Roman goddess of grains, life and fertility harboring life itself. Very exciting news. 

Migx S.
Migx S.

infrared its my name :D

Manju Das
Manju Das

Really amazing pic. in artist's view. Water vapour near CERES. It's moisture. ( Measure by INFRA -RED instrument )

Ask an ecologist.

Didier Newman
Didier Newman

So, perhaps, is there fossils or life elsewhere? But, isn’t the emergence and maintenance of life a process of radical contingency? That is, is a unique and unrepeatable past totally necessary? Or does life emerge through space like mushrooms when some conditions are present? So, how many conditions are necessary: three, four, trillions, infinite? Only one, water or any sort of God? Is God the word that means infinite conditions, absolute necessity? Anyway, how did the life that emerge in a given conditions resist when switching to a different  moment? How does life resist time itself, the effects of entropy? But, is it possible for human beings to recognise a simpler life than their own brain only? On the other hand, beyond likeness, is it possible to recognise a complex life than their brain, is this the extra-terrestrial life that some people are searching unsuccessfully? However, is there an origin of life or would it be as finding a cut in the material history of the universe, an infinite void that human language patches now? Along these lines, there is a peculiar book, a short preview in http://goo.gl/rfVqw6 Just another suggestion, far away from dogmas or axioms.

Khalid Abukalusa
Khalid Abukalusa

@Chris Landau  your interpretation could be right if u could not see clearly that the water vapour was coming out from two locations that have an approximate angle of 45 , ur comment was really amazing though.  

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