Here’s the problem with those bright spots on Ceres: They are not alien signals or artificial lights, so in that environment they’re supposed to be ice or salt (or something like salt) reflecting sunlight. They don’t show up when not on the sunny side of life, but they also appear to be accompanied by vapors rising off the surface of the planet and filling that big crater they’re in.
If they are the result of sunlight reflecting off ice, there’s the tiny problem of sublimation … ice would evaporate too quickly into the vacuum of space (which is pretty much right on top of the surface). So, if it is ice, the spots have to be replenished with more ice … a lot.
One of the latest bits of information about Ceres that supports this hard-to-support theory of ice or “ice rinks” is that bit of vapor rising above the spots and a previous discovery of water vapor plumes above the planet surface.
The famous bright spots at the bottom of Ceres’ Occator crater appear to be sublimating material into space, creating a localized atmosphere within the walls of the 57-mile-wide (92 kilometers) hole in the ground, new observations by NASA’s Dawn spacecraft suggest.
“If you look at a glancing angle, you can see what seems to be haze, and it comes back in a regular pattern,” Dawn principal investigator Christopher Russell, of UCLA, said during a presentation Tuesday (July 21) at the second annual NASA Exploration Science Forum, which took place at the agency’s Ames Research Center in Moffett Field, California.
However, Russell has told us that ice is too simple an answer to this complex problem, see gallery below:
And he told Universe Today:
“I was speaking from less than a handful of images, and the interpretation of the images is disputed by some team members,” Russell said in an email. “I would like the debate to go on internally before we make a pronouncement one way or the other. I of course have my personal opinion, but I am not always right.”
Russell said the ice-vs.-salt debate is continuing. “I originally was an advocate of ice, because of how bright the spots seemed to be,” he said. However, the bright material’s albedo, or reflectivity factor, is about 50 percent – which is less than Russell originally thought. “This could be salt and is unlikely to be ice. I think the team opinion is now more in line with salt,” he said.
Here’s a tweet of that Forum discussion:
"Whateer the cause of the bright spots, Ceres is active today". #nasaames #ceres #sservi http://pic.twitter.com/y718IDloda
— Sidney N. (@snnaka) July 21, 2015
So, salt or ice … salt or ice?
If it’s ice, I owe the guy in the above “answer” gallery a cigar. So, I’m going with salt left behind by evaporating or “sublimating” ice. It’s a combo deal, like a two-for-one. So, he’ll get one and I’ll get one (though I am not allowed to smoke cigars).
Now the good news is that Ceres is closing in on the planet and will point more of its instruments at it from a closer range …
“Dawn is currently spiraling toward its third science orbit, 900 miles (less than 1,500 kilometers) above the surface, or three times closer to Ceres than its previous orbit. The spacecraft will reach this orbit in mid-August and begin taking images and other data again,” the agency reports.
And now for some zoomable eye-candy:
What NASA said:
Colorful new maps of Ceres, based on data from NASA’s Dawn spacecraft, showcase a diverse topography, with height differences between crater bottoms and mountain peaks as great as 9 miles (15 kilometers).
Scientists continue to analyze the latest data from Dawn as the spacecraft makes its way to its third mapping orbit.
“The craters we find on Ceres, in terms of their depth and diameter, are very similar to what we see on Dione and Tethys, two icy satellites of Saturn that are about the same size and density as Ceres. The features are pretty consistent with an ice-rich crust,” said Dawn science team member Paul Schenk, a geologist at the Lunar and Planetary Institute, Houston.
Some of these craters and other features now have official names, inspired by spirits and deities relating to agriculture from a variety of cultures. The International Astronomical Union recently approved a batch of names for features on Ceres.
The newly labeled features include Occator, the mysterious crater containing Ceres’ brightest spots, which has a diameter of about 60 miles (90 kilometers) and a depth of about 2 miles (4 kilometers). Occator is the name of the Roman agriculture deity of harrowing, a method of leveling soil.
A smaller crater with bright material, previously labeled “Spot 1,” is now identified as Haulani, after the Hawaiian plant goddess. Haulani has a diameter of about 20 miles (30 kilometers). Temperature data from Dawn’s visible and infrared mapping spectrometer show that this crater seems to be colder than most of the territory around it.
Jake Ellison can be reached at 206-448-8334 or jakeellison@seattlepi.com. Follow Jake on Twitter at http://twitter.com/Jake_News. Also, swing by and *LIKE* his page on Facebook.
If Google Plus is your thing, check out our science coverage here.
from The Big Science Blog http://ift.tt/1Se5FQK
Here’s the problem with those bright spots on Ceres: They are not alien signals or artificial lights, so in that environment they’re supposed to be ice or salt (or something like salt) reflecting sunlight. They don’t show up when not on the sunny side of life, but they also appear to be accompanied by vapors rising off the surface of the planet and filling that big crater they’re in.
If they are the result of sunlight reflecting off ice, there’s the tiny problem of sublimation … ice would evaporate too quickly into the vacuum of space (which is pretty much right on top of the surface). So, if it is ice, the spots have to be replenished with more ice … a lot.
One of the latest bits of information about Ceres that supports this hard-to-support theory of ice or “ice rinks” is that bit of vapor rising above the spots and a previous discovery of water vapor plumes above the planet surface.
The famous bright spots at the bottom of Ceres’ Occator crater appear to be sublimating material into space, creating a localized atmosphere within the walls of the 57-mile-wide (92 kilometers) hole in the ground, new observations by NASA’s Dawn spacecraft suggest.
“If you look at a glancing angle, you can see what seems to be haze, and it comes back in a regular pattern,” Dawn principal investigator Christopher Russell, of UCLA, said during a presentation Tuesday (July 21) at the second annual NASA Exploration Science Forum, which took place at the agency’s Ames Research Center in Moffett Field, California.
However, Russell has told us that ice is too simple an answer to this complex problem, see gallery below:
And he told Universe Today:
“I was speaking from less than a handful of images, and the interpretation of the images is disputed by some team members,” Russell said in an email. “I would like the debate to go on internally before we make a pronouncement one way or the other. I of course have my personal opinion, but I am not always right.”
Russell said the ice-vs.-salt debate is continuing. “I originally was an advocate of ice, because of how bright the spots seemed to be,” he said. However, the bright material’s albedo, or reflectivity factor, is about 50 percent – which is less than Russell originally thought. “This could be salt and is unlikely to be ice. I think the team opinion is now more in line with salt,” he said.
Here’s a tweet of that Forum discussion:
"Whateer the cause of the bright spots, Ceres is active today". #nasaames #ceres #sservi http://pic.twitter.com/y718IDloda
— Sidney N. (@snnaka) July 21, 2015
So, salt or ice … salt or ice?
If it’s ice, I owe the guy in the above “answer” gallery a cigar. So, I’m going with salt left behind by evaporating or “sublimating” ice. It’s a combo deal, like a two-for-one. So, he’ll get one and I’ll get one (though I am not allowed to smoke cigars).
Now the good news is that Ceres is closing in on the planet and will point more of its instruments at it from a closer range …
“Dawn is currently spiraling toward its third science orbit, 900 miles (less than 1,500 kilometers) above the surface, or three times closer to Ceres than its previous orbit. The spacecraft will reach this orbit in mid-August and begin taking images and other data again,” the agency reports.
And now for some zoomable eye-candy:
What NASA said:
Colorful new maps of Ceres, based on data from NASA’s Dawn spacecraft, showcase a diverse topography, with height differences between crater bottoms and mountain peaks as great as 9 miles (15 kilometers).
Scientists continue to analyze the latest data from Dawn as the spacecraft makes its way to its third mapping orbit.
“The craters we find on Ceres, in terms of their depth and diameter, are very similar to what we see on Dione and Tethys, two icy satellites of Saturn that are about the same size and density as Ceres. The features are pretty consistent with an ice-rich crust,” said Dawn science team member Paul Schenk, a geologist at the Lunar and Planetary Institute, Houston.
Some of these craters and other features now have official names, inspired by spirits and deities relating to agriculture from a variety of cultures. The International Astronomical Union recently approved a batch of names for features on Ceres.
The newly labeled features include Occator, the mysterious crater containing Ceres’ brightest spots, which has a diameter of about 60 miles (90 kilometers) and a depth of about 2 miles (4 kilometers). Occator is the name of the Roman agriculture deity of harrowing, a method of leveling soil.
A smaller crater with bright material, previously labeled “Spot 1,” is now identified as Haulani, after the Hawaiian plant goddess. Haulani has a diameter of about 20 miles (30 kilometers). Temperature data from Dawn’s visible and infrared mapping spectrometer show that this crater seems to be colder than most of the territory around it.
Jake Ellison can be reached at 206-448-8334 or jakeellison@seattlepi.com. Follow Jake on Twitter at http://twitter.com/Jake_News. Also, swing by and *LIKE* his page on Facebook.
If Google Plus is your thing, check out our science coverage here.
from The Big Science Blog http://ift.tt/1Se5FQK
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