An unexpected mountain has been discovered on Ceres in images sent by NASA's Dawn orbiter:
One year ago, on March 6, 2015, NASA's Dawn spacecraft slid gently into orbit around Ceres, the largest body in the asteroid belt between Mars and Jupiter. Since then, the spacecraft has delivered a wealth of images and other data that open an exciting new window to the previously unexplored dwarf planet.
"Ceres has defied our expectations and surprised us in many ways, thanks to a year's worth of data from Dawn. We are hard at work on the mysteries the spacecraft has presented to us," said Carol Raymond, deputy principal investigator for the mission, based at NASA's Jet Propulsion Laboratory, Pasadena, California.
Among Ceres' most enigmatic features is a tall mountain the Dawn team named Ahuna Mons. This mountain appeared as a small, bright-sided bump on the surface as early as February 2015 from a distance of 29,000 miles (46,000 kilometers), before Dawn was captured into orbit. As Dawn circled Ceres at increasingly lower altitudes, the shape of this mysterious feature began to come into focus. From afar, Ahuna Mons looked to be pyramid-shaped, but upon closer inspection, it is best described as a dome with smooth, steep walls.
Dawn's latest images of Ahuna Mons, taken 120 times closer than in February 2015, reveal that this mountain has a lot of bright material on some of its slopes, and less on others. On its steepest side, it is about 3 miles (5 kilometers) high. The mountain has an average overall height of 2.5 miles (4 kilometers). It rises higher than Washington's Mount Rainier and California's Mount Whitney. Scientists are beginning to identify other features on Ceres that could be similar in nature to Ahuna Mons, but none is as tall and well-defined as this mountain.
"No one expected a mountain on Ceres, especially one like Ahuna Mons," said Chris Russell, Dawn's principal investigator at the University of California, Los Angeles. "We still do not have a satisfactory model to explain how it formed."
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NASA's Dawn Mission to Asteroid Belt Comes to End
NASA's Dawn spacecraft has gone silent, ending a historic mission that studied time capsules from the solar system's earliest chapter.
Dawn missed scheduled communications sessions with NASA's Deep Space Network on Wednesday, Oct. 31, and Thursday, Nov. 1. After the flight team eliminated other possible causes for the missed communications, mission managers concluded that the spacecraft finally ran out of hydrazine, the fuel that enables the spacecraft to control its pointing. Dawn can no longer keep its antennae trained on Earth to communicate with mission control or turn its solar panels to the Sun to recharge.
The Dawn spacecraft launched 11 years ago to visit the two largest objects in the main asteroid belt. Currently, it's in orbit around the dwarf planet Ceres, where it will remain for decades.
Also at Ars Technica, The Verge, and Science News.
Previously: NASA's Dawn Spacecraft Nears the End of its Mission
NASA Retires the Kepler Space Telescope after It Runs Out of Hydrazine
Related:
Pluto and Ceres
After Eight Years, NASA's Dawn Probe Brings Dwarf Planet Ceres Into Closest Focus
NASA's Dawn Orbiter Finds a Mountain on Ceres
Dawn Spies Magnesium Sulphate and Possible Geological Activity on Ceres
Ceres' Cryovolcano Ahuna Mons Formed in the Geologically Recent Past
Ceres's Cryovolcanoes Viscously Relax Into Nothingness
Organic Molecules Found on Ceres
Early Asteroids May Have Been Made of Mud Rather Than Rock
Dawn Mission Extended at Ceres
Ceres May Have Had a Global Surface Ocean in the Past
Bright Areas on Ceres Suggest Geologic Activity
Dawn's Orbit Around Ceres: A New Low
Dawn's Orbit Around Ceres: First Images
Dawn Spacecraft Captures Closest-Ever Images of Ceres' Shiny Occator Crater
Bright Areas on Ceres Suggest Geologic Activity
Since Dawn arrived in orbit at Ceres in March 2015, scientists have located more than 300 bright areas on Ceres. A new study in the journal Icarus, led by Nathan Stein, a doctoral researcher at Caltech in Pasadena, California, divides Ceres' features into four categories.
The first group of bright spots contains the most reflective material on Ceres, which is found on crater floors. The most iconic examples are in Occator Crater, which hosts two prominent bright areas. Cerealia Facula, in the center of the crater, consists of bright material covering a 6-mile-wide (10-kilometer-wide) pit, within which sits a small dome. East of the center is a collection of slightly less reflective and more diffuse features called Vinalia Faculae. All the bright material in Occator Crater is made of salt-rich material, which was likely once mixed in water. Although Cerealia Facula is the brightest area on all of Ceres, it would resemble dirty snow to the human eye.
More commonly, in the second category, bright material is found on the rims of craters, streaking down toward the floors. Impacting bodies likely exposed bright material that was already in the subsurface or had formed in a previous impact event.
Separately, in the third category, bright material can be found in the material ejected when craters were formed.
The mountain Ahuna Mons gets its own fourth category -- the one instance on Ceres where bright material is unaffiliated with any impact crater. This likely cryovolcano, a volcano formed by the gradual accumulation of thick, slowly flowing icy materials, has prominent bright streaks on its flanks.
Ceres and cryovolcanos.
The formation and evolution of bright spots on Ceres (open, DOI: 10.1016/j.icarus.2017.10.014) (DX)
Previously: A Closer Look At Mystery Spots On Dwarf Planet Ceres
NASA's Dawn Orbiter Finds a Mountain on Ceres
Ceres's Cryovolcanoes Viscously Relax Into Nothingness
Organic Molecules Found on Ceres
Dawn Mission Extended at Ceres
Ceres May Have Had a Global Surface Ocean in the Past
(Score: 1, Funny) by Anonymous Coward on Wednesday March 09 2016, @09:23PM
(Score: 0) by Anonymous Coward on Thursday March 10 2016, @12:28AM
Ceriously?
(Score: 3, Interesting) by MrGuy on Wednesday March 09 2016, @09:32PM
So, what you're saying is that it's chief weapon is surprise?
(Score: 3, Informative) by Gaaark on Wednesday March 09 2016, @10:16PM
surprise and fear!
--- Please remind me if I haven't been civil to you: I'm channeling MDC. ---Gaaark 2.0 ---
(Score: 3, Insightful) by fido_dogstoyevsky on Thursday March 10 2016, @12:34AM
And a fanatical devotion to NASA!
It's NOT a conspiracy... it's a plot.
(Score: 1, Offtopic) by archfeld on Thursday March 10 2016, @01:39AM
Is it a big comfy mountain with soft cushions ?
For the NSA : Explosives, guns, assassination, conspiracy, primers, detonators, initiators, main charge, nuclear charge
(Score: 0) by Anonymous Coward on Monday March 14 2016, @03:24AM
Message for you sire; I guess all Flying Circus Spanish Inquisition lines are not equal...
(Score: 3, Interesting) by Zz9zZ on Wednesday March 09 2016, @10:21PM
The crater is slightly elongated in the direction of the mountain, and the mountain looks like it would fit pretty neatly inside the crater. Perhaps an asteroid impacted at relatively low speed, did a small bounce, and landed next to the crater.
~Tilting at windmills~
(Score: 2) by bob_super on Wednesday March 09 2016, @11:37PM
Whether they are directly related or not, they nicely form an explanation: Get hit fast -> crater. Get hit very slow -> mountain.
Given the "aggregate lumps of rocks flying nearby" process of formation of planets, I'm still confused as to why Pluto and Ceres WOULDN'T have mountains.
On a big planet with lots of gravity and a molten phase, I can see that mountains would be hard at formation time, until it hardens a bit and tectonics create them. But on a dwarf body floating in a sea of asteroids?
(Score: -1, Offtopic) by Anonymous Coward on Wednesday March 09 2016, @11:53PM
+3 Interesting!
But mention possibility of electrical deposition acting on this body and it's -1 Troll for you!
(Score: 2) by Zz9zZ on Thursday March 10 2016, @12:01AM
Can you provide a link to a similar claim? I know about electrical deposition for industrial purposes, never heard of it as an "out there" explanation for weird phenomena.
~Tilting at windmills~
(Score: 0) by Anonymous Coward on Thursday March 10 2016, @07:02AM
Trust me, you do not want to know about the "electrical hypothesis". I mean, they laughed at Werner von Braun! They laughed at Einstein! They laughed at Jim Carey! So our completely insane theory about electricity (straight out the Nineteenth Century!!) creating craters and planets and such must be true!! Right? Hello? Guys?? You said there would be Snipe!
(Score: 0) by Anonymous Coward on Thursday March 10 2016, @04:09PM
I know about electrical deposition for industrial purposes, never heard of it as an "out there" explanation for weird phenomena.
What a shame. It's not your fault, the explanations and experimental evidence are actively ignored for some strange (unscientific) reason. Isn't it odd how "ancient aliens" will air on TV, but never the electrical hypothesis for crater formation.
A similar form as Razorback Canyons [nasa.gov] seen on Mars and have been created in the lab via electrostatic discharge. Electrostatic differential after a "carving" discharge causes its charged dust to repel from the crater/canyon and collect at the nearest point of the opposing charge (the crater walls). Nearly all celestial bodies have a statistically unexplainable set of craters within craters (bullseye craters, unlikely to have formed by successive impacts): When lightning strikes it is observed that the secondary and successive pulses along the same ionized path of the original strike creates a pit in the center. Domes in the center of craters are created by discharge going the other direction (deposition). All these phenomena are visible on Ceres, Mars, the Moon, and even Mar's Moons and other Asteroids (which aren't dirty snowballs but oddly shaped rocky bodies that seem to be fused somehow -- perhaps via plasma discharge).
The only theory of such events that is actually backed by experimental evidence is the electrical hypothesis: The sun emits hydrogen ions (protons), and this creates an electrical gradient in the solar system in approximate shape of the inverse square law (same distribution rules as light and other particles). Things further from the sun come barreling in from a more negatively charged environment into a more positively charged region of space, and we see arcing, glowing comet tails (similar phenomenon as the Aurora Borealis), and etc electrical events. Evidence of electrical "machining" is heavily prominent on Ceres, as it lacks the gravity to pull impacting bodies into alignment with itself, yet there are very few craters that are oblong -- The "strikes" overwhelmingly occur directly in line with the center of Ceres. Plasma discharges happen perpendicular to the surface they strike...
Mars. [youtube.com]
Ceres. [youtube.com] Hint: Those off-the-chart bright spots are electrical arcing, we've seen the same over-saturated bright spots on comets... which "inexplicably" glow in UV (which is produced by electrical phenomena).
Comets. [youtube.com]
Rosetta Mission [youtube.com]
It's a travesty, really. Tesla was right all along. How stupid would astronomers appear if they had to throw out most of their theories because they ignored the electical properties of our universe? The EM field is confirmed to be much stronger than gravity, and yet... they ignore electrical forces that work at interplanetary and cosmic scales. I'm hoping it's just hubris and not some more nefarious plot that keeps such things out of the public's mind.
(Score: 2) by Absolutely.Geek on Thursday March 10 2016, @03:51AM
WTF does this mean; I hate this kind of notation as it makes no sense. Is it 46000 x 120 = 5520000km closer? Or is it 46000/120? = 383km ~0.8% of the distance. Why quote a real distance then not a real distance.
As another gripe taken 120 times closer = 22 characters; taken from 383km = 16 characters. The second way is shorter and more clear in its meaning.
Don't trust the police or the government - Shihad: My mind's sedate.