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Solar System: 10 Things to Know This Week

Every day, our spacecraft and people are exploring the solar system. Both the public and the private sectors are contributing to the quest. For example, here are ten things happening just this week:

1. We deliver. 

The commercial space company Orbital ATK is targeting Saturday, Nov. 11 for the launch of its Cygnus spacecraft on an Antares rocket from Wallops Flight Facility in Wallops Island, Virginia. Cygnus is launching on a resupply mission to the International Space Station, carrying cargo and scientific experiments to the six people currently living on the microgravity laboratory. 

2. See for yourself. 

Social media users are invited to register to attend another launch in person, this one of a SpaceX Falcon 9 rocket carrying the Dragon spacecraft from Cape Canaveral Air Force Station in Florida. This launch, currently targeted for no earlier than December, will be the next commercial cargo resupply mission to the International Space Station. The deadline to apply is Nov. 7. Apply HERE.

3. Who doesn’t like to gaze at the Moon?

Our Lunar Reconnaissance Orbiter (LRO) sure does—and from very close range. This robotic spacecraft has been orbiting Earth’s companion since 2009, returning views of the lunar surface that are so sharp they show the footpaths made by Apollo astronauts. Learn more about LRO and the entire history of lunar exploration at NASA’s newly-updated, expanded Moon site: moon.nasa.gov

4. Meanwhile at Mars…

Another sharp-eyed robotic spacecraft has just delivered a fresh batch of equally detailed images. Our Mars Reconnaissance Orbiter (MRO) surveys the Red Planet’s surface daily, and you can see the very latest pictures of those exotic landscapes HERE. We currently operate five—count ‘em, five—active missions at Mars, with another (the InSight lander) launching next year. Track them all at: mars.nasa.gov.

5. Always curious. 

One of those missions is the Curiosity rover. It’s currently climbing a rocky highland dubbed Vera Rubin Ridge, turning its full array of instruments on the intriguing geology there. Using those instruments, Curiosity can see things you and I can’t.

6. A new Dawn. 

Our voyage to the asteroid belt has a new lease on life. The Dawn spacecraft recently received a mission extension to continue exploring the dwarf planet Ceres. This is exciting because minerals containing water are widespread on Ceres, suggesting it may have had a global ocean in the past. What became of that ocean? Could Ceres still have liquid today? Ongoing studies from Dawn could shed light on these questions.

7. There are eyes everywhere. 

When our Mars Pathfinder touched down in 1997, it had five cameras: two on a mast that popped up from the lander, and three on the rover, Sojourner. Since then, photo sensors that were improved by the space program have shrunk in size, increased in quality and are now carried in every cellphone. That same evolution has returned to space. Our Mars 2020 mission will have more “eyes” than any rover before it: a grand total of 23, to create sweeping panoramas, reveal obstacles, study the atmosphere, and assist science instruments.

8. Voyage to a hidden ocean.

One of the most intriguing destinations in the solar system is Jupiter’s moon Europa, which hides a global ocean of liquid water beneath its icy shell. Our Europa Clipper mission sets sail in the 2020s to take a closer look than we’ve ever had before. You can explore Europa, too: europa.nasa.gov

9. Flight of the mockingbird. 

On Nov. 10, the main belt asteroid 19482 Harperlee, named for the legendary author of To Kill a Mockingbird, makes its closest approach to Earth during the asteroid’s orbit around the Sun. Details HERE. Learn more about asteroids HERE. Meanwhile, our OSIRIS-REx mission is now cruising toward another tiny, rocky world called Bennu.

10. What else is up this month? 

For sky watchers, there will be a pre-dawn pairing of Jupiter and Venus, the Moon will shine near some star clusters, and there will be meteor activity all month long. Catch our monthly video blog for stargazers HERE.

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Flight Over Dwarf Planet Ceres

Take a flight over dwarf planet Ceres in this video made with images from NASA’s Dawn spacecraft. The simulated flyover was made by the mission’s camera team at Germany’s national aeronautics and space research center (DLR).

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NEW RESEARCH SHOWS CERES MAY HAVE VANISHING ICE VOLCANOES

A recently discovered solitary ice volcano on the dwarf planet Ceres may have some hidden older siblings, say scientists who have tested a likely way such mountains of icy rock – called cryovolcanoes – might disappear over millions of years.

NASA’s Dawn spacecraft discovered Ceres’s 4-kilometer (2.5-mile) tall Ahuna Mons cryovolcano in 2015. Other icy worlds in our solar system, like Pluto, Europa, Triton, Charon and Titan, may also have cryovolcanoes, but Ahuna Mons is conspicuously alone on Ceres. The dwarf planet, with an orbit between Mars and Jupiter, also lies far closer to the Sun than other planetary bodies where cryovolcanoes have been found.

Now, scientists show there may have been cryovolcanoes other than Ahuna Mons on Ceres millions or billions of years ago, but these cryovolcanoes may have flattened out over time and become indistinguishable from the planet’s surface. They report their findings in a new paper accepted for publication in Geophysical Research Letters, a journal of the American Geophysical Union.

“We think we have a very good case that there have been lots of cryovolcanoes on Ceres but they have deformed,” said Michael Sori of the Lunar and Planetary Laboratory at the University of Arizona in Tucson, and lead author of the new paper.

Ahuna Mons is a prominent feature on Ceres, rising to about half the height of Mount Everest. Its solitary existence has puzzled scientists since they spied it.

“Imagine if there was just one volcano on all of Earth,” Sori said. “That would be puzzling.”

Adding to the puzzle are the steep sides and well-defined features of Ahuna Mons – usually signs of geologic youth, Sori said. That leads to two possibilities: Ahuna Mons is just as it appears, inexplicably alone after forming relatively recently on an otherwise inactive world. Or, the cryovolcano is not alone or unusual, and there is some process on Ceres that has destroyed its predecessors and left the young Ahuna Mons as the solitary cryovolcano on the dwarf planet, according to Sori.

Ceres has no atmosphere, so the processes that wear down volcanoes on Earth – wind, rain and ice – aren’t possible on the dwarf planet. Sori and his colleagues hypothesized that another process, called viscous relaxation, could be at work.

Viscous relaxation is the idea that just about any solid will flow, given enough time. For example, a cold block of honey appears to be solid. But if given enough time, the block will flatten out until there is no sign left of the original block structure.

On Earth, viscous relaxation is what makes glaciers flow, Sori explained. The process doesn’t affect volcanoes on Earth because they are made of rock, but Ceres’s volcanoes contain ice – making viscous relaxation possible. On Ceres, viscous relaxation could be causing older cryovolcanoes to flatten out over millions of years so they are hard to discern. Ceres’s location close to the Sun could make the process more pronounced, Sori said.

To test the idea that viscous relaxation had caused cryovolcanoes to flatten out on Ceres, Sori and his colleagues created a model using the actual dimensions of Ahuna Mons to predict how fast the mountain might be flowing. They ran the model assuming different water contents of the material that makes up the mountain – ranging from 100 percent water ice to 40 percent water ice, Sori explained.

Ahuna Mons would need to be composed of more than 40 percent water ice to be affected by viscous relaxation, they found. At this composition, Sori estimates that Ahuna Mons should be flattening out at a rate of 10 to 50 meters (30 to 160 feet) per million years. That is enough to render cryovolcanoes unrecognizable in hundreds of millions to billions of years, suggesting there could have been other cryovolcanoes on Ceres, according to the new study.

“Ahuna Mons is at most 200 million years old. It just hasn’t had time to deform,” Sori said.

The next step for Sori and his team will be to try and identify the flattened remnants of older cryovolcanoes on Ceres. The findings could help scientists better decipher the history of how the dwarf planet formed, he added.

The new study helps scientists expand their knowledge of what might be possible on planetary bodies in our solar system, said Kelsi Singer, a postdoctoral researcher who studies icy worlds at Southwest Research Institute in Boulder, Colorado, and was not involved with the new research.

“It would be fun to check some of the other features that are potentially older domes on Ceres to see if they fit in with the theory of how the shapes should viscously evolve over time,” she said. “Because all of the putative cryovolcanic features on other worlds are different, I think this helps to expand our inventory of what is possible.”

TOP IMAGE….Ahuna Mons seen in a simulated perspective view. The elevation has been exaggerated by a factor of two. The view was made using enhanced-color images from NASA’s Dawn mission.
Credit: NASA


LOWER IMAGE….Ceres’ mysterious mountain Ahuna Mons is seen in this mosaic of images from NASA’s Dawn spacecraft. Dawn took these images from 385 kilometers (240 miles ) above the surface, in December 2015. The resolution of the image is 35 meters (120 feet) per pixel.
Credit: NASA

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The Dawn spacecraft has been exploring the two largest objects in the asteroid belt since 2007. Here’s what we’ve learned so far!

Ion Propulsion…What Is It?

Ion thrusters are being designed for a wide variety of missions – from keeping communications satellites in the proper position to propelling spacecraft throughout our solar system. But, what exactly is ion propulsion and how does an ion thruster work? Great question! Let’s take a look:

Regular rocket engines: You take a gas and you heat it up, or put it under pressure, and you push it out of the rocket nozzle, and the action of the gas going out of the nozzle causes a reaction that pushes the spacecraft in the other direction.

Ion engines: Instead of heating the gas up or putting it under pressure, we give the gas xenon a little electric charge, then they’re called ions, and we use a big voltage to accelerate the xenon ions through this metal grid and we shoot them out of the engine at up to 90,000 miles per hour.

Something interesting about ion engines is that it pushes on the spacecraft as hard as a single piece of paper pushes on your hand while holding it. In the zero gravity, frictionless, environment of space, gradually the effect of this thrust builds up. Our Dawn spacecraft uses ion engines, and is the first spacecraft to orbit two objects in the asteroid belt between Mars and Jupiter.

To give you a better idea, at full throttle, it would take our Dawn spacecraft four days to accelerate from zero to sixty miles per hour. That may sounds VERY slow, but instead of thrusting for four days, if we thrust for a week or a year as Dawn already has for almost five years, you can build up fantastically high velocity.

Why use ion engines? This type of propulsion give us the maneuverability to go into orbit and after we’ve been there for awhile, we can leave orbit and go on to another destination and do the same thing.

As the commercial applications for electric propulsion grow because of its ability to extend the operational life of satellites and to reduce launch and operation costs, we are involved in work on two different ion thrusters of the future: the NASA Evolutionary Xenon Thruster (NEXT) and the Annular Engine. These new engines will help reduce mission cost and trip time, while also traveling at higher power levels.

Learn more about ion propulsion HERE.

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SWRI SCIENTISTS DIG INTO THE ORIGIN OF ORGANICS ON CERES:
RESEARCH SUGGESTS ORGANIC MATERIALS ARE NATIVE TO THE DWARF PLANET

Since NASA’s Dawn spacecraft detected localized organic-rich material on Ceres, Southwest Research Institute (SwRI) has been digging into the data to explore different scenarios for its origin. After considering the viability of comet or asteroid delivery, the preponderance of evidence suggests the organics are most likely native to Ceres.

“The discovery of a locally high concentration of organics close to the Ernutet crater poses an interesting conundrum,” said Dr. Simone Marchi, a principal scientist at SwRI. He is discussing his team findings today at a press conference at the American Astronomical Society’s 49th Division for Planetary Sciences Meeting in Provo, Utah. “Was the organic material delivered to Ceres after its formation? Or was it synthesized and/or concentrated in a specific location on Ceres via internal processes? Both scenarios have shortfalls, so we may be missing a critical piece of the puzzle.”

Ceres is believed to have originated about 4.5 billion years ago at the dawn of our solar system. Studying its organics can help explain the origin, evolution, and distribution of organic species across the solar system. The very location of Ceres at the boundary between the inner and outer solar system and its intriguing composition characterized by clays, sodium- and ammonium-carbonates, suggest a very complex chemical evolution. The role of organics in this evolution is not fully understood, but has important astrobiological implications.

“Earlier research that focused on the geology of the organic-rich region on Ceres were inconclusive about their origin,” Marchi said. “Recently, we more fully investigated the viability of organics arriving via an asteroid or comet impact.”

Scientists explored a range of impact parameters, such as impactor sizes and velocities, using iSALE shock physics code simulations. These models indicated that comet-like projectiles with relatively high impact velocities would lose almost all of their organics due to shock compression. Impacting asteroids, with lower incident velocities, can retain between 20 and 30 percent of their pre-impact organic material during delivery, especially for small impactors at oblique impact angles. However, the localized spatial distribution of organics on Ceres seems difficult to reconcile with delivery from small main belt asteroids.

“These findings indicate that the organics are likely to be native to Ceres,” Marchi said.

IMAGE….SwRI scientists are studying the geology associated with the organic-rich areas on Ceres. Dawn spacecraft data show a region around the Ernutet crater where organic concentrations have been discovered (background image). The color coding shows the surface concentration of organics, as inferred from the visible and near infrared spectrometer. The inset shows a higher resolution enhanced color image of the Ernutet crater acquired by Dawn’s framing camera. Regions in red indicate higher concentration of organics.
Image courtesy of NASA/JPL-Caltech/UCLA/ASI/INAF/MPS/DLR/IDA

New technology that will change the world(s):

1. Ion Propulsion

(Image credit: NASA/JPL)

Technically not upcoming, ion propulsion is already a reality. Since it propels a spacecraft one particle at a time (as opposed to chemical propulsion, which explodes, generally, out the back), this propellant is hugely efficient.

The trick is what’s known to physicists as “specific impulse”. When a chemically propelled vehicle propels, it causes an explosion out the back, pushing the object forward. After exiting the vehicle however, the explosion immediately spreads in all directions, meaning that much of the energy of the explosion is lost on direction other than the one the spacecraft wishes to move.

Ion propulsion takes a long time to build speed but is so efficient that NASA’s Dawn spacecraft, being an ion propelled machine, is the first to be able to orbit multiple things in the solar system.

With ion propellant, a spacecraft may be able to even generate enough speed to allow for interstellar space exploration (meaning it could enable us to leave the Solar System). Though speculative, the possibility is undeniable.

2. Solar Sailing

(Image credit: NASA)

This technology is still controversial. The science is this:

Light has momentum. When light hits a highly reflective surface, the surface, is pushed. With gradual building of velocity, a spacecraft could easily attain vast speeds, again leading to aspirations toward interstellar exploration.

The advantage over ion propulsion though, is that this is exploration without propellant.

Such methods of discovery haven’t been relevant since our ancestors explored the Earth on boats driven by the wind.

Though the science is known, the engineering applications are still somewhat mysterious.

The momentum gained from a single photon is very small. The area of material needed for a solar sail that could carry something like a generation starship is many orders of magnitude larger than any tested solar sail concept. It’s arguable whether or not this technology would ultimately turn out to be the most efficient way to go.

That space exploration is expensive means that when someone bothers to pay for a launch, the first thing they would hate to do is lose their spacecraft because it turns out to not be able to propel itself. Most bankrollers of space travel tend to favor tried and true methods.

That said, the testing of solar sails is underway.

Agencies like NASA, JAXA and even the Planetary Society (holla) are currently undergoing mission preparation, or already have a mission underway, testing solar sails.

3. Renewable Rocketry

(Image credit: SpaceX)

This one’s a biggie.

Imagine, you buy a car. You go buy groceries, come home and then your car explodes.

Every. Single. Time.

Tell me, could you afford to buy a new car every week to buy groceries, or would you figure something else out?

Personally, I wouldn’t be able to travel by car. I just don’t have the money to buy a new one every week.

Space exploration faces the same problem. Rocket technology was mostly driven and invented by military ventures that didn’t care about getting the rocket back. In fact, for a military rocket - if you see it coming back at you then you’ve probably done something wrong.

New efforts are underway to change this.

Companies like SpaceX, Reaction Engines and Blue Origin are devising groundbreaking new technologies that are fundamentally different from the rocketry of yesteryear.

Soon SpaceX will be carrying people into low Earth orbit, dropping them off and returning to a landing pad in Florida.

Reaction Engines Ltd has invented a hybrid rocket engine which breathes oxygen from the atmosphere like a jet engine, then becomes a spacecraft engine once the air becomes too thin (meaning it needs a fraction of the fuel to get to space as most others).

Blue Origin plans on carrying tourists to the edge of space, with the rocket then returning to the landing pad softly on a plume of fire.

Each of these ventures has already proven their technology. They’re each on the road to implementing it now, with both SpaceX and Blue Origin currently launching with the technology.

Let me give you an idea of how much this is going to change humanity:

The cost of a SpaceX Falcon 9 launch is around $61 million.

Of that, the cost of fuel is about $200,000 (according to SpaceX).

In two years, SpaceX will be regularly launching seven astronauts at a time to the space station.

If all you need to pay for (approximately) is the cost of fuel (similar to fueling up your car), the cost of fuel between seven to get to space drops to a potential $28,500 or so.

Though still expensive, it’s easily within the bounds of startup companies to launch to space on commercial endeavors, meaning there will be private sector astronaut positions opening up in the very near future (they already exist actually).

Some vacations cost more than this. It’s within the bounds of reason to expect such entertainment prospects to carry into orbit.

Imagine: zero-gravity theme parks and floating hotels where you can watch, romantically as the Sun sets on the Earth below 16 times a day and you can see the Northern lights, lightning storms and the artificial spark of city lights spread out below you like some wondrous surreal painting.

With companies already developing espresso machines and cups for microgravity, and astronauts already testing greenhouses that grow vegetables in orbit, it seems inevitable that humanity is on the cusp of realizing the experience of the final frontier.


(More technologies to come in a later post)

What Are the Bright Spots on Ceres?

Dwarf planet Ceres has more than 130 bright areas, and most of them are associated with impact craters. Now, Ceres has revealed some of its well-kept secrets in two new studies in the journal Nature, thanks to data from our Dawn spacecraft.

Two studies have been looking into the mystery behind these bright areas. One study identifies this bright material as a kind of salt, while the other study suggests the detection of ammonia-rich clays. 

Study authors write that the bright material is consistent with a type of magnesium sulfate called hexahydrite. A different type of magnesium sulfate is familiar on Earth as Epsom salt.

Researchers, using images from Dawn’s framing camera, suggest that these salt-rich areas were left behind when water-ice sublimated in the past. Impacts from asteroids would have unearthed the mixture of ice and salt.

An image of Occator Crater (below) shows the brightest material on Ceres. Occator itself is 60 miles in diameter, and its central pit, covered by this bright material, measures about 6 miles wide. With its sharp rim and walls, it appears to be among the youngest features on the dwarf planet.

In the second nature study, members of the Dawn science team examined the composition of Ceres and found evidence for ammonia-rich clays. Why is this important?

Well, ammonia ice by itself would evaporate on Ceres today, because it is too warm. However, ammonia molecules could be stable if present in combination with other minerals. This raises the possibility that Ceres did not originate in the main asteroid belt between Mars and Jupiter, where it currently resides. But instead, might have formed in the outer solar system! Another idea is that Ceres formed close to its present position, incorporating materials that drifted in from the outer solar system, near the orbit of Neptune, where nitrogen ices are thermally stable.

As of this week, our Dawn spacecraft has reached its final orbital altitude at Ceres (about 240 miles from the surface). In mid-December, it will begin taking observations from this orbit, so be sure to check back for details!

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The dwarf planet Ceres, imaged by the Dawn spacecraft, May 3rd - 4th 2015.  This world is the largest object in the asteroid belt, with a diameter of 950 kilometers. Ceres is likely a protoplanet, left over from the formation of our solar system 4.6 billion years ago.  Its interior is probably a mixture of rock and water ice, while mysterious bright features on the surface hint at geological activity.  (Note: this animation has been rotated 180 ° so that the North pole faces downwards)

How Well Do You Know Your Space Photos?

Can you guess the subject of each of these pictures? How many will you get right? Test your friends and family to see who knows their space photos the best.

1. Ice on Earth or a Picture of Mars?

2. Dry Land on Earth or a Close-Up of Jupiter?

3. Mercury or Our Moon?

4. Do You Think This is Mars or Our Home Planet?

5. Waves on Jupiter or Saturn?

6. Is this a picture of Mars or Earth?

7. Can You Tell Which is Europa and Which is the Bottom of a Frying Pan?

8. Close-Up of Our Moon or Dwarf Planet Ceres?

9. A Weird World or Our Own World?

10. The Red Planet or a Red Desert?


Answers

1. Mars. You might be surprised, but this image taken by our Mars Reconnaissance Orbiter is of a light-toned deposit on the Martian surface. Some shapes in the terrain suggest erosion by a fluid moving north to south.

2. Earth. This image taken by our Earth Observing-1 satellite shows Lake Frome in central Australia. In this image, the salt lake appears bone-dry, filled with off-white sediment. This area of Australia receives 149 to 216 millimeters of rainfall a year on average, and the basins pass most of their time as saltpans.

3. Mercury. Our MESSENGER spacecraft captured this image of Mercury during a fly by in October 2008. It shows previously uncharted regions of the planet that have large craters with an internal smoothness similar to Earth’s own moon. It is thought that these craters were to have been flooded by lava flows that are old but not as old as the surrounding more highly cratered surface.

4. Earth. Surprisingly, this image take from the International Space Station shows the western half of the Arabian peninsula in Saudi Arabia. It not only contains large expanses of sand and gravel, but extensive lava fields known as haraat.

5. Saturn. Although this pattern of waves is similar to those seen on Jupiter, this is actually a picture of Saturn. The pattern of an iconic surfer’s wave, has been observed in many places all over the universe, including at the edges of Earth’s magnetic environment.

6. Mars. This image was taken by our Mars Reconnaissance Orbiter and shows dunes of sand-sized materials that have been trapped on the floors of many Martian craters. The dunes are linear, thought to be due to shifting wind directions.

7. Left: Europa. Right: Frying Pan. Europa is one of Jupiter’s moons, and is about the same size as Earth’s moon.

8. Ceres. This image taken by our Dawn spacecraft shows an intriguing mountain on dwarf planet Ceres protruding from a relatively smooth area.

9. Earth. This image of the Bazman volcano is located in a remote region of souther Iran. While the volcano has the classic cone shape of a stratovolcano, it is also heavily dissected by channels that extend downwards from the summit.

10. Earth. This image of the Great Sandy Desert in northwest Australia shows a variety of dune forms across the region. The photo was taken by the Expedition 35 crew from the International Space Station.

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Secret of Ceres’ weird bright spots finally revealed?

Bad news for those of you hoping Ceres and its odd bright spots might be an alien base or real-life Death Star. The largest object in the asteroid belt between Mars and Jupiter isn’t beaming ominous rays of light at NASA’s Dawn spacecraft via huge artificial headlights, it turns out.

Since Dawn first spotted a number of bright spots earlier this year as it approached the dwarf planet – including some particularly large bright areas in the center of a crater 60 miles (90 kilometers) wide near the middle of Ceres – we’ve heard all kinds of explanations, both boring (ice or salt) and far-fetched (a hidden alien base!).

Two new studies published in the latest issue of the journal Nature seem to confirm scientists’ earlier educated guess that the bright reflective material is a kind of salt, and one of the studies also suggests the presence of ammonia-rich clays, providing additional insights into Ceres’ history.

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New Ceres Views as Dawn Moves Higher


The brightest area on Ceres stands out amid shadowy, cratered terrain in a dramatic new view from NASA’s Dawn spacecraft, taken as it looked off to the side of the dwarf planet. Dawn snapped this image on Oct. 16, from its fifth science orbit, in which the angle of the sun was different from that in previous orbits. Dawn was about 920 miles (1,480 kilometers) above Ceres when this image was taken – an altitude the spacecraft had reached in early October.

Occator Crater, with its central bright region and secondary, less-reflective areas, appears quite prominent near the limb, or edge, of Ceres. At 57 miles (92 kilometers) wide and 2.5 miles (4 kilometers) deep, Occator displays evidence of recent geologic activity. The latest research suggests that the bright material in this crater is comprised of salts left behind after a briny liquid emerged from below, froze and then sublimated, meaning it turned from ice into vapor.

The impact that formed the crater millions of years ago unearthed material that blanketed the area outside the crater, and may have triggered the upwelling of salty liquid.

“This image captures the wonder of soaring above this fascinating, unique world that Dawn is the first to explore,” said Marc Rayman, Dawn’s chief engineer and mission director, based at NASA’s Jet Propulsion Laboratory, Pasadena, California.

Dawn scientists also have released an image of Ceres that approximates how the dwarf planet’s colors would appear to the human eye. This view, produced by the German Aerospace Center in Berlin, combines images taken from Dawn’s first science orbit in 2015, using the framing camera’s red, green and blue filters. The color was calculated based on the way Ceres reflects different wavelengths of light.

The spacecraft has gathered tens of thousands of images and other information from Ceres since arriving in orbit on March 6, 2015. After spending more than eight months studying Ceres at an altitude of about 240 miles (385 kilometers), closer than the International Space Station is to Earth, Dawn headed for a higher vantage point in August. In October, while the spacecraft was at its 920-mile altitude, it returned images and other valuable insights about Ceres.

On Nov. 4, Dawn began making its way to a sixth science orbit, which will be over 4,500 miles (7,200 kilometers) from Ceres. While Dawn needed to make several changes in its direction while spiraling between most previous orbits at Ceres, engineers have figured out a way for the spacecraft to arrive at this next orbit while the ion engine thrusts in the same direction that Dawn is already going. This uses less hydrazine and xenon fuel than Dawn’s normal spiral maneuvers. Dawn should reach this next orbit in early December.

One goal of Dawn’s sixth science orbit is to refine previously collected measurements. The spacecraft’s gamma ray and neutron spectrometer, which has been investigating the composition of Ceres’ surface, will characterize the radiation from cosmic rays unrelated to Ceres. This will allow scientists to subtract “noise” from measurements of Ceres, making the information more precise.

The spacecraft is healthy as it continues to operate in its extended mission phase, which began in July. During the primary mission, Dawn orbited and accomplished all of its original objectives at Ceres and protoplanet Vesta, which the spacecraft visited from July 2011 to September 2012.

Dawn’s mission is managed by NASA’s Jet Propulsion Laboratory for NASA’s Science Mission Directorate in Washington. Dawn is a project of the directorate’s Discovery Program, managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team.

TOP IMAGE….Occator on Ceres’ Limb This image of the limb of dwarf planet Ceres shows a section of the northern hemisphere. Prominently featured is Occator Crater, home of Ceres’ intriguing brightest areas.
At 57 miles (92 kilometers) wide and 2.5 miles (4 kilometers) deep, Occator displays evidence of recent geologic activity. The latest research suggests that the bright material in this crater is comprised of salts left behind after a briny liquid emerged from below, froze and then sublimated, meaning it turned from ice into vapor. Dawn took this image on Oct. 17 from its second extended-mission science orbit (XMO2), at a distance of about 920 miles (1,480 kilometers) above the surface. The image resolution is about 460 feet (140 meters) per pixel.


LOWER IMAGE….Ceres in Color This image of Ceres approximates how the dwarf planet’s colors would appear to the eye. This view of Ceres, produced by the German Aerospace Center in Berlin, combines images taken during Dawn’s first science orbit in 2015 using the framing camera’s red, green and blue spectral filters. The color was calculated using a reflectance spectrum, which is based on the way that Ceres reflects different wavelengths of light and the solar wavelengths that illuminate Ceres.

Solar System: 2015 Year in Review

Two mysterious worlds explored for the first time. Liquid water seen flowing on Mars. A global ocean discovered hiding inside a moon of Saturn. Even during our Era of audacious solar system exploration, 2015 stands out. Here are a few highlights:

1. New Horizons Reveals the Face of Pluto

Whether or not you call it a planet, Pluto entranced the people of Earth when it sent a love note from three billion miles away via our New Horizons spacecraft.

2. Dawn Comes to Ceres

The dwarf planet Ceres, the largest object in the main asteroid belt, teased explorers with its bizarre bright spots before finally giving up some of its secrets to the Dawn spacecraft. HERE are the latest findings.

3. Cassini Marks Discoveries and Milestones at Enceladus

When the Cassini spacecraft performs its final close flyby of Saturn’s icy moon Enceladus on Dec. 19, it will be a true milestone. Scientists using data from Cassini’s instruments have uncovered astounding secrets about this small moon, including (confirmed this year) the fact that its underground ocean of liquid water is global, and is home to hydrothermal vents.

4. We Confirmed Evidence that Liquid Water Flows on Today’s Mars

Findings from our Mars Reconnaissance Orbiter (MRO) provided the strongest evidence yet that liquid water flows intermittently — on present-day Mars.

5. Rosetta Passes Perihelion

The European Space Agency’s Rosetta mission had a remarkable year, re-establishing contact with the Philae lander and following comet 67P/Churyumov-Gerasimenko as it swung near the sun.

6. Mars Explorers Confirm Lakes Once Dotted Mars

A study from the team behind our Mars Science Laboratory/Curiosity Rover confirmed that Mars was once, billions of years ago, capable of storing water in lakes over an extended period of time.

7. MAVEN Finds a Culprit in the Loss of Mars’ Atmosphere

The Mars Atmosphere and Volatile Evolution (MAVEN) mission identified the process that appears to have played a key role in the transition of the Martian climate from an early, warm and wet environment that might have supported surface life to the cold, arid planet that Mars is today.

8. Akatsuki Gets a Second Chance at Venus

Five years after a mishap sent the spacecraft off course, the Japan Aerospace Exploration Agency (JAXA) successfully inserted the Venus Climate Orbiter “Akatsuki” into orbit around Venus. While the mission is not funded by NASA, an agency partnership with JAXA provides an opportunity for eight of our scientists to work with the Akatsuki team and study data from the spacecraft over the next year or so.

9. A Trailblazing Mission Sends Its Final Message from Mercury

After a flight of nearly 11 years, the highly successful MESSENGER mission ended when, as planned, the spacecraft slammed into the surface of Mercury.

10. Mars Reconnaissance Orbiter Completes 40,000 Orbits

Mars Reconnaissance Orbiter, at Mars since 2006, has orbited the Red Planet more than 40,000 times. The mission, which studies the whole planet from space, has shown that Mars is diverse and dynamic by way of many thousands of spectacular images and other kinds of data.

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Ceres, the closest dwarf planet, has its mysteries solved by NASA

3.) The second brightest crater on Ceres, Oxo, is the only location that exhibits surface water. This small, 9 kilometer (6 mile) wide crater is most likely very young, as water ice should sublimate in the sunlight on timescales of a few million years at most: much shorter than the lifetime of this world. Either it’s one of the most recent impact craters, and practically all impact craters dredge up subsurface water, or there’s been recent landslide that exposed this water. Future analyses should be able to reveals whether there’s other water-ice on the surface (at lower density than what’s found here), as well as determining whether this is pure water-ice, or whether this is frozen water that’s bound into minerals, making them more stable against sublimation than water-ice on its own.”

NASA’s Dawn mission has just revealed a huge suite of data about Ceres, our Solar System’s closest dwarf planet. No longer merely taking pictures, at its orbital altitude of just 240 miles (385 km), it’s now gathering information from many instruments, measuring the chemical composition and neutron/gamma ray fluxes from the surface. Three big surprises have emerged, including a new theory for the salt deposits in Occator crater, the possible existence of sub-surface icecaps at the poles, and a new set of white spots in Oxo crater, which are water-ice after all!