Mar 15

Puzzling Bright Spots on Dwarf Planet Ceres

Source: NASA Science News

Ceres-bright-spotTwo views of Ceres acquired by Dawn  on Feb. 12, 2015, from a distance of about 83,000 kilometers as the dwarf planet rotated.
Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Researchers are puzzled by a number of bright spots on Ceres, which are coming into focus as NASA's Dawn spacecraft approaches the dwarf planet. (read more)

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Mar 15

Dawn’s Arrival at Ceres

Source: Dawn Mission Education and Communications

Note the timeline at upper right.

Dawn will enter Ceres' orbit on the first days of May 2015. This animation gives a three-dimensional view of Dawn’s complex approach to Ceres. The spacecraft deftly maneuvers into orbit with its ion propulsion system, flying to RC3 orbit, which is achieved when the thrust is turned off. (The size of Ceres is exaggerated compared to the size of the orbit here.) At the end, the viewpoint shifts to provide another perspective on the unique trajectory.

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Dec 13

Dwarf Planet Ceres - 'A Game Changer in the Solar System'

Credits: Space Daily


In March of 2015, NASA's Dawn mission will arrive at the dwarf planet Ceres, the first of the smaller class of planets to be discovered and the closest to Earth. Ceres, which orbits the Sun in the asteroid belt between Mars and Jupiter, is a unique body in the Solar System, bearing many similarities to Jupiter's moon Europa and Saturn's moon Enceladus, both considered to bepotential sources for harboring life. (read more)

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Mar 12

Dawn Sees New Surface Features on Giant Asteroid Vesta

Source: NASA News

Bright material extends out from the crater Canuleia on Vesta.
Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/UMD.

NASA's Dawn spacecraft has revealed unexpected details on the surface of the giant asteroid Vesta. New images and data highlight the diversity of Vesta's surface and reveal unusual geologic features, some of which were never previously seen on asteroids.

Vesta is one of the brightest objects in the solar system and the only asteroid in the so-called main belt between Mars and Jupiter visible to the naked eye from Earth. Dawn found that some areas on Vesta can be nearly twice as bright as others, revealing clues about the asteroid's history.

"Our analysis finds this bright material originates from Vesta and has undergone little change since the formation of Vesta over 4 billion years ago," said Jian-Yang Li, a Dawn participating scientist at the University of Maryland, College Park. "We're eager to learn more about what minerals make up this material and how the present Vesta surface came to be."

Bright areas appear everywhere on Vesta but are most predominant in and around craters. The areas vary from several hundred feet to around 10 miles across. Rocks crashing into the surface of Vesta seem to have exposed and spread this bright material. This impact process may have mixed the bright material with darker surface material.

While scientists had seen some brightness variations in previous images of Vesta from NASA's Hubble Space Telescope, Dawn scientists also did not expect such a wide variety of distinct dark deposits across its surface. The dark materials on Vesta can appear dark gray, brown and red. They sometimes appear as small, well-defined deposits around impact craters. They also can appear as larger regional deposits, like those surrounding the impact craters scientists have nicknamed the "snowman."

"One of the surprises was the dark material is not randomly distributed," said David Williams, a Dawn participating scientist at Arizona State University, Tempe. "This suggests underlying geology determines where it occurs."

The dark materials seem to be related to impacts and their aftermath. Scientists theorize carbon-rich asteroids could have hit Vesta at speeds low enough to produce some of the smaller deposits without blasting away the surface.

Higher-speed asteroids also could have hit the asteroid's surface and melted the volcanic basaltic crust, darkening existing surface material. That melted conglomeration appears in the walls and floors of impact craters, on hills and ridges, and underneath brighter, more recent material called ejecta, which is material thrown out from a space rock impact.

Vesta's dark materials suggest the giant asteroid may preserve ancient materials from the asteroid belt and beyond, possibly from the birth of the solar system.

"Some of these past collisions were so intense they melted the surface," said Brett Denevi, a Dawn participating scientist at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md. "Dawn's ability to image the melt marks a unique find. Melting events like these were suspected, but never before seen on an asteroid."

Dawn launched in September 2007. It will reach its second destination, Ceres, in February 2015.

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Dec 11

Is Vesta the "Smallest Terrestrial Planet?"

Source: NASA News

NASA's Dawn probe, now orbiting Vesta in the asteroid belt, has found some surprising things on the giant asteroid--things that have prompted one researcher to declare Vesta "the smallest terrestrial planet."(read more)

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Sep 11

NASA releases video about DAWN adn Vesta

Source: NASA/JPL

Go to video webpage.

NASA and JPL have just released a video about the close encounconter of space probe DAWN with asteroid Vesta. On the video one can notice that Vesta is not entirely lit up. There is no light in the high northern latitudes because, like Earth, Vesta has seasons. Currently it is northern winter on Vesta, and the northern polar region is in perpetual darkness. When we view Vesta's rotation from above the south pole, half is in darkness simply because half of Vesta is in daylight and half is in the darkness of night . (see video webpage).

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Aug 11

Dawn's smooth orbital insertion at Vesta

Source: NASA Science News

Dawn's image of Vesta on July 24, 2011.
Image credits: NASA/Dawn.

When a NASA spacecraft goes into orbit around a new world for the first time, the control room is usually packed to capacity with scientists, engineers, and dignitaries ready to leap and shout when the retro-rockets fire. It's a big, noisy event.

July 15, 2011, was one of those days. NASA's Dawn spacecraft approached Vesta and became the first probe from Earth to orbit a main belt asteroid. Dawn's cameras revealed a desolate world of transcendent beauty, thrilling everyone who worked on the project.

Needless to say, the control room was .... silent?

This was because with Dawn all could be fuel controlled previously. (read more)

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Jul 11

Dawn spacecraft returns close-up Image of asteroid Vesta

Source: NASA/Dawn

Dawn spacecraft obtained this image on July 17, 2011.
Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

NASA's Dawn spacecraft has returned the first close-up image after beginning its orbit around the giant asteroid Vesta. On Friday, July 15, Dawn became the first probe to enter orbit around an object in the main asteroid belt between Mars and Jupiter.

The image taken for navigation purposes shows Vesta in greater detail than ever before. When Vesta captured Dawn into its orbit, there were approximately 16 000 kilometers between the spacecraft and asteroid.

Vesta is 330 miles (530 kilometers) in diameter and the second most massive object in the asteroid belt. Ground- and space-based telescopes have obtained images of Vesta for about two centuries, but they have not been able to see much detail on its surface.(read more)

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Jul 11

DAWN spacecraft enters orbit around asteroid Vesta


Artist's impression of Dawn.
Image credit: NASA/JPL.

NASA's Dawn spacecraft on Saturday became the first probe ever to enter orbit around an object in the main asteroid belt between Mars and Jupiter.

Dawn will study the asteroid, named Vesta, for a year before departing for a second destination, a dwarf planet named Ceres, in July 2012. Observations will provide unprecedented data to help scientists understand the earliest chapter of our solar system. The data also will help pave the way for future human space missions.(read more)

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Jul 11

Dawn Set to Orbit Giant Asteroid Vesta on July 15th

Source: NASA

Dawn's image of giant asteroid Vesta on July 9, 2011.
Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.


On July 15, NASA's ion-propelled Dawn spacecraft will become the first mission to enter orbit around a main-belt asteroid. Dawn will orbit Vesta for one Earth-year, studying the giant space rock at close range to help scientists understand the earliest chapter of our solar system's history.(read more)

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Jul 11

Does Asteroid Vesta Have a Moon?

Source: NASA

Ida and Dactyl: Asteroid and Moon
Credit: Galileo Project, JPL, NASA

As NASA's ion-powered Dawn spacecraft approaches Vesta for orbital insertion in mid-July, Dawn's camera's will be scanning space around the giant asteroid for signs of an asteroid moon.(read more)

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Jun 11

NASA spacecraft captures video of asteroid approach

Source: NASA/Dawn

Artist's impression of Dawn. Image credit: NASA.

Scientists working with NASA's Dawn spacecraft have created a new video showing the giant asteroid Vesta as the spacecraft approaches this unexplored world in the main asteroid belt.

The video loops 20 images obtained for navigation purposes on June 1. The images show a dark feature near Vesta's equator moving from left to right across the field of view as Vesta rotates. Images also show Vesta's jagged, irregular shape, hinting at the enormous crater known to exist at Vesta's south pole. (read more)

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