NASA's Dawn mission to the asteroids

[Rick]

New Names and Insights at Ceres

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.

More: http://www.jpl.nasa.gov/news/news.php?feature=4669

[Rick]

Flying on a blue-green ray of xenon ions, Dawn is gracefully descending toward dwarf planet Ceres. Even as Dawn prepares for a sumptuous new feast in its next mapping orbit, scientists are continuing to delight in the delicacies Ceres has already served. With a wonderfully rich bounty of pictures and other observations already secured, the explorer is now on its way to an even better vantage point.

More: http://dawnblog.jpl.nasa.gov/2015/07/29/dawn-journal-july-29/

[Rick]

Cruise Over Ceres in New Video

Striking 3-D detail highlights a towering mountain, the brightest spots and other features on dwarf planet Ceres in a new video from NASA's Dawn mission.

A prominent mountain with bright streaks on its steep slopes is especially fascinating to scientists. The peak's shape has been likened to a cone or a pyramid. It appears to be about 4 miles (6 kilometers) high, with respect to the surface around it, according to the latest estimates. This means the mountain has about the same elevation as Mount McKinley in Denali National Park, Alaska, the highest point in North America.

More: http://www.jpl.nasa.gov/news/news.php?feature=4677

[Rick]

Dawn Sends Sharper Scenes from Ceres

The closest-yet views of Ceres, delivered by NASA's Dawn spacecraft, show the small world's features in unprecedented detail, including Ceres' tall, conical mountain; crater formation features and narrow, braided fractures.

"Dawn is performing flawlessly in this new orbit as it conducts its ambitious exploration. The spacecraft's view is now three times as sharp as in its previous mapping orbit, revealing exciting new details of this intriguing dwarf planet," said Marc Rayman, Dawn's chief engineer and mission director, based at NASA's Jet Propulsion Laboratory, Pasadena, California.

More: http://www.jpl.nasa.gov/news/news.php?feature=4697

[Rick]

Ceres' Bright Spots Seen in Striking New Detail

The brightest spots on the dwarf planet Ceres gleam with mystery in new views delivered by NASA's Dawn spacecraft. These closest-yet views of Occator crater, with a resolution of 450 feet (140 meters) per pixel, give scientists a deeper perspective on these very unusual features.

The new up-close view of Occator crater from Dawn's current vantage point reveals better-defined shapes of the brightest, central spot and features on the crater floor. Because these spots are so much brighter than the rest of Ceres' surface, the Dawn team combined two different images into a single composite view -- one properly exposed for the bright spots, and one for the surrounding surface.

Scientists also have produced animations that provide a virtual fly-around of the crater, including a colorful topographic map.

More: http://www.jpl.nasa.gov/news/news.php?feature=4714

[Rick]

Dawn Heads Toward Final Orbit

NASA's Dawn spacecraft fired up its ion engine on Friday, Oct. 23, to begin its journey toward its fourth and final science orbit at dwarf planet Ceres. The spacecraft completed two months of observations from an altitude of 915 miles (1,470 kilometers) and transmitted extensive imagery and other data to Earth.

The spacecraft is now on its way to the final orbit of the mission, called the low-altitude mapping orbit. Dawn will spend more than seven weeks descending to this vantage point, which will be less than 235 miles (380 kilometers) from the surface of Ceres. In mid-December, Dawn will begin taking observations from this orbit, including images at a resolution of 120 feet (35 meters) per pixel.

More: http://www.jpl.nasa.gov/news/news.php?feature=4751

[Rick]

Dawn Journal - October 30, 2015

Dawn has completed another outstandingly successful campaign to acquire a wealth of pictures and other data in its exploration of dwarf planet Ceres. Exultant residents of distant Earth now have the clearest and most complete view ever of this former planet.

More: http://dawnblog.jpl.nasa.gov/2015/10/30/dawn-journal-october-30/

[Rick]

What smacks into Ceres stays on Ceres

Ceres is the largest object in the asteroid belt and the nearest dwarf planet to Earth. Until the recent arrival of the Dawn spacecraft, all that was known about Ceres came from telescopic observations. The observations showed Ceres to be mysteriously low in density, suggesting it is made either of very porous silicate material, or perhaps contains a large layer of water ice. Observations of its surface were remarkable as well — largely for being unremarkable.

"It's really bland in the telescopic observations," said Daly, a Ph.D. student at Brown and the study's lead author. "It's like someone took a single color of spray paint and sprayed the whole thing. When we think about what might have caused this homogeneous surface, our thoughts turn to impact processes."

And to understand impact processes, the researchers turned to NASA's Vertical Gun Range, a cannon with a 14-foot barrel that can launch projectiles at up to 16,000 miles per hour. For this work, Daly and Schultz wanted to simulate impacts into low-density surfaces that mimic the two broad possibilities for the composition of Ceres's surface: porous silicate or icy.

More: https://news.brown.edu/articles/2015/10/ceres

[Rick]

Dawn Journal - November 30, 2015

An intrepid interplanetary explorer is now powering its way down through the gravity field of a distant alien world. Soaring on a blue-green beam of high-velocity xenon ions, Dawn is making excellent progress as it spirals closer and closer to Ceres, the first dwarf planet discovered. Meanwhile, scientists are progressing in analyzing the tremendous volume of pictures and other data the probe has already sent to Earth.

More: http://dawnblog.jpl.nasa.gov/2015/11/30/dawn-journal-november-30/

[Rick]

New Clues to Ceres' Bright Spots and Origins

Ceres has more than 130 bright areas, and most of them are associated with impact craters. Study authors, led by Andreas Nathues at Max Planck Institute for Solar System Research, Göttingen, Germany, 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.

Nathues and colleagues, 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, they say.

"The global nature of Ceres' bright spots suggests that this world has a subsurface layer that contains briny water-ice," Nathues said.

More: http://www.jpl.nasa.gov/news/news.php?feature=4785

[Rick]

Ceres: Keeping Well-Guarded Secrets for 215 Years

New Year's Day, 1801, the dawn of the 19th century, was a historic moment for astronomy, and for a space mission called Dawn more than 200 years later. That night, Giuseppe Piazzi pointed his telescope at the sky and observed a distant object that we now know as Ceres.

Today, NASA's Dawn mission allows us to see Ceres in exquisite detail. From the images Dawn has taken over the past year, we know Ceres is a heavily cratered body with diverse features on its surface that include a tall, cone-shaped mountain and more than 130 reflective patches of material that is likely salt. But on that fateful evening in 1801, Piazzi wasn't sure what he was seeing when he noticed a small, faint light through his telescope.

"When Piazzi discovered Ceres, exploring it was beyond imagination. More than two centuries later, NASA dispatched a machine on a cosmic journey of more than 3 billion miles to reach the distant, mysterious world he glimpsed," said Marc Rayman, mission director and chief engineer for Dawn at NASA's Jet Propulsion Laboratory, Pasadena, California.

More: http://www.jpl.nasa.gov/news/news.php?feature=4824

[Rick]

New Animation Takes a Colorful Flight Over Ceres

A colorful new animation shows a simulated flight over the surface of dwarf planet Ceres, based on images from NASA's Dawn spacecraft.

The movie shows Ceres in enhanced color, which helps to highlight subtle differences in the appearance of surface materials. Scientists believe areas with shades of blue contain younger, fresher material, including flows, pits and cracks.

The animated flight over Ceres emphasizes the most prominent craters, such as Occator, and the tall, conical mountain Ahuna Mons. Features on Ceres are named for earthly agricultural spirits, deities and festivals.

More: http://www.jpl.nasa.gov/news/news.php?feature=4836

[Rick]

Dawn's First Year at Ceres: A Mountain Emerges

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.

More: http://www.jpl.nasa.gov/news/news.php?feature=5745

[Rick]

Bright Spots and Color Differences Revealed on Ceres

Occator Crater, measuring 57 miles (92 kilometers) across and 2.5 miles (4 kilometers) deep, contains the brightest area on Ceres, the dwarf planet that Dawn has explored since early 2015. The latest images, taken from 240 miles (385 kilometers) above the surface of Ceres, reveal a dome in a smooth-walled pit in the bright center of the crater. Numerous linear features and fractures crisscross the top and flanks of this dome. Prominent fractures also surround the dome and run through smaller, bright regions found within the crater.

MNore: http://www.jpl.nasa.gov/news/news.php?feature=6168

[Rick]

Occator Crater and Ceres' Brightest Spots

One year after taking up its new residence in the solar system, Dawn is continuing to witness extraordinary sights on dwarf planet Ceres. The indefatigable explorer is carrying out its intensive campaign of exploration from a tight orbit, circling its gravitational master at an altitude of only 240 miles (385 kilometers).

Even as we marvel at intriguing pictures and other discoveries, scientists are still in the early stages of putting together the pieces of the big puzzle of how (and where) Ceres formed, what its subsequent history has been, what geological processes are still occurring on this alien world and what all that reveals about the solar system.

More: http://dawnblog.jpl.nasa.gov/2016/03/31/dawn-journal-march-31-3/