Category Archives: Dawn

Dawn Mission Extended


The Dawn mission extended for about another year. Here’s the details:

NASA — NASA has authorized a second extension of the Dawn mission at Ceres, the largest object in the asteroid belt between Mars and Jupiter. During this extension, the spacecraft will descend to lower altitudes than ever before at the dwarf planet, which it has been orbiting since March 2015. The spacecraft will continue at Ceres for the remainder of its science investigation and will remain in a stable orbit indefinitely after its hydrazine fuel runs out.

The Dawn flight team is studying ways to maneuver Dawn into a new elliptical orbit, which may take the spacecraft to less than 120 miles (200 kilometers) from the surface of Ceres at closest approach. Previously, Dawn’s lowest altitude was 240 miles (385 kilometers).

A priority of the second Ceres mission extension is collecting data with Dawn’s gamma ray and neutron spectrometer, which measures the number and energy of gamma rays and neutrons. This information is important for understanding the composition of Ceres’ uppermost layer and how much ice it contains.

The spacecraft also will take visible-light images of Ceres’ surface geology with its camera, as well as measurements of Ceres’ mineralogy with its visible and infrared mapping spectrometer.

The extended mission at Ceres additionally allows Dawn to be in orbit while the dwarf planet goes through perihelion, its closest approach to the Sun, which will occur in April 2018. At closer proximity to the Sun, more ice on Ceres’ surface may turn to water vapor, which may in turn contribute to the weak transient atmosphere detected by the European Space Agency’s Herschel Space Observatory before Dawn’s arrival. Building on Dawn’s findings, the team has hypothesized that water vapor may be produced in part from energetic particles from the Sun interacting with ice in Ceres’ shallow surface. Scientists will combine data from ground-based observatories with Dawn’s observations to further study these phenomena as Ceres approaches perihelion.

The Dawn team is currently refining its plans for this next and final chapter of the mission. Because of its commitment to protect Ceres from Earthly contamination, Dawn will not land or crash into Ceres. Instead, it will carry out as much science as it can in its final planned orbit, where it will stay even after it can no longer communicate with Earth. Mission planners estimate the spacecraft can continue operating until the second half of 2018.

Dawn is the only mission ever to orbit two extraterrestrial targets. It orbited giant asteroid Vesta for 14 months from 2011 to 2012, then continued on to Ceres, where it has been in orbit since March 2015.

The Dawn mission is managed by JPL 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.

Thanks and Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Juling Crater on Ceres

The Dawn mission is still going strong.  In fact Dawn just came to within 5,200 km / 3,230 mi of the surface of the dwarf planet Ceres (22 Aug 17).  The image below is from about two years ago on 25 Aug 2016 when Dawn was much closer, at an altitude of only 385 km / 240 mi.

This high-resolution image of Juling Crater on Ceres reveals, in exquisite detail, features on the rims and crater floor. The crater is about 1.6 miles (2.5 kilometers) deep and the small mountain, seen left of the center of the crater, is about 0.6 miles (1 kilometers) high. The many features indicative of the flow of material suggest the subsurface is rich in ice. The geological structure of this region, as seen in PIA21753, also generally suggests that ice is involved.

The origin of the small depression seen at the top of the mountain is not fully understood but might have formed as a consequence of a landslide, visible on the northeastern flank.

Juling is named after the Sakai/Orang Asli spirit of the crops from Malaysia.

NASA’s Dawn spacecraft acquired this picture on August 24, 2016. The image was taken during Dawn’s extended mission, from its low altitude mapping orbit at about 240 miles (385 kilometers) above the surface. The center coordinates of this image are 38 degrees south latitude, 165 degrees east longitude.

Fly Overs

There are two, first New Horizons over Pluto:

And second, a flyover of Charon:

NASA (via YouTube) – Using actual New Horizons data and digital elevation models of Pluto and its largest moon Charon, mission scientists have created flyover movies that offer spectacular new perspectives of the many unusual features that were discovered and which have reshaped our views of the Pluto system – from a vantage point even closer than the spacecraft itself.

Ceres at Opposition

Ceres diameter:  945 km / 587 miles.  Ceres is estimated to contain almost a third of mass of the entire asteroid belt.  Those movies with the spaceship having to do thrilling flying to get through the asteroid belt are far from being accurate.

NASA – This enhanced color image of Ceres’ surface was made from data obtained on April 29, 2017, when NASA’s Dawn spacecraft was exactly between the sun and Ceres. Dawn’s framing cameras took images of Ceres with a clear filter as well as five different color filters.

Images combining these different color filter perspectives reveal fine details of Ceres’ surface. For example, they emphasize the distinct compositions and textures of the material ejected from craters. The brightest region on Ceres, called Cerealia Facula, is highlighted in Occator Crater in the center of this image. Vinalia Faculae, the set of secondary bright spots in the same crater, are located to the right of Cerealia Facula.

One of the darkest regions on Ceres is next to Occator, and represents ejected material from the impact that formed the crater. The ejected material forms a large arc that extends over several hundred kilometers, below the center of Ceres in this image. That material’s distribution is partly determined by Ceres’ rotation.

Other craters also show a mixture of bright and dark regions. While the bright areas are generally identified as salt-rich material excavated from Ceres’ crust, the origin of the dark material remains to be explained. It may have been excavated from a different layer within Ceres’ subsurface than the rest of the ejecta blanket. Scientists will continue analyzing the color data to look for clues about the nature of the different materials on Ceres.

The blueish color is generally found in association with young craters. Scientists believe the color relates to processes that occur when an impact ejects and redistributes material on the surface. The continuous bombardment of Ceres’ surface by micrometeorites alters the texture of the exposed material, leading to its reddening.

This image was taken altitude of about 12,000 miles (20,000 kilometers). See the Dawn Journal for more detail about this opposition observation.

For more information about the Dawn mission, visit http://dawn.jpl.nasa.gov.

Image Credit:  NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

 

NavCam View of Ceres

A very nice look at Ceres from Dawn’s NAVCAM. The bright spot in Occator Crater at the top of the image.

The Dawn spacecraft is moving to a new orbit 20,000 km / 12,400 miles above Ceres, this image was taken on 28 March 2017 at a distance of 48,300 km / 30,000 miles. Dawn should be in place by the end of the month.

From NASA:
Several familiar features can be identified: At the top, we see Occator Crater and its faculae (bright deposits identified as a mixture of sodium carbonate and other salts). Below center is the crater Urvara, and to the right of it, the larger crater Yalode (the third and second largest craters on Ceres, respectively). Large-scale faults called Samhain Catenae stretch from the Occator region toward the Yalode-Urvara region.

This map can be used to locate these and more features. (Link goes off-site, use your back button to return)

Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

 

Dawn’s Look at Ceres

The Dawn spacecraft returned this very nice image of the dwarf planet Ceres. It features Occator Crater and Ahuna Mons.

Ahuna Mons is the tallest mountain on Ceres, some 4 km / 2.5 miles high, it is visible on the right limb of the planet. Occator Crater is hard to miss with the bright evaporite deposits at the crater’s center and along the floor.

According to NASA both features are relatively young, share a similar composition — different from Ceres’ average composition — and hint at recent internal activity in the dwarf planet. Cere’s is a mysterious place.

Dawn took this image during its third extended-mission science orbit (XMO3), from a distance of about 4,700 miles (7,500 kilometers) above the surface of Ceres. The image resolution is about 2,300 feet (700 meters) per pixel.

Image: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Fly Over Occator

Thanks the the Dawn spacecraft we can take a “fly-over” of Occator crater on the dwarf-planet Ceres. The bight areas are may have been produced by upwelling of salt-rich liquids after the impact that formed the crater.

The animation was produced by the German Aerospace Center (DLR). Original music by Stefan Elgner, DLR.

Video – JPL / NASA

Yalode Crater

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It’s all about perspective.

Original caption:
Sunlit cliffs tower above Yalode Crater on Ceres in this shadowy perspective view. At 152 miles (260 kilometers) in diameter, Yalode is one of Ceres’ largest craters. A fissure called Nar Sulcus is seen just right of center.

Dawn took this image on Oct. 19, 2016, 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.

A different view of Yalode, taken almost exactly one year prior, can be seen by clicking the image.

Images: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Ceres in Color

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Great look at Ceres, click the image to see a larger version.

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. — NASA

Image: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Occator Crater Viewed Again

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The Dawn spacecraft is still orbiting the dwarf planet Ceres and delivering great results.  This view of Occator Crater was taken on 18 October 2016 and highlights the area around the bright salt exposures.

From NASA/Dawn:

This image from NASA’s Dawn spacecraft shows Occator Crater on Ceres, with its signature bright areas. Dawn scientists have found that the central bright spot, which harbors the brightest material on Ceres, contains a variety of salts. The brightest parts of these features are overexposed in this image, which had an exposure time intended to capture details in the surrounding terrain. Shorter exposures allow details within the brightest areas to be seen, as in PIA20653.

Dawn took this image on Oct. 18, 2016, 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.

Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA