Thursday, August 23, 2018

Dawn Gathers More Spectacular Close Up Imagery of Ceres Bright Spots as Mission Nears Conclusion

Wide view high resolution mosaic of the side by side Cerealia Facula (left) and Vinalia Faculae (right) features shows the famous bright spots of salt deposits inside Occator Crater on Ceres. It is based on images obtained by NASA's Dawn spacecraft in its second extended mission, from an altitude as low as about 21 miles (34 kilometers) since June 2018. This stitched mosaic reveals the intricate pattern between bright and dark material across these flow features, which scientists will use to infer the history of this area, in particular the role of the fractures in the exposure of bright salts onto the surface.  Credits: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/Ken Kremer/kenkremer.com/Marco Di Lorenzo
Ken Kremer  --   SpaceUpClose.com  --   21 August 2018

CAPE CANAVERAL, FL –  NASA’s groundbreaking Dawn spacecraft continues to gather additional spectacular close up imagery of the remarkable and famous bright spots and craters on dwarf planet Ceres as the mission nears the conclusion of its amazing 11-year trek.

The bright spots are mostly composed of sodium carbonate and ammonium chloride that somehow spouted as slushy brines and leaked their way to the surface forming impressive and unique salt mounds and spots on the rugged Cerean surface. 

The famous and mysterious brights spots of Occator Crater are a particular focus of Dawn’s last orbits zeroing in on the Cerealia Facula and Vinalia Faculae fracture features of salt deposits.

The pair of prominent spots looked like a pair of eyes staring out eerily from Ceres surface from a distance before Dawn achieved orbit back in 2015. 

The imaging team of Ken Kremer and Marco Di Lorenzo has combined the new individual images of  taken by Dawn’s framing camera into a series of mosaics for Space UpClose - see above and herein.
This mosaic of a prominent mound located on the western side of Cerealia Facula showing famous bright spots of salt deposits inside Occator crater was newly obtained by NASA's Dawn spacecraft on June 22, 2018 from a record low altitude of about 21 miles (34 kilometers) above Ceres, colorized mosaic.  Credits: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/Ken Kremer/kenkremer.com/Marco Di Lorenzo


Dawn is currently flying around Ceres in a highly elliptical orbit and enjoying huge success in its second extended mission - as it captures the highest resolution images ever taken of the dwarf plant as well as the final series of close up imagery and spectral data on its elemental and chemical composition with a trio of science instruments.  

The new imagery reveals new insights into the origin and evolution of the mysterious alien world – which is the largest object located in the main Asteroid Belt between Mars and Jupiter.  



This context collage shows the location of a prominent mound of the famous bright spots of salt deposits located on the western side of Cerealia Facula (upper & lower right) and Vinalia Faculae (lower left) and inside Occator crater (upper left) on dwarf planet Ceres. Newly obtained highest ever resolution images were taken of the bright salt deposits inside Occator by NASA's Dawn spacecraft on June 22, 2018 from a record low altitude of about 21 miles (34 kilometers) above Ceres, colorized mosaics.  Credits: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/Ken Kremer/kenkremer.com/Marco Di Lorenzo
"The new images of Occator Crater and the surrounding areas have exceeded expectations, revealing beautiful, alien landscapes," said Carol Raymond of JPL, principal investigator of the Dawn mission.

Occator Crater is an impact crater measuring 57 miles (92 kilometers) across and 2.5 miles (4 kilometers) deep.
This context collage shows the location of a prominent mound of the famous bright spots of salt deposits located on the western side of Cerealia Facula (top right) inside Occator crater (left) on dwarf planet Ceres. Newly obtained highest ever resolution images were taken of the bright salt deposits inside Occator by NASA's Dawn spacecraft since June 2018 from a record low altitude of about 21 miles (34 kilometers) above Ceres, colorized mosaics.  Credits: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/Ken Kremer/kenkremer.com/Marco Di Lorenzo


"Ceres' unique surface appears to be shaped by impacts into its volatile-rich crust, resulting in intriguing, complex geology, as we can see in the new high-resolution mosaics of Cerealia Facula and Vinalia Faculae."

This second extended mission also marks Dawn’s final orbit and eternal resting place - ranging from a high of about 2,500 miles (4,000 kilometers) and diving down to only 22 miles (35 kilometers) about once per day.   For context that’s about three times the altitude of a passenger jet routinely flying on Earth.


The long-lived spacecraft reached this final orbit in early June and is gathering exquisitely detailed imagery and collecting high resolution spectral composition measurements involving gamma ray and neutron spectra, infrared and visible spectra, and gravity data. 


Dawn’s observations focus on the area around Occator and Urvara craters, with “the main goal of understanding the evolution of Ceres, and testing for possible ongoing geology.”

“NASA’s Dawn spacecraft reached its lowest-ever and final orbit around dwarf planet Ceres on June 6 and has been returning thousands of stunning images and other data,” NASA said in a statement.


“Besides the high-resolution images, the spacecraft is collecting gamma ray and neutron spectra, infrared and visible spectra, and gravity data. The observations focus on the area around Occator and Urvara craters, with the main goal of understanding the evolution of Ceres, and testing for possible ongoing geology.” 



This context collage displays locations of a variety of bright spots of salt deposits and mounds inside Occator crater on dwarf planet Ceres. Newly obtained highest ever resolution images were taken by NASA's Dawn spacecraft since June 2018 from a record low altitude of about 21 miles (34 kilometers) above Ceres.  Credits: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/Ken Kremer/kenkremer.com/Marco Di Lorenzo
The fuel supply of hydrazine is very low and could run out anytime over the next few months - between now and October. 

Engineers can’t say precisely how long since there is no fuel gauge in the storage to measure what remains. Its all based on mission long calculations of fuel expenditures – which is an imprecise art.  

“Within a few months, Dawn is expected to run out of a key fuel, hydrazine, which feeds thrusters that control its orientation and keeps it communicating with Earth. When that happens, sometime between August and October, the spacecraft will stop operating, but it will remain in orbit around dwarf planet Ceres,” according to NASA. 

It reached orbit around Ceres in 2015 and has gathered hundreds of thousands of images and measurements ever since.  

“At Ceres, the spacecraft discovered brilliant, salty deposits decorating the dwarf planet like a smattering of diamonds. The science behind these bright spots is even more compelling: they are mainly sodium carbonate and ammonium chloride that somehow made their way to the surface in a slushy brine from within or below the crust.” 


Occator Crater, measuring 57 miles (92 kilometers) across and 2.5 miles (4 kilometers) deep, contains the brightest area on Ceres. This region has been the subject of intense interest since Dawn's approach to the dwarf planet in early 2015.  Credits: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

The new data will help scientists piece together the relationships between bright and dark materials on the floor of Occator Crater. It exhibits impact processes, landslides and cryovolcanism the source of the bright spots.

"Observations, modeling and laboratory studies helped us conclude that the bright spots are either formed by impacts interacting with the crust, or that a reservoir of briny melt contributed to their formation," said JPL Dawn scientist Jennifer Scully, in a statement concerning data presented at recent the Committee on SPAce Research (COSPAR) July 2018 meeting in Pasadena.

Dawn is the first spacecraft to orbit two worlds – enabled only by its unique ion propulsion thruster system which is vastly more powerful than chemical thrusters.

The spacecraft first studied Vesta for 14 months, the second most massive asteroid in 2011 and 2012. 

"Dawn's unique mission to orbit and explore two strange new worlds would have been impossible without ion propulsion," said Marc Rayman of NASA's Jet Propulsion Laboratory, Pasadena, California, who has served as Dawn's mission director, chief engineer and project manager. 

"Dawn is truly an interplanetary spaceship, and it has been outstandingly productive as it introduced these fascinating and mysterious worlds to Earth."

Dawn was built by Orbital ATK, now Northrup Grumman and launched on a ULA Delta II rocket from Florida. It swung by Mars before arriving at its first target, Vesta, the second most massive object in the asteroid belt. 

Watch for Ken’s continuing onsite coverage of NASA, SpaceX, ULA, Boeing, Lockheed Martin, Orbital ATK and more space and mission reports direct from the Kennedy Space Center, Cape Canaveral Air Force Station, Florida and Wallops Flight Facility, Virginia.

Stay tuned here for Ken's continuing Earth and Planetary science and human spaceflight news: www.kenkremer.com –www.spaceupclose.com – twitter @ken_kremer – email: ken at kenkremer.com

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