New image captures Ceres' bright spots as never seen before

Wednesday, September 9, 2015, 4:22 PM - New pictures from NASA's Dawn delivers the closest look yet at Ceres' bright spots, Saturn's weird warm ring, and three men prepare to plummet back to Earth. It's What's Up In Space!

Sharper focus for an enduring mystery

The level of detail NASA's Dawn spacecraft of the surface of dwarf planet Ceres is truly staggering, but even as the images capture the mysterious bright spots, scientists are still no closer to figuring out exactly what they are.

From just under 1,500 kilometres above the surface, Dawn snapped this photo of Occator crater on one of its most recent orbits. The Sun is behind the spacecraft and off to the right, throwing the right edge of the immense crater into shadow.

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

There is a rather striking fact about this image. At this distance, the spots are so bright in Dawn's camera that in order to present it to us in the above format, the Dawn team had to take two images - one quick exposure shot of the spots and another normal exposure image of their surroundings - and put them together in a composite. If they just took one image of the area, the spots would wash everything out so badly, we wouldn't be able to see any detail!

"Dawn has transformed what was so recently a few bright dots into a complex and beautiful, gleaming landscape," Marc Rayman, Dawn's chief engineer and mission director based at NASA's Jet Propulsion Laboratory, said in a statement. "Soon, the scientific analysis will reveal the geological and chemical nature of this mysterious and mesmerizing extraterrestrial scenery."

Saturn weird warm ring

Saturn, our solar system's "lord of the rings" has long fascinated astronomers, and while NASA's Cassini spacecraft has been returning data to answer many questions about the planet, its rings and moons, what scientists are seeing is also bringing up some new mysteries as well.

Cassini's view during Saturn's 2009 equinox, showing off the planet's innermost C-ring, the lighter B-ring in the middle, the darker A-ring and thin F-ring. Credit: NASA/JPL/Space Science Institute

Research led by Ryuji Morishima, of NASA's Jet Propulsion Laboratory, shows that Saturn's A-ring - the outermost region of the planet's main ring system - is apparently warmer than the rest of the rings.

"This particular result is fascinating because it suggests that the middle of Saturn's A ring may be much younger than the rest of the rings," study co-author Linda Spilker, a Cassini project scientist at JPL, said in a statement. "Other parts of the rings may be as old as Saturn itself."

According to NASA:

To address this curiosity, Morishima and colleagues performed a detailed investigation of how ring particles with different structures would warm up and cool down during Saturn's seasons. Previous studies based on Cassini data have shown Saturn's icy ring particles are fluffy on the outside, like fresh snow. This outer material, called regolith, is created over time, as tiny impacts pulverize the surface of each particle. The team's analysis suggested the best explanation for the A ring's equinox temperatures was for the ring to be composed largely of particles roughly 3 feet (1 meter) wide made of mostly solid ice, with only a thin coating of regolith.
"A high concentration of dense, solid ice chunks in this one region of Saturn's rings is unexpected," said Morishima. "Ring particles usually spread out and become evenly distributed on a timescale of about 100 million years."
The accumulation of dense ring particles in one place suggests that some process either placed the particles there in the recent geologic past or the particles are somehow being confined there. The researchers suggest a couple of possibilities to explain how this aggregation came to be. A moon may have existed at that location within the past hundred million years or so and was destroyed, perhaps by a giant impact. If so, debris from the breakup might not have had time to diffuse evenly throughout the ring. Alternatively, they posit that small, rubble-pile moonlets could be transporting the dense, icy particles as they migrate within the ring. The moonlets could disperse the icy chunks in the middle A ring as they break up there under the gravitational influence of Saturn and its larger moons.

The mystery of how this happened may persist for now, however Cassini's final mission may shed more light on this, as it uses gravity science to measure the mass of the rings for the first time. This will allow the science team to gauge the age of the rings, and test whether their assumptions are correct.

Leaving space behind in a plummet to Earth

Early Friday morning, Russian cosmonaut Gennady Padalka will leave behind his two crewmates - Scott Kelly and Mikhail Kornienko, who will continue their One Year Mission - to return to Earth with ESA astronaut Andreas Mogensen and Kazakhstani astronaut Aidyn Aimbetov.

The departure of the Soyuz from the International Space Station is scheduled for 5:29 p.m. EDT, Friday, September 11. At that time, it will uncouple from the station's docking collar and perform a series of burns that will have it plummet into Earth's atmosphere in a 3.5 hour drop to the surface.

WATCH BELOW: Expedition 41 undocks from the International Space Station in November of 2014.

The only safeguards to ensure a successful and safe landing are the parachutes that will deploy part-way through their journey, and the brief blast from the capsule's rockets just before touchdown, to slow them the final bit necessary for them to survive the landing. These systems are tried, tested and true, but it still makes for a dramatic ride home!

NASA TV is sure to feature live footage of the departure and landing, so stay tuned for upcoming coverage of the events.

Sources: NASA | NASA JPL | NASA ISS blog | NASA TV

Note: The third entry in this article originally stated that the Soyuz is scheduled to depart at 5:29 a.m. EDT on Friday. The latest press release from NASA now lists 5:29 p.m. EDT on Friday. The article has been changed to reflect this. We apologize for any confusion or inconvenience.

WATCH BELOW: Expedition 41 lands in the steppes of Kazakhstan only hours after departure from the International Space Station on November 9, 2014.