NASA Dawn Spacecraft captures new images of CERES craters

The Dawn spacecraft observed Ceres for an hour on Jan. 13, 2015, from a distance of 238,000 miles (383,000 kilometers). 

A little more than half of its surface was observed at a resolution of 27 pixels. 

This animated GIF shows bright and dark features. 

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

Latest image from Nasa's Dawn Spacecraft showing the craters on Ceres.

Credit: NASA

NASA's Dawn spacecraft has entered an approach phase in which it will continue to close in on Ceres, a Texas-sized dwarf planet never before visited by a spacecraft.

Dawn launched in 2007 and is scheduled to enter Ceres orbit in March 2015.

Dawn recently emerged from solar conjunction, in which the spacecraft is on the opposite side of the sun, limiting communication with antennas on Earth.

Now that Dawn can reliably communicate with Earth again, mission controllers have programmed the maneuvers necessary for the next stage of the rendezvous, which they label the Ceres approach phase.

Dawn is currently 400,000 miles (640,000 kilometers) from Ceres, approaching it at around 450 miles per hour (725 kilometers per hour).

The spacecraft's arrival at Ceres will mark the first time that a spacecraft has ever orbited two solar system targets.

NASA Dawn Spacecraft Begins Approach to Ceres

NASA's Dawn spacecraft has entered an approach phase in which it will continue to close in on Ceres, a Texas-sized dwarf planet never before visited by a spacecraft. Dawn launched in 2007 and is scheduled to enter Ceres orbit in March 2015.

Dawn recently emerged from solar conjunction, in which the spacecraft is on the opposite side of the sun, limiting communication with antennas on Earth.

Now that Dawn can reliably communicate with Earth again, mission controllers have programmed the maneuvers necessary for the next stage of the rendezvous, which they label the Ceres approach phase.

Dawn is currently 400,000 miles (640,000 kilometers) from Ceres, approaching it at around 450 miles per hour (725 kilometers per hour).

The spacecraft's arrival at Ceres will mark the first time that a spacecraft has ever orbited two solar system targets.

Dawn previously explored the protoplanet Vesta for 14 months, from 2011 to 2012, capturing detailed images and data about that body.

"Ceres is almost a complete mystery to us," said Christopher Russell, principal investigator for the Dawn mission, based at the University of California, Los Angeles.

"Ceres, unlike Vesta, has no meteorites linked to it to help reveal its secrets. All we can predict with confidence is that we will be surprised."

The two planetary bodies are thought to be different in a few important ways. Ceres may have formed later than Vesta, and with a cooler interior.

Current evidence suggests that Vesta only retained a small amount of water because it formed earlier, when radioactive material was more abundant, which would have produced more heat.

Ceres, in contrast, has a thick ice mantle and may even have an ocean beneath its icy crust.

The two planetary bodies are thought to be very different. Ceres has an average diameter of 950 km (590 miles) while Vesta has an average diameter of 525 km (326 miles).

Ceres may have formed later than Vesta, and have a cooler interior. Vesta formed earlier, when radioactive material was more abundant, which produced more heat so Vesta retained little water, whereas Ceres has a thick ice mantle and may even have an ocean beneath its icy crust.

Dawn is currently 640,000 km (400,000 miles) from Ceres, approaching it at around 725 km per hour (450 miles per hour).

Ceres is also the largest body in the asteroid belt, the strip of solar system real estate between Mars and Jupiter.

By comparison, Vesta has an average diameter of 326 miles (525 kilometers), and is the second most massive body in the belt.

The spacecraft uses ion propulsion to traverse space far more efficiently than if it used chemical propulsion. In an ion propulsion engine, an electrical charge is applied to xenon gas, and charged metal grids accelerate the xenon particles out of the thruster.

These particles push back on the thruster as they exit, creating a reaction force that propels the spacecraft. Dawn has now completed five years of accumulated thrust time, far more than any other spacecraft.

"Orbiting both Vesta and Ceres would be truly impossible with conventional propulsion. Thanks to ion propulsion, we're about to make history as the first spaceship ever to orbit two unexplored alien worlds," said Marc Rayman, Dawn's chief engineer and mission director, based at NASA's Jet Propulsion Laboratory in Pasadena, California.

The next couple of months promise continually improving views of Ceres, prior to Dawn's arrival. By the end of January, the spacecraft's images and other data will be the best ever taken of the dwarf planet.

Asteroid Vesta: The Best Geologic view

The new map of Vesta is a detailed geologic record of the asteroid.

Credit: NASA/JPL-Caltech/ASU

High-resolution new maps show the cratered, rocky surface of the huge asteroid Vesta in unprecedented detail, researchers say.

Images captured by NASA's Dawn spacecraft were woven together to create geologic maps of the giant asteroid Vesta.

The maps, the most detailed ones yet of of Vesta's surface features, serve as a geologic record of the asteroid that astronomers can compare to other planets and celestial bodies, researchers said.

Scientists combined 15 separate maps into one Vesta uber-map, which shows that meteorites have pummeled the asteroid since its formation about 10 million years after the birth of the solar system.

Astronomers can piece together Vesta's geologic timeline based on the sequence of meteorite impacts.


The brown colours on the map show the oldest and most heavily cratered areas on Vesta, while purple shows where Vesta was struck by two large impactors; the light purple and dark blue colors show the interior basins of the two massive impacts.

Greens and yellows show the youngest material on Vesta, which likely came from landslides or later meteorite strikes, researchers said.

A special camera onboard the Dawn spacecraft made the geologic maps possible. The camera uses seven different color filers that help analyze the different minerals covering Vesta's surface.

The photos were used to create 3D topographic models, which were then converted into maps of the surface.

It took over two years to sift through all the images and create the maps, said David Williams of Arizona State University, one of the lead scientists on the project.

The maps were published this week along with a series of papers in the journal Icarus.

NASA's Curiosity rover captures images of asteroids Ceres and Vesta

For the first time, NASA's Curiosity rover has captured images of an asteroid from the surface of Mars -- two of them, in fact.

The imagery recorded by Curiosity and beamed back to Earth feature Ceres and Vesta, two of the largest asteroids in the asteroid belt that runs between between Mars and Jupiter.

This Curiosity first was also a bit of a coincidence, as the SUV-sized rover had aimed its cameras at the Martian sky in order to snap shots of the Red Planet's two moons, not hunt for asteroids whizzing by.

"This imaging was part of an experiment checking the opacity of the atmosphere at night in Curiosity's location on Mars, where water-ice clouds and hazes develop during this season," camera team member Mark Lemmon, of Texas A&M University, explained in a statement.

"The two Martian moons were the main targets that night, but we chose a time when one of the moons was near Ceres and Vesta in the sky."

Mark Lemmon

NASA is currently on its way to get an even closer look at this two giant space rocks.

NASA's Dawn spacecraft orbited the 350-mile-wide Vesta asteroid in 2011 and 2012, and it is preparing to orbit the 590-mile-wide Ceres in 2015.