Posted on by Nancy Atkinson

Dawn’s Parting Shots of Vesta

Dawn’s look at asteroid Vesta as the spacecraft heads off to Ceres. Image credit: NASA/JPL-Caltech/UCAL/MPS/DLR/IDA

As Dawn says goodbye to Vesta — where the spacecraft has been orbiting for over a year — here are two final views of the giant asteroid, which are among the last taken by the spacecraft, NASA said.

“Dawn has peeled back the veil on some of the mysteries surrounding Vesta, but we’re still working hard on more analysis,” said Christopher Russell, Dawn’s principal investigator at UCLA. “So while Vesta is now out of sight, it will not be out of mind.”

The first is a black-and-white mosaic that shows a full view of the giant asteroid, created by synthesizing some of Dawn’s best images.

Below is a color-coded relief map of Vesta’s northern hemisphere, from the pole to the equator. It incorporates images taken just as Dawn began to creep over the high northern latitudes, which were dark when Dawn arrived in July 2011.

These color-shaded relief maps show the northern and southern hemispheres of Vesta, derived from images analysis. Colors represent distance relative to Vesta’s center, with lows in violet and highs in red. In the northern hemisphere map on the left, the surface ranges from lows of minus 13.82 miles (22.24 kilometers) to highs of 27.48 miles (44.22 kilometers). Light reflected off the walls of some shadowed craters at the north pole (in the center of the image) was used to determine the height. In the southern hemisphere map on the right, the surface ranges from lows of minus 23.65 miles (38.06 kilometers) to 26.61 miles (42.82 kilometers).

The shape model was constructed using images from Dawn’s framing camera that were obtained from July 17, 2011, to Aug. 26, 2012. The data have been stereographically projected on a 300-mile-diameter (500-kilometer-diameter) sphere with the poles at the center.

The three craters that make up Dawn’s “snowman” feature can be seen at the top of the northern hemisphere map on the left. A mountain more than twice the height of Mount Everest, inside the largest impact basin on Vesta, can be seen near the center of the southern hemisphere map on the right.

These images are the last in Dawn’s Image of the Day series during the cruise to Ceres. A full set of Dawn data is being archived at http://pds.nasa.gov/ .

Posted on by Nancy Atkinson

Wanted: Asteroid Mappers to Help Scientists Delve Through Data from Dawn

Many types of craters are captured in this panorama of recent Dawn images. Credit: NASA

There’s a new citizen science project in town, and this one will allow you to be among the first to see high-resolution, stunning images of Vesta from the Dawn mission. Called AsteroidMappers, the project asks the public to help the Dawn mission scientists to identify craters, boulders and other features on Vesta’s surface. “If you’ve already been addicted to MoonMappers, you’ll be even more addicted to AsteroidMappers!”said Nicole Gugliucci from CosmoQuest, home to several citizen science projects.

As you know, Dawn has been in orbit of the asteroid Vesta, but just recently left orbit and is now on its way to Ceres. This is a first in space exploration, where a spacecraft orbits one body and then leaves to go on to another. This can only be accomplished because of Dawn’s revolutionary ion engine.

The goal of the Dawn mission is to characterize the conditions and processes of the solar system’s earliest epoch by investigating in detail two of the largest protoplanets remaining intact since their formations. Ceres and Vesta both reside in the asteroid belt, but yet each has followed a very different evolutionary path constrained by the diversity of processes that operated during the first few million years of solar system evolution.

Even the Dawn scientists have been amazed at what they’ve seen at Vesta.

“We have acquired so much more data than we had planned even in late 2011,” Dr. Marc Rayman, the mission’s Chief Engineer, told Universe Today in a previous article. “We have conducted a tremendous exploration of Vesta – the second most massive body between Mars and Jupiter, a giant of the main asteroid belt.”

With AsteroidMappers (Vesta Edition), you’ll be helping the Dawn scientists learn more – not only about Vesta, but about how our solar system evolved.

As with every CosmoQuest project, there is a tutorial to help you get started. But the work area is fairly intuitive, with instructions and hints along the way.

The Dawn scientists have not yet released to the public all the images, so by working on this citizen science project, you’ll be looking at pristine images that perhaps no one else has seen before. The images are absolutely beautiful, as Vesta has turned out to be even more fascinating than expected, with huge impact basins, steep cliffs and unusual features on its surface.

“Vesta is unlike any other object we’ve visited in the solar system,” said Dawn mission team member Vishnu Reddy. “We see a wide range of variation on the surface, with some areas bright as snow, and other areas as dark as coal.”

Scientists have said that Vesta more closely resembles a small planet or Earth’s Moon than another asteroid, and they now have a better understanding of both Vesta’s surface and interior, and can conclusively link Vesta with meteorites that have fallen on Earth.

So, check out AsteroidMappers and enjoy the views! As @therealjason said on Twitter, “I don’t map Vesta very often, but when I do, I choose @cosmoquestX – Stay curious, my friends.”

Learn more about the Dawn mission here.

Posted on by Nancy Atkinson

On to Ceres: Dawn Spacecraft Ready to Say Farewell to Asteroid Vesta

Artist's conception of the Dawn mission. Credit: NASA

The feat has never been accomplished before and next week’s departure for the Dawn spacecraft from Vesta will be monumental. Dawn is on track to become the first probe to orbit and study two distant solar system destinations. The spacecraft is scheduled to leave the giant asteroid Vesta on Sept. 4 PDT (Sept. 5 EDT) to start its two-and-a-half-year journey to the dwarf planet Ceres.

“Thrust is engaged, and we are now climbing away from Vesta atop a blue-green pillar of xenon ions,” said Marc Rayman, Dawn’s chief engineer and mission director. “We are feeling somewhat wistful about concluding a fantastically productive and exciting exploration of Vesta, but now have our sights set on dwarf planet Ceres.

In the video above, the Dawn team looks back at the highlights of the year-plus stay in orbit around Vesta. Dawn’s orbit provided close-up views of Vesta, revealing unprecedented detail about the giant asteroid. The mission revealed that Vesta completely melted in the past, forming a layered body with an iron core. The spacecraft also revealed the scarring from titanic collisions Vesta suffered in its southern hemisphere, surviving not one but two colossal impacts in the last two billion years. Without Dawn, scientists would not have known about the dramatic troughs sculpted around Vesta, which are ripples from the two south polar impacts.

“We went to Vesta to fill in the blanks of our knowledge about the early history of our solar system,” said Christopher Russell, Dawn’s principal investigator, based at the University of California Los Angeles (UCLA). “Dawn has filled in those pages, and more, revealing to us how special Vesta is as a survivor from the earliest days of the solar system. We can now say with certainty that Vesta resembles a small planet more closely than a typical asteroid.”

Dawn arrived at Vesta in July 2011 and will reach Ceres in early 2015. Dawn’s targets represent two icons of the asteroid belt that have been witness to much of our solar system’s history.

NASA’s Dawn spacecraft arrived at the giant asteroid Vesta on July 15, 2011 PDT (July 16, 2011 EDT) and is set to depart on Sept. 4, 2012 PDT (Sept. 5 EDT). Image credit: NASA/JPL-Caltech

To make its escape from Vesta, the spacecraft will spiral away as gently as it arrived, using a special, hyper-efficient system called ion propulsion. Dawn’s ion propulsion system uses electricity to ionize xenon to generate thrust. The 12-inch-wide ion thrusters provide less power than conventional engines, but can maintain thrust for months at a time.

For a second time, we wish Dawn Bon Voyage!

Source: JPL

Posted on by Nancy Atkinson

Vesta’s Amazing Technicolor Surface

A brand new 3-D video map from the Dawn mission provides a unique view of the varied surface of the giant asteroid Vesta. The animation drapes high-resolution false color images over a 3-D model of the Vesta terrain constructed from Dawn’s observations. This visualization enables a detailed view of the variation in the material properties of Vesta in the context of its topography.
Continue reading “Vesta’s Amazing Technicolor Surface”

Posted on by Jason Major

The Bright and Dark Side of Vesta’s Craters

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Bright craters, dark craters… craters shaped like butterflies… they’re all represented here in a panorama made from images acquired by NASA’s Dawn spacecraft, currently in orbit around the asteroid Vesta.

I stitched two images together (using a third for gap fill-in) that were originally acquired by Dawn’s framing camera in October 2011 and released last week. Because the angle of sunlight is pretty close to straight-on, there’s not a whole lot of relief in the original images so I bumped that contrast up a bit as well, to help bring out Vesta’s terrain.

The dark crater in the center is Laelia, and it’s surrounded by smaller dark impact craters as well… most notably one that displays dramatic rays of dark material. At top right is the much larger crater Sextilia, which has bright material revealed along its inner rim.

Near the lower left edge, just horizontal from Laelia, is the butterfly-shaped Helena crater. It shows both bright and dark material, the latter of which can be seen slumping into the crater as well as outward from its rim. Helena is approximately 22 kilometers (14 miles) in diameter. (There’s a scale at the lower right showing a 10-km / 6.2-mile-wide span.)

The images were acquired during the HAMO (high-altitude mapping orbit) phase of the mission.

On Thursday, May 10, NASA will host a news conference at 11 a.m. PDT (2 p.m. EDT) to present a new analysis of the giant asteroid Vesta using data from the agency’s Dawn spacecraft. The event will be broadcast live on NASA Television and streamed on the agency’s website. For streaming video, downlink and scheduling information visit: http://www.nasa.gov/ntv.

The event will also be streamed live on Ustream with a moderated chat available at http://www.ustream.com/nasajpl2. Questions may also be asked via Twitter using the hashtag #asknasa.The event will be held at NASA Headquarters in Washington, broadcast live on NASA Television and streamed on the agency’s website. For NASA TV streaming video, downlink and scheduling information, visit: http://www.nasa.gov/ntv.

Image credit: NASA/ JPL-Caltech/ UCLA/ MPS/ DLR/ IDA. Edited by J. Major.

This artist's concept shows NASA's Dawn spacecraft orbiting the giant asteroid Vesta. (NASA/JPL-Caltech)
Posted on by Jason Major

By Dawn’s Early Light

Vesta's surface textures get highlighted by dawn's light

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Sunrise on Vesta highlights the asteroid’s varied surface textures in this image from NASA’s Dawn spacecraft, released on Monday, Feb. 20. The image was taken on Dec. 18 with Dawn’s Framing Camera (FC).

Just as the low angle of  early morning sunlight casts long shadows on Earth, sunrise on Vesta has the same effect — although on Vesta it’s not trees and buildings that are being illuminated but rather deep craters and chains of pits!

The steep inner wall of a crater is seen at lower right with several landslides visible, its outer ridge cutting a sharp line.

Chains of pits are visible in the center of the view. These features are the result of ejected material from an impact that occurred outside of the image area.

Other lower-profile, likely older craters remain in shadow.

Many of these features would appear much less dramatic with a high angle of illumination, but they really shine brightest in dawn’s light.

See the full image release on the Dawn mission site here.

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

Posted on by Jason Major

Asteroid’s Unusual Light and Dark Crater

A 5-km-wide crater on Vesta displays light and dark material.

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Light and dark material spreads outward from a 5-km-wide crater on Vesta in this image from NASA’s Dawn spacecraft, acquired on October 22, 2011. While craters with differently-toned materials have been previously seen on the asteroid, it is unusual to find one with such a large amount of ejecta of different albedos.

This is a crop of a larger version which was released today on the Dawn website.

This brightness image was taken through the clear filter of Dawn’s framing camera. The distance to the surface of Vesta is 700 kilometers (435 miles) and the image has a resolution of about 70 meters (230 feet) per pixel.

Orbit map: Where is Dawn now?

Vesta resides in the main asteroid belt between the orbits of Mars and Jupiter and is thought to be the source of many of the meteorites that fall to Earth. The Dawn spacecraft successfully entered orbit around Vesta on July 16, 2011.

After its investigation of Vesta, Dawn will leave orbit and move on to Ceres. It will become the first spacecraft to orbit two different worlds.

Image Credit: NASA/ JPL-Caltech/ UCLA/ MPS/ DLR/ IDA
Posted on by Nancy Atkinson

Looming Larger: Dawn Approaches Vesta, Enters Orbit July 15-16

NASA's Dawn spacecraft obtained this image of the giant asteroid Vesta with its framing camera on July 9, 2011. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

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As we anticipate the Dawn spacecraft going into orbit of Vesta within the next 36 hours, here’s the latest image taken as the spacecraft approaches Vesta, taken on July 9 from a distance of about 41,000 kilometers (26,000 miles). Surface details are coming into focus a little more than from the previous image that was released. The Dawn mission is exciting, as it will be the first spacecraft to enter orbit around a main-belt asteroid, and as we’ve said before, it will be intriguing for scientists to study this lumpy little world in detail and perhaps figuring out what Vesta really is.

Below is an “enhanced” look at this view of Vesta by Stu Atkinson.

Some astronomers classify Vesta as an asteroid, some a protoplanet, and some are on the fence. It’s not really considered a dwarf planet, but the classification could be re-evaluated when Dawn gets in orbit of Vesta and studies it in detail.

An enhanced view of Vesta from the July 9, 2011 image taken by the Dawn spacecraft. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA, enhancements by Stu Atkinson.

Stu sent us this image with the caveat that he created it for his own amusement/entertainment, and that it’s not a scientifically enhanced image — i.e., it’s not to be 100% relied upon for feature identification, etc. But it’s a little clearer and sharper than the original from NASA/JPL. Thanks Stu!

Engineers expect the spacecraft to be captured into orbit at approximately 10 p.m. PDT Friday, July 15 (1 a.m. EDT Saturday, July 16). They expect to hear from the spacecraft and confirm that it performed as planned during a scheduled communications pass that starts at approximately 11:30 p.m. PDT on Saturday, July 16 (2:30 a.m. EDT Sunday, July 17). When Vesta captures Dawn into its orbit, engineers estimate there will be approximately 9,900 miles (16,000 kilometers) between the spacecraft and Vesta. At that point, the two will be approximately 117 million miles (188 million kilometers) from Earth.

“It has taken nearly four years to get to this point,” said Robert Mase, Dawn project manager at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “Our latest tests and check-outs show that Dawn is right on target and performing normally.”

Engineers have been subtly shaping Dawn’s trajectory for years to match Vesta’s orbit around the sun with its ion engine. Unlike other missions, where dramatic propulsive burns put spacecraft into orbit around a planet, Dawn will ease up next to Vesta. Then the asteroid’s gravity will capture the spacecraft into orbit. However, until Dawn nears Vesta and makes accurate measurements, the asteroid’s mass and gravity will only be estimates. So the Dawn team will need a few days to refine the exact moment of orbit capture.

Launched in September 2007, Dawn will depart for its second destination, the dwarf planet Ceres, in July 2012. The spacecraft will be the first to orbit two bodies in our solar system.

Stay tuned for more details and updates on the Dawn mission.

Source: JPL

Posted on by Nicholos Wethington

Dawn Takes up Residence in Asteroid Belt

The Dawn spacecraft – which is on a course to study the asteroid Vesta and dwarf planet Ceres – has taken up permanent residence in the asteroid belt as of November 13th. Dawn is officially the first human-made object to become a part of the asteroid belt, which is sandwiched between the orbits of Mars and Jupiter.Dawn didn’t move in without checking the place out first, though; this is the second visit for the craft, which remained there for 40 days in June of 2008. The lower boundary of the asteroids belt is defined as the furthest Mars gets away from the Sun during its orbit – 249,230,000 kilometers, or 154,864,000 miles.

Dawn, which was launched in September 2007, is on an eight-year, 4.9-billion kilometer (3-billion mile) journey to study the asteroid Vesta and the dwarf planet Ceres. By studying these members of the asteroid belt, NASA scientists hope to learn more about the formation of our Solar System. Because Vesta and Ceres are some of the largest members of the ring of asteroids between Mars and Jupiter, they are the most intact from when they were formed, and should act as a ‘time capsule’ to preserve information about what the early Solar System was like.

Dawn got a gravity assist from Mars in February of 2009, which propelled it past the planet and into the asteroid belt.

The spacecraft is expected to visit Vesta in August of 2011. Vesta is believed to be the source of most of the asteroid-origin meteorites that fall to ground here on Earth, and further study of the asteroid should confirm this.

In May of 2012, Dawn will make its way to Ceres, which lies further out in the asteroid belt. It will arrive there in July of 2015, where it will spend the remainder of its mission studying the icy dwarf planet, which may even have a tenuous atmosphere.

If you want to keep tabs on Dawn in its new home, the mission web site has a tool updated hourly, found here, which allows you to see where Dawn is right now. The tool includes simulated views of the Earth, Mars, Sun and Vesta from the vantage point of the spacecraft.

Source: JPL