Posted on by Ken Kremer

NASA Planetary Science Trio Honored as ‘Best of What’s New’ in 2011- Curiosity/Dawn/MESSENGER

Popular Science magazine names NASA’s Mars Science Laboratory, Dawn and MESSENGER missions as ‘Best of What’s New’ in innovation in 2011. Artist concept shows mosaic of MESSENGER, Mars Science Laboratory and Dawn missions. Credit: NASA/JPL-Caltech

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A trio of NASA’s Planetary Science mission’s – Mars Science Laboratory (MSL), Dawn and MESSENGER – has been honored by Popular Science magazine and selected as ‘Best of What’s New’ in innovation in 2011 in the aviation and space category.

The Curiosity Mars Science Laboratory was just launched to the Red Planet on Saturday, Nov. 26 and will search for signs of life while traversing around layered terrain at Gale Crater. Dawn just arrived in orbit around Asteroid Vesta in July 2011. MESSENGER achieved orbit around Planet Mercury in March 2011.

Several of the top mission scientists and engineers provided exclusive comments about the Popular Science recognitions to Universe Today – below.

“Of course we are all very pleased by this selection,” Prof. Chris Russell, Dawn Principal Investigator, of UCLA, told Universe Today.


Dawn is the first mission ever to specifically investigate the main Asteroid Belt between Mars and Jupiter and will orbit both Vesta and Ceres – a feat enabled solely thanks to the revolutionary ion propulsion system.

“At the same time I must admit we are also not humble about it. Dawn is truly an amazing mission. A low cost mission, using NASA’s advanced technology to enormous scientific advantage. It is really, really a great mission,” Russell told me.

Vesta is the second most massive asteroid and Dawn’s discoveries of a surprisingly dichotomous and battered world has vastly exceeded the team’s expectations.

Asteroid Vesta from Dawn - Exquisite Clarity from a formerly Fuzzy Blob
NASA's Dawn spacecraft obtained this image of the giant asteroid Vesta with its framing camera on July 24, 2011. It was taken from a distance of about 3,200 miles (5,200 kilometers). Before Dawn, Vesta was just a fuzzy blob in the most powerful telescopes. Dawn entered orbit around Vesta on July 15, and will spend a year orbiting the body before firing up the ion propulsion system to break orbit and speed to Ceres, the largest Asteroid. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

“Dawn is NASA at its best: ambitious, exciting, innovative, and productive,” Dr. Marc Rayman, Dawn’s Chief Engineer from the Jet Propulsion Lab (JPL), Pasadena, Calif., told Universe Today.

“This interplanetary spaceship is exploring uncharted worlds. I’m delighted Popular Science recognizes what a marvelous undertaking this is.”

JPL manages both Dawn and Mars Science Laboratory for NASA’s Science Mission Directorate in Washington, D.C.

Dawn is an international science mission. The partners include the German Aerospace Center (DLR), the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute.

“Very cool!”, John Grotzinger, the Mars Science Laboratory Project Scientist of the California Institute of Technology, told Universe Today.

“MSL packs the most bang for the buck yet sent to Mars.”

Last View of Curiosity Mars Science Laboratory Rover - inside the Cleanroom at KSC.
Curiosity just before Encapsulation for 8 month long interplanetary Martian Journey and touchdown inside Gale Crater. Credit: Ken Kremer

Curiosity is using an unprecedented precision landing system to touch down inside the 154 km (96 miile) wide Gale Crater on Aug. 6, 2012. The crater exhibits exposures of phyllosilicates and other minerals that may have preserved evidence of ancient or extant Martian life and is dominated by a towering mountain.

“10 instruments all aimed at a mountain higher than any in the lower 48 states, whose stratigraphic layering records the major breakpoints in the history of Mars’ environments over likely hundreds of millions of years, including those that may have been habitable for life.”

“It’s like a trip down the Grand Canyon 150 years ago, with the same sense of adventure, but with a lot of high tech equipment,” Grotzinger told me.

MSL also has an international team of over 250 science investigators and instruments spread across the US, Europe and Russia.

Curiosity Mars Science Laboratory rover soars to Mars atop an Atlas V rocket on Nov. 26 at 10:02 a.m. EST from Cape Canaveral, Florida. Credit: Ken Kremer

MESSENGER is the first probe to orbit Mercury and the one year primary mission was recently extended by NASA.

Sean Solomon, of the Carnegie Institution of Washington, leads the MESSENGER mission as principal investigator. The Johns Hopkins University Applied Physics Laboratory built and operates the MESSENGER spacecraft for NASA.

“Planetary has 3 missions there… Dawn, MESSENGER, and MSL,” Jim Green proudly said to Universe Today regarding the Popular Science magazine awards. Green is the director, Planetary Science Division, NASA Headquarters, Washington

“Three out of 10 [awards] is a tremendous recognition of the fact that each one of our planetary missions goes to a different environment and takes on new and unique measurements providing us new discoveries and constantly changes how we view nature, ourselves, and our place in the universe.”

The First Solar Day
After its first Mercury solar day (176 Earth days) in orbit, MESSENGER has nearly completed two of its main global imaging campaigns: a monochrome map at 250 m/pixel and an eight-color, 1-km/pixel color map. Apart from small gaps, which will be filled in during the next solar day, these global maps now provide uniform lighting conditions ideal for assessing the form of Mercury’s surface features as well as the color and compositional variations across the planet. The orthographic views seen here, centered at 75° E longitude, are each mosaics of thousands of individual images. At right, images taken through the wide-angle camera filters at 1000, 750, and 430 nm wavelength are displayed in red, green, and blue, respectively.
Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Read more about the Popular Science citations and awards here
.
Read continuing features about Curiosity, Dawn and MESSENGER by Ken Kremer starting here:

Curiosity Mars Rover Launch Gallery – Photos and Videos
Curiosity Majestically Blasts off on ‘Mars Trek’ to ascertain ‘Are We Alone?
Dawn Discovers Surprise 2nd Giant South Pole Impact Basin at Strikingly Dichotomous Vesta
Amazing New View of the Mt. Everest of Vesta
MESSENGER Unveiling Mercurys Hidden Secrets

Posted on by Ken Kremer

Dawn Discovers Surprise 2nd Giant South Pole Impact Basin at Strikingly Dichotomous Vesta

Southern Hemisphere of Vesta; Rheasilvia and Older Basin. Colorized shaded-relief map showing identification of older 375-kilometer-wide impact basin beneath and overlapping with the more recent Rheasilvia impact structure at asteroid Vesta’s South Pole. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

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Scientists leading NASA’s Dawn mission have discovered a 2nd giant impact basin at the south pole of the giant asteroid Vesta, which has been unveiled as a surprisingly “dichotomous” and alien world. Furthermore, the cosmic collisions that produced these two basins shuddered through the interior and created vast Vestan troughs, a Dawn scientist told Universe Today.

The newly discovered impact basin, nicknamed ‘Older Basin’, is actually significantly older in age compared to the initially discovered South Pole basin feature named ‘Rheasilvia’ – perhaps by more than a billion years. And that is just one of the many unexplained mysteries yet to be reconciled by the team as they begin to sift through the millions of bits of new data streaming back daily to Earth.

Scientists speculate that ‘Older Basin’ is on the order of 3.8 Billion years old, whereas ‘Rheasilvia’ might be as young as about 2.5 Billion years, but those are just tentative estimates at this time and subject to change. Measurements so far indicate Rheasilvia is composed of basaltic material.

Shaded-relief topographic map of Vesta southern hemisphere showing two large impact basins - Rheasilvia and Older Basin.
Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

“We found many surprising things at Vesta, which is quite unique and the results have exceeded our expectations”, said Dr. Carol Raymond, Dawn deputy principal investigator, of NASA’s Jet Propulsion Laboratory, Pasadena, Calif.

Researchers presented the latest findings from Dawn’s initial science mapping orbit at a news briefing at the annual meeting of the Geological Society of America in Minneapolis, Minn., on Oct. 13.

The team considers Vesta to be the smallest terrestrial planet.

Since achieving orbit in July, Dawn’s Framing Cameras (FC) have imaged most of Vesta at about 250 meter resolution and the Visible and Infrared mapping spectrometer(VIR) at about 700 meter resolution. The measurements were collected at the survey orbit altitude of 2700 km. Before Dawn, Vesta was just a fuzzy blob in humankind’s most powerful telescopes.

Vesta from Hubble (top) as a fuzzy blob and from Dawn in orbit (bottom) in crystal clear high resolution.
Credit: NASA/JPL-Caltech/ UCLA/MPS/DLR/IDA

“There is a global dichotomy on Vesta and a fundamental difference between the northern and southern hemispheres”, said Raymond. “The northern hemisphere is older and heavily cratered in contrast to the brighter southern hemisphere where the texture is more smooth and there are lots of sets of grooves. There is a massive mountain at the South Pole. One of the more surprising aspects is the set of deep equatorial troughs.”

“There is also a tremendous and surprising diversity of surface color and morphology. The south is consistent with basaltic lithology and the north with impacts. We are trying to make sense of the data and will integrate that with the high resolution observations we are now collecting.”

Indeed Vesta’s completely unique and striking dichotomy can be directly traced back to the basins which were formed by ancient cataclysmic impacts resulting in shockwaves that fundamentally altered the surface and caused the formation of the long troughs that ring Vesta at numerous latitudes.

“The troughs extend across 240 degrees of longitude,” said Debra Buczkowski, Dawn participating scientist, of the Applied Physics Laboratory at Johns Hopkins University, Laurel, Md. “Their formation can be tied back to the two basins at the South Pole.”

Asteroid Vesta and Equatorial Grooves
This full view of the giant asteroid Vesta was taken by NASA’s Dawn spacecraft, as part of a rotation characterization sequence on July 24, 2011, at a distance of 3,200 miles (5,200 kilometers). A rotation characterization sequence helps the scientists and engineers by giving an initial overview of the character of the surface as Vesta rotated underneath the spacecraft. This view of Vesta shows impact craters of various sizes and grooves parallel to the equator. The resolution of this image is about 500 meters per pixel. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

In an exclusive follow up interview with Universe Today, Raymond said “We believe that the troughs formed as a direct result of the impacts,” said “The two sets of troughs are associated with the two large basins [Rheasilvia and Older Basin].”

“The key piece of evidence presented was that the set of troughs in the northern hemisphere, that look older (more degraded) are circumferential to the older impact basin,” Raymond told me.

“The equatorial set are circumferential to Rheasilvia. That Rheasilvia’s age appears in places to be much younger is at odds with the age of the equatorial troughs. An explanation for that could be resurfacing by younger mass wasting features (landslides, slumps). We will be working on clarifying all these relationships in the coming months with the higher resolution HAMO (High Altitude Mapping Orbit) data.”

Dawn has gradually spiraled down closer to Vesta using her exotic ion thrusters and began the HAMO mapping campaign on Sept. 29.

Surface features are dated by crater counting methodology.

“Preliminary crater counting age dates for the equatorial trough region yields a very old age (3.8 Billion years). So there is a discrepancy between the apparent younger age for the Rheasilvia basin and the old age for the troughs. These could be reconciled if Rheasilvia is also 3.8 Billion years old but the surface has been modified by slumping or other processes,” Raymond elaborated.

Time will tell as further data is analyzed.

Dawn launch on September 27, 2007 by a Delta II Heavy rocket from Cape Canaveral Air Force Station, Florida. Credit: Ken Kremer

“Vesta is full of surprises, no more so than at the South Pole,” said Paul Schenk at the GSA briefing. Schenk is a Dawn participating scientist of the Lunar and Planetary Institute, Houston, Texas.

The ‘Rheasilvia’ basin was initially discovered in images of Vesta taken a decade ago by the Hubble Space Telescope which revealed it as a gaping hole in the southern hemisphere. But it wasn’t until Dawn entered orbit on July 16, 2011 after a nearly four year interplanetary journey that Earthlings got their first close up look at the mysterious polar feature and can now scrutinize it in detail to elucidate its true nature.

“The South Pole [Rheasilvia] basin is a roughly circular, impact structure and a deep depression dominated by a large central mound,” said Schenk. “It shows sharp scarps, smooth areas, landslide deposits, debris flows. It’s about 475 km in diameter and one of the deepest (ca. 20 -25 km) impact craters in the solar system.”

The central peak is an enormous mountain, about 22 km high and 180 km across- one of the biggest in the solar system. “It’s comparable in some ways to Olympus Mons on Mars,” Schenk stated.

“We were quite surprised to see a second basin in the mapping data outside of Rheasilvia. This was unexpected. It’s called ‘Older Basin’ for now.”

‘Older Basin’ is about 375 km in diameter. They overlap at the place where Rheasilvia has a missing rim.

“These basins are interesting because we believe Vesta is the source of a large number of meteorites, the HED meteorites that have a spread of ages,” Schenk explained.

Images showing key components of Rheasilvia impact basin on Vesta in high resolution ,referred to Shaded-relief topographic map. Credit: NASA/JPL-Caltech/ UCLA/MPS/DLR/IDA

Multiple large impacts over time may explain the source of the HED (Howardite, Eucrite and Diogenite) meteorites.

“We did expect large impacts on Vesta, likely associated with the late heavy bombardment recognized in the lunar impact record,” Raymond told Universe Today. “The surprising element is that the two apparently largest impacts – keeping in mind that other larger impact basins may be lurking under the regolith – are overlapping.”

Dawn’s VIR spectrometer has detected pyroxene bands covering Vesta’s surface, which is indicative of typical basaltic material, said Federico Tosi, a VIR team member of the Italian Space Agency, Rome. “Vesta has diverse rock types on its surface.”

“VIR measured surface temperatures from 220K to 270 K at the 5 micron wavelength. The illuminated areas are warmer.”

So far there is no clear indication of olivine which would be a marker for seeing Vesta’s mantle, Tossi elaborated.

The VIR spectrometer combines images, spectral information and temperature that will allow researchers to evaluate the nature, composition and evolutionary forces that shaped Vesta’s surface.

The team is absolutely thrilled to see a complicated geologic record that’s been preserved for study with lots of apparent surface layering and surprisingly strong and complex structural features with a large range of color and brightness.

Stay tuned for a year of Vestan delights !

Asteroid Vesta from Dawn
South Pole Rheasilvia basin is at lower right. NASA's Dawn spacecraft obtained this image of the giant asteroid Vesta with its framing camera on July 24, 2011 from a distance of about 3,200 miles (5,200 kilometers). Dawn entered orbit around Vesta on July 16, and will spend a year orbiting the body.
Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Read Ken’s continuing features about Dawn and Vesta starting here:
Amazing New View of the Mt. Everest of Vesta
Dramatic 3 D Imagery Showcases Vesta’s Pockmarked, Mountainous and Groovy Terrain
Rheasilvia – Super Mysterious South Pole Basin at Vesta
Space Spectacular — Rotation Movies of Vesta
3 D Alien Snowman Graces Vesta
NASA Unveils Thrilling First Full Frame Images of Vesta from Dawn
Dawn Spirals Down Closer to Vesta’s South Pole Impact Basin
First Ever Vesta Vistas from Orbit – in 2D and 3D
Dawn Exceeds Wildest Expectations as First Ever Spacecraft to Orbit a Protoplanet – Vesta

Posted on by Ken Kremer

Amazing New View of the Mt. Everest of Vesta

Oblique View of Vesta's South Polar Region - Rheasilvia. This image of the asteroid Vesta, calculated from a shape model, shows a tilted view of the topography of the south polar region. The image has a resolution of about 1,000 feet (300 meters) per pixel, and the vertical scale is 1.5 times that of the horizontal scale. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI

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NASA has just released an amazing new view of the mysterious south pole of Vesta that offers an oblique perspective view of the central mountain peak which is three times as high as Mt Everest. This topographic view , shown above,is completely unique to viewers from Earth and is provided courtesy of NASA’s exotic Dawn Asteroid Orbiter – newly arrived in July 2011.

The mountain peak rises about 15 miles (22 km) above the average height of the surrounding pockmarked terrain at Vesta’s south polar region – formally named Rheasilvia – and is located in the foreground, left side of the new image. A portion of the crater rim with a rather steep slope – known as a scarp – is seen at the right and may show evidence of Vestan landslides.

This oblique image derived from the on board Framing Camera was created from a shape model of the 530 km diameter asteroid. It has been flattened to remove the curvature of Vesta and has a vertical scale adjusted to 1.5 times that of the horizontal scale.

The origin of Vesta’s south polar region is hotly debated among the mission’s science team who will reveal their current theories at a briefing set for October 12 – watch for my upcoming report.

Dawn will remain in orbit at Vesta for 1 year until July 2012 and then fire up its revolutionary ion propulsion system to depart for Ceres, the largest Asteroid in the main belt between Mars and Jupiter.

Asteroid Vesta from Dawn
NASA's Dawn spacecraft obtained this image of the giant asteroid Vesta with its framing camera on July 24, 2011. It was taken from a distance of about 3,200 miles (5,200 kilometers). Dawn entered orbit around Vesta on July 15, and will spend a year orbiting the body. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Read Ken’s continuing features about Dawn and Vesta starting here
Dramatic 3 D Imagery Showcases Vesta’s Pockmarked, Mountainous and Groovy Terrain
Rheasilvia – Super Mysterious South Pole Basin at Vesta
Space Spectacular — Rotation Movies of Vesta
3 D Alien Snowman Graces Vesta
NASA Unveils Thrilling First Full Frame Images of Vesta from Dawn
Dawn Spirals Down Closer to Vesta’s South Pole Impact Basin
First Ever Vesta Vistas from Orbit – in 2D and 3D
Dawn Exceeds Wildest Expectations as First Ever Spacecraft to Orbit a Protoplanet – Vesta

Posted on by Ken Kremer

Dramatic 3 D Imagery Showcases Vesta’s Pockmarked, Mountainous and Groovy Terrain

3 D Anaglyph of Craters at Rheasilvia - the South Polar Region of Vesta. This 3-D image shows the topography, craters and grooves of Vesta’s south polar region obtained by the framing camera instrument aboard NASA’s Dawn spacecraft on Aug. 23 and 28, 2011. The image has a resolution of about 260 meters per pixel.

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Try not to plummet off a steep crater cliff or be buried under a landslide while gazing at the irresistibly alluring curves of beautiful Rheasilvia – the mythical mother of Romulus and Remus – whose found a new home at the South Pole of the giant Asteroid Vesta.

3 D is undoubtedly the best way to maximize your pleasure. So whip out your cool red-cyan anaglyph glasses to enhance your viewing experience of Rheasilvia, the Snowman and more – and maximize your enjoyment of this new 3 D collection showcasing the heavily cratered, pockmarked, mountainous and groovy terrain replete at Vesta.

3D Details of Wave-Like Terrain in the South Pole of Vesta
This image was obtained by NASA’s Dawn spacecraft from an orbit of about 1,700 miles (2,700 kilometers) above the surface of the giant asteroid Vesta. Topography in the area surrounding Vesta's south pole area shows impact craters, ridges and grooves. These images in 3D provide scientists with a realistic impression of the solid surface of the celestial body.
Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Can you find the location of the 3 D image above in the 2 D South Pole image below?

Scientists and mortals have been fascinated by the enormous impact crater Rheasilvia and central mountain unveiled in detail by NASA’s Dawn Asteroid Orbiter recently arrived at Vesta, the 2nd most massive object in the main asteroid belt. Ceres is the largest object and will be Dawn’s next orbital target in 2015 after departing Vesta in 2012.

3D - A Big Mountain at Asteroid Vesta’s South Pole
Scientists were fascinated by this enormous mound inside a big circular depression at the south pole- dubbed Rheasilvia. This stereo image was recorded from an altitude of about 1,700 miles (2,700 kilometers) above the surface and shows the structure of the mountain, displayed in the right half of this 3D image. The base of the mountain has a diameter of about 125 miles (200 kilometers), and its altitude above the surroundings is about 9 miles (15 kilometers). The vicinity of the peak of the mountain shows landslides that occurred when material from the flanks of the mountain were slipping down. Also visible are tectonic structures from tension in Vesta's crust. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

“Vesta is the smallest terrestrial planet in our Solar System”, said Chris Russell in an interview with Universe Today. “We do not have a good analog to Vesta anywhere else in the Solar System.”

And the best is yet to come. In a few days, Dawn begins snapping images from a much lower altitude at the HAMO mapping orbit of ca. 685 km vs the initial survey orbit of ca, 2700 km. where most of these images were taken.

Can you find the location of the 3 D South Pole images above in the 2 D South Pole image below?

Topography of Densely Cratered Deformed Terrain
This 3 D anaglyph image shows the topography of Vesta's densely cratered terrain obtained by the framing camera instrument aboard NASA's Dawn spacecraft on August 6, 2011. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Anaglyph of the ‘Snowman' Crater. This anaglyph image shows the topography of Vesta's three craters, informally named the "Snowman," obtained by the framing camera instrument aboard Dawn on August 6, 2011. The camera has a resolution of about 260 meters per pixel. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Vesta's Ancient, Cratered Surface in 3D
This image of the giant asteroid Vesta obtained by NASA's Dawn spacecraft shows the surface of the asteroid from an orbit of about 1,700 miles (2,700 kilometers) above the surface. Numerous impact craters illustrate the asteroid's violent youth. By counting craters on distinct geological surfaces scientists can deduce relative ages of the asteroid's surface. This 3D view provides scientists the opportunity to learn more about the morphology of craters on asteroids and physical properties of the material at Vesta's surface.. Image resolution is about 260 meters per pixel. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Viewing the South Pole of Vesta and Rheasilvia Impact Basin
This image obtained by Dawns framing camera shows the south pole of the giant asteroid Vesta. Scientists are discussing whether the Rheasilvia circular structure that covers most of this image originated by a collision with another asteroid, or by internal processes early in the asteroid's history. Images in higher resolution from Dawn's next lowered orbit might help answer that question. The image was recorded from a distance of about 1,700 miles (2,700 kilometers). The image resolution is about 260 meters per pixel. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Rhea Silvia, torso from the amphitheatre at Cartagena in Spain that was rediscovered in 1988. Rhea Silvia was the mother of Romulus and Remus, the mythical founders of Rome. Source: Wikipedia

Read Ken’s continuing features about Dawn and Vesta

Rheasilvia – Super Mysterious South Pole Basin at Vesta
Space Spectacular — Rotation Movies of Vesta
3 D Alien Snowman Graces Vesta
NASA Unveils Thrilling First Full Frame Images of Vesta from Dawn
Dawn Spirals Down Closer to Vesta’s South Pole Impact Basin
First Ever Vesta Vistas from Orbit – in 2D and 3D
Dawn Exceeds Wildest Expectations as First Ever Spacecraft to Orbit a Protoplanet – Vesta
Dawn Closing in on Asteroid Vesta as Views Exceed Hubble
Dawn Begins Approach to Asteroid Vesta and Snaps First Images
Revolutionary Dawn Closing in on Asteroid Vesta with Opened Eyes

Posted on by Ken Kremer

Rheasilvia – Super Mysterious South Pole Basin at Vesta is Named after Romulus and Remus Roman Mother

A False-Color Topography of Vesta's South Pole. This false-color map of the giant asteroid Vesta was created from stereo images obtained by the framing camera aboard NASA’s Dawn spacecraft. The image shows the elevation of surface structures with a horizontal resolution of about 750 meters per pixel. The terrain model of Vesta's southern hemisphere shows a big circular structure with a diameter of about 300 miles (500 kilometers), its rim rising above the interior of the structure for more than 9 miles (15 kilometers.) Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Video caption: Rheasilvia Impact Basin and Vesta shape model. This false-color shape model video of the giant asteroid Vesta was created from images taken by the framing camera aboard NASA’s Dawn spacecraft. Rheasilvia – South Pole Impact Basin – shown at bottom (left) and head on (at right). Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

‘Rheasilvia’ – that’s the brand new name given to the humongous and ever more mysterious South Pole basin feature being scrutinized in detail by Dawn, according to the missions top scientists in a Universe Today exclusive. Dawn is NASA’s newly arrived science orbiter unveiling the giant asteroid Vesta – a marvelously intriguing body unlike any other in our Solar System.

What is Rheasilvia? An impact basin? A crater remnant? Tectonic action? A leftover from internal processes? Or something completely different? That’s the hotly debated central question consuming loads of attention and sparking significant speculation amongst Dawn’s happily puzzled international science team. There is nothing closely analogous to Vesta and Rhea Silvia – and thats a planetary scientists dream come true.

“Rheasilvia – One thing that we all agree on is that the large crater should be named ‘Rheasilvia’ after the mother of Romulus and Remus, the mythical mother of the Vestals,” said Prof. Chris Russell, Dawns lead scientist, in an exclusive interview with Universe Today. Russell, from UCLA, is the scientific Principal Investigator for Dawn.

“Since we have never seen any crater just like this one it is difficult for us to decide exactly what did happen,” Russell told me. “The name ‘Rheasilvia’ has been approved by the IAU and the science team is using it.”

Craters on Vesta are being named after the Vestal Virgins—the priestesses of the Roman goddess Vesta. Other features will be named for festivals and towns of that era. Romulus and Remus were the mythical founders of Rome.
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‘Rheasilvia’ has the science team in a quandary, rather puzzled and reevaluating and debating long held theories as they collect reams of new data from Dawn’s three science instruments – provided by the US, Germany and Italy. That’s the scientific method in progress and it will take time to reach a consensus.

Prior to Dawn’s orbital insertion in July 2011, the best views of Vesta were captured by the Hubble Space Telescope and clearly showed it wasn’t round. Scientists interpreted the data as showing that Vesta’s southern hemisphere lacked a South Pole! And, that it had been blasted away eons ago by a gargantuan cosmic collision that excavated huge amounts of material that nearly utterly destroyed the asteroid.

The ancient collision left behind a colossal 300 mile (500 km) diameter and circular gaping hole in the southern hemisphere – nearly as wide as the entire asteroid (530 km) and leaving behind an as yet unexplained and enormous central mountain peak, measuring some 9 miles (15 km) high and over 125 miles (200 km) in diameter. The mountain has one of the highest elevations in the entire solar system.

“We are trying to understand the high scarps that we see and the scarps that should be there and aren’t,” Russell explained. “We are trying to understand the landslides we think we see and why the land slid. We see grooves in the floor of the basin and want to interpret them.

“And the hill in the center of the crater remains as mysterious today as when we first arrived.”

Viewing the South Pole of Vesta and Rheasilvia Impact Basin
This image obtained by Dawns framing camera and shows the south pole of the giant asteroid Vesta. Scientists are discussing whether the Rheasilvia circular structure that covers most of this image originated by a collision with another asteroid, or by internal processes early in the asteroid's history. Images in higher resolution from Dawn's lowered orbit might help answer that question. The image was recorded from a distance of about 1,700 miles (2,700 kilometers). The image resolution is about 260 meters per pixel. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Another top Dawn scientist described Rheasilvia in this way:

“I would say that the floor of the impact feature contains chaotic terrain with multiple sets of intersecting grooves, sometimes fairly straight and often curvy, said Carol Raymond to Universe Today. Raymond is Dawn’s Deputy Principal Investigator from NASA’s Jet Propulsion Laboratory in Pasadena, Calif.

“The crater rim is not well-expressed”, Raymond told me. “We see strong color variations across Vesta, and the south pole impact basin appears to have a distinct spectral signature.

“The analysis is still ongoing,” Russell said.


“The south is distinctly different than the north. The north has a varied spectrum and the south has a distinct spectral feature but it has little variation.” Time will tell as additional high resolution measurements are collected from the forthcoming science campaign at lower orbits.

Russell further informed that the team is rushing to pull all the currently available data together in time for a science conference and public briefing in mid-October.

“We have set ourselves a target to gather everything we know about the south pole impact feature and expect to have a press release from what ever we conclude at the GSA (Geological Society of America) meeting on October 12. “We will tell the public what the options are.”

“We do not have a good analog to Vesta anywhere else in the Solar System and we’ll be studying it very intently.”

Impressive South Pole MountainTop at Rheasilvia Crater on Vesta
This mountain, which measures about 125 miles (200 kilometers) in diameter at its base, is one of the highest elevations on all known bodies with solid surfaces in the solar system. The image has been recorded with the framing camera aboard NASA's Dawn spacecraft from a distance of about 1,700 miles (2,700 kilometers). The image resolution is about 260 meters per pixel. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Right now Dawn is using its ion propulsion system to spiral down four times closer to Vesta, as it descends from the initlal survey orbit(about 2700 km, 1700 mi) to the new science orbit, elegantly named HAMO – or High Altitude Mapping Orbit (about 685 km.)

“Our current plan is to begin HAMO on Sept. 29, but we will not finalize that plan until next week,” Dr. Marc Rayman told Universe Today. Rayman, of NASA’s JPL, is Dawn’s Chief Engineer.

“Dawn’s mean altitude today (Sept. 20) is around 680 km (420 miles),” said Rayman .

“Dawn successfully completed the majority of the planned ion thrusting needed to reach its new science orbit and navigators are now measuring its orbital parameters precisely so they can design a final maneuver to ensure the spacecraft is in just the orbit needed to begin its intensive mapping observations next week.”

Watch for lots more stories upcoming on Vesta and the Dawn mission

Read Ken’s continuing features about Dawn
Space Spectacular — Rotation Movies of Vesta
3 D Alien Snowman Graces Vesta
NASA Unveils Thrilling First Full Frame Images of Vesta from Dawn
Dawn Spirals Down Closer to Vesta’s South Pole Impact Basin
First Ever Vesta Vistas from Orbit – in 2D and 3D
Dawn Exceeds Wildest Expectations as First Ever Spacecraft to Orbit a Protoplanet – Vesta
Dawn Closing in on Asteroid Vesta as Views Exceed Hubble
Dawn Begins Approach to Asteroid Vesta and Snaps First Images
Revolutionary Dawn Closing in on Asteroid Vesta with Opened Eyes

Posted on by Ken Kremer

Space Spectacular — Rotation Movies of Vesta

Viewing the South Pole of Vesta. This image obtained by Dawns framing camera and shows the south pole of the giant asteroid Vesta. Scientists are discussing whether the circular structure that covers most of this image originated by a collision with another asteroid, or by internal processes early in the asteroid's history. Images in higher resolution from Dawn's lowered orbit might help answer that question. The image was recorded from a distance of about 1,700 miles (2,700 kilometers). The image resolution is about 260 meters per pixel. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Take us into orbit Mr. Sulu!

The Dawn science team has released two spectacular rotation movies of the entire globe of the giant asteroid Vesta. The flyover videos give the distinct impression that you are standing on the bridge of the Starship Enterprise and gazing at the view screen as the ship enters orbit about a new planet for the first time and are about to begin an exciting new journey of exploration and discovery of the body you’re looking at below.

Thanks to NASA, DLR, ASI and Dawn’s international science and engineering team, we can all join the away team on the expedition to unveil Vesta’s alluring secrets.

Click the start button and watch protoplanet Vesta’s striking surface moving beneath from the perspective of Dawn flying above – in the initial survey orbit at an altitude of 2700 kilometers (1700 miles). Vesta is the second most massive object in the main asteroid belt and Dawn’s first scientific conquest.

Another video below was compiled from images taken earlier on July 24, 2011 from a higher altitude after Dawn first achieved orbit about Vesta and revealed that the northern and southern hemispheres are totally different.

The array of images in the videos was snapped by Dawn’s framing camera which was provided by the German Aerospace Center (DLR). The team then created a shape model from the images, according to Dr. Carol Raymond, Dawn’s Deputy Principal Investigator from NASA’s Jet Propulsion Laboratory in Pasadena, Calif.

The shape model will aid in studying Vesta’s strikingly diverse features of mountains, ridges, valley’s, scarps, cliffs, grooves, craters, even a ‘snowman’ and much more.

Notice that not all of Vesta is illuminated – because it’s northern winter at the asteroid. Vesta has seasons like Earth and the northern polar region in now in perpetual darkness. Data is collected over the day side and radioed back to Earth over the night side.

“On Vesta right now, the southern hemisphere is facing the sun, so everywhere between about 52 degrees north latitude and the north pole is in a long night,” says Dr. Rayman, Dawn’s Chief Engineer from JPL. “That ten percent of the surface is presently impossible to see. Because Dawn will stay in orbit around Vesta as together they travel around the sun, in 2012 it will be able to see some of this hidden scenery as the seasons advance.”

Another movie highlight is a thorough look at the gigantic south pole impact basin. The circular feature is several hundred miles wide and may have been created by a cosmic collision eons ago that excavated massive quantities of material and basically left Vesta lacking a south pole.

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The massive feature was discovered in images taken by the Hubble Space Telescope several years ago and mission scientists have been eager to study it up close in a way that’s only possible from orbit. Dawn’s three science instruments will investigate the south pole depression in detail by collecting high resolution images and spectra which may reveal the interior composition of Vesta.

Dawn entered the survey orbit on Aug. 11 and completed seven revolutions of 69 hours each on Sept. 1. It transmitted more than 2,800 pictures from the DLR framing camera covering the entire illuminated surface and also collected over three million visible and infrared spectra from the VIR spectrometer – provided by ASI, the Italian Space Agency. This results exceeded the mission objectives.

The Dawn spacecraft is now spiraling down closer using its ion propulsion system to the next mapping orbit – known as HAMO – four times closer than the survey orbit and only some 680 km (420 miles) above the surface.

Read Ken’s continuing features about Dawn
3 D Alien Snowman Graces Vesta
NASA Unveils Thrilling First Full Frame Images of Vesta from Dawn
Dawn Spirals Down Closer to Vesta’s South Pole Impact Basin
First Ever Vesta Vistas from Orbit – in 2D and 3D
Dawn Exceeds Wildest Expectations as First Ever Spacecraft to Orbit a Protoplanet – Vesta
Dawn Closing in on Asteroid Vesta as Views Exceed Hubble
Dawn Begins Approach to Asteroid Vesta and Snaps First Images
Revolutionary Dawn Closing in on Asteroid Vesta with Opened Eyes

Posted on by Ken Kremer

3 D Alien Snowman Graces Vesta

3D Snowman craters and Vesta’s Equatorial Region from Dawn. This anaglyph image of Vesta's equator with the crater feature named “snowman” (center, right) was put together from two clear filter images, taken on July 24, 2011 by the framing camera instrument aboard NASA's Dawn spacecraft. The anaglyph image shows hills, troughs, ridges and steep craters. The framing camera has a resolution of about 524 yards (480 meters) per pixel. Use red-green (or red-blue) glasses to view in 3-D (left eye: red; right eye: green [or blue]). Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

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An alien ‘Snowman’ on an alien World.

The ‘Snowman’ is a string of three craters and is among the most strange and prominent features discovered on a newly unveiled world in our solar system – the giant asteroid Vesta. It reminded team members of the jolly wintertime figure – hence its name – and is a major stand out in the 3 D image above and more snapshots below.

Until a few weeks ago, we had no idea the ‘Snowman’ even existed or what the rest of Vesta’s surface actually looked like. That is until NASA’s Dawn spacecraft approached close enough and entered orbit around Vesta on July 16 and photographed the Snowman – and other fascinating Vestan landforms.

“Each observation of Vesta is producing incredible views more exciting than the last”, says Dawn’s Chief Engineer, Dr. Marc Rayman of the Jet Propulsion Laboratory. “Every image revealed new and exotic landscapes. Vesta is unlike any other place humankind’s robotic ambassadors have visited.”

‘Snowman’ craters on Vesta. What is the origin of the ‘Snowman’?
The science team is working to determine how the ‘Snowman’ formed. This set of three craters is nicknamed ‘Snowman” and is located in the northern hemisphere of Vesta. NASA’s Dawn spacecraft obtained this image with its framing camera on August 6, 2011. This image was taken through the framing camera’s clear filter aboard the spacecraft. The framing camera has a resolution of about 280 yards (260 meters). Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

The Snowman is located in the pockmarked northern hemisphere of Vesta – see the full frame image below. The largest of the three craters is some 70 km in diameter. Altogether the trio spans roughly 120 km in length. See Image at Left

“Craters, Craters, Craters Everywhere” – that’s one thing we can now say for sure about Vesta.

And soon we’ll known a lot more about the mineralogical composition of the craters and Vesta because spectral data is now pouring in from Dawn’s spectrometers.

After being captured by Vesta, the probe “used its ion propulsion system to spiral around Vesta, gradually descending to its present altitude of 2700 kilometers (1700 miles),” says Chief Engineer Rayman. “As of Aug.11, Dawn is in its survey orbit around Vesta.”

Dawn has now begun its official science campaign. Each orbit currently last 3 days.

Dawn’s scientific Principal Investigator, Prof. Chris Russell of UCLA, fondly calls Vesta the smallest terrestrial Planet !

I asked Russell for some insight into the Snowman and how it might have formed. He outlined a few possibilities in an exclusive interview with Universe Today.

“Since there are craters, craters, craters everywhere on Vesta it is always possible that these craters struck Vesta in a nearly straight line but many years apart,” Russell replied.

“On the other hand when we see ‘coincidences’ like this, we are suspicious that it is really not a coincidence at all but that an asteroid that was a gravitational agglomerate [sometimes called a rubble pile] struck Vesta.”

“As the loosely glued together material entered Vesta’s gravity field it broke apart with the parts moving on slightly different paths. Three big pieces landed close together and made adjacent craters.”

So, which scenario is it ?

“Our science team is trying to figure this out,” Russell told me.

“They are examining the rims of the three craters to see if the rims are equally degraded, suggesting they are of similar age. They will try to see if the ejecta blankets interacted or fell separately”

“The survey data are great but maybe we will have to wait until the high altitude mapping orbit [HAMO] to get higher resolution data on the rim degradation.”

Dawn will descend to the HAMO mapping orbit in September.

Close-up View of 'Snowman' craters.
This image of the set of three craters informally nicknamed ‘Snowman’ was taken by Dawn’s framing camera on July 24, 2011 after the probe entered Vesta’s orbit. Snowman is located in the northern hemisphere of Vesta. The image was taken from a distance of about of about 3,200 miles (5,200 kilometers). The framing camera was provided by Germany. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Russell and the Dawn team are elated with the fabulous results so far, some of which have been a total surprise.

How old is the Snowman ?

“We date the age of the surface by counting the number of craters on it as a function of size and compare with a model that predicts the number of craters as a function of size and as a function of time from the present,” Russell responded.

“However this does not tell us the age of a crater. If the crater destroyed all small craters in its bowland and left a smooth layer [melt] then the small crater counts would be reset at the impact.”

“Then you could deduce the age from the crater counts. You can also check the degradation of the rim but that is not as quantitative as the small crater counts in the larger crater. The team is doing these checks but they may have to defer the final answer until they obtain the much higher resolution HAMO data,” said Russell.

Besides images, the Dawn team is also collecting spectral data as Dawn flies overhead.

“The team is mapping the surface with VIR- the Visible and Infrared Mapping Spectrometer – and will have mineral data shortly !”, Russell told me.

At the moment there is a wealth of new science data arriving from space and new missions from NASA’s Planetary Science Division are liftoff soon. Juno just launched to Jupiter, GRAIL is heading to the launch pad and lunar orbit and the Curiosity Mars Science Laboratory (MSL) is undergoing final preflight testing for blastoff to the Red Planet.

Russell had these words of encouragement to say to his fellow space explorers;

“Dawn wishes GRAIL and MSL successful launches and hopes its sister missions join her in the exploration of our solar system very shortly.”

“This year has been and continues to be a great one for Planetary Science,” Russell concluded.

Detailed 'Snowman' Crater
Dawn obtained this image with its framing camera on August 6, 2011. This image was taken through the camera’s clear filter. The camera has a resolution of about 260 meters per pixel. This image shows a detailed view of three craters, informally nicknamed 'Snowman' by the camera’s team members. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Dawn snaps First Full-Frame Image of Asteroid Vesta – Snowman at Left
NASA's Dawn spacecraft obtained this image of the giant asteroid Vesta with its framing camera on July 24, 2011. It was taken from a distance of about 3,200 miles (5,200 kilometers). Dawn entered orbit around Vesta on July 15, and will spend a year orbiting the body. The Dawn mission to Vesta and Ceres is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif. The framing cameras were built by the Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany, and the German Aerospace Center (DLR) Institute of Planetary Research, Berlin. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Read my prior features about Dawn
NASA Unveils Thrilling First Full Frame Images of Vesta from Dawn
Dawn Spirals Down Closer to Vesta’s South Pole Impact Basin
First Ever Vesta Vistas from Orbit – in 2D and 3D
Dawn Exceeds Wildest Expectations as First Ever Spacecraft to Orbit a Protoplanet – Vesta
Dawn Closing in on Asteroid Vesta as Views Exceed Hubble
Dawn Begins Approach to Asteroid Vesta and Snaps First Images
Revolutionary Dawn Closing in on Asteroid Vesta with Opened Eyes

Posted on by Ray Sanders

Have a Vesta Fiesta This Weekend!

To help celebrate the start of the Dawn mission to Vesta, NASA is organizing a “Vesta Fiesta!” After traveling the solar system for nearly four years, the Dawn spacecraft is now entering the “science” phase of its mission. Given the fact that Dawn is the first spacecraft to orbit an object in the asteroid belt, a fiesta is in order! (Here in Arizona we relish ANY excuse to fiesta!) Between August 5 and August 7, 2011, Vesta Fiestas will be held to help celebrate Dawn’s arrival at Vesta.

NASA is encouraging fans of the Dawn mission to join the celebration by hosting events at local clubs, schools, museums or societies. NASA has also provided numerous resources that are free to use for Vesta Fiestas, including games and activities, media resources (invitations, audio files, observing info, etc.) and live video on August 6th from the “Flagship” celebration at JPL in Pasedena, California.

If you’d like to participate by hosting your own party, or to find a party in your area, visit this page on the Dawn website, or on Facebook at: http://www.facebook.com/event.php?eid=225252850843508

You can also follow the Dawn mission on Twitter

After studying the asteroid Vesta, Dawn will continue on to study dwarf planet Ceres, also in the main asteroid belt between Mars and Jupiter.

To help encourage participation, I humbly offer my Spicy Fiesta Cheese Dip:

Ingredients:
1lb sausage (breakfast or Italian)
1 block of Velveeta (cut into ~1 inch square cubes)
1 jar of your favorite salsa and (Optional) 1 small can (4oz?) of diced green chile peppers – Not Red Hot Chili Peppers! Flea, Chad and Anthony hate being diced.)

Procedure: Place 1/2 of the cubed Velveeta in a crock pot, set to “high”. Cook sausage and diced peppers completely in a skillet, add cooked sausage and peppers to the crock pot along with the salsa and remaining velveeta. Leave crock pot on “high” until all the Velveeta is melted, then set to “low” – stir often! Serve with tortilla chips and an ice cold drink of your choice.

If you’d like to learn more about the Dawn mission to Vesta and Ceres, you can visit the Dawn website.

Posted on by Ken Kremer

NASA Unveils Thrilling First Full Frame Images of Vesta from Dawn

Dawn snaps First Full-Frame Image of Asteroid Vesta. NASA's Dawn spacecraft obtained this image of the giant asteroid Vesta with its framing camera on July 24, 2011. It was taken from a distance of about 3,200 miles (5,200 kilometers). Dawn entered orbit around Vesta on July 15, and will spend a year orbiting the body. After that, the next stop on its itinerary will be an encounter with the dwarf planet Ceres. The Dawn mission to Vesta and Ceres is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif. The framing cameras have been developed and built under the leadership of the Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany, with significant contributions by the German Aerospace Center (DLR) Institute of Planetary Research, Berlin, and in coordination with the Institute of Computer and Communication Network Engineering, Braunschweig, Germany. The framing camera project is funded by NASA, the Max Planck Society and DLR. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

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NASA has just released the first full frame images of Vesta– and they are thrilling! The new images unveil Vesta as a real world with extraordinarily varied surface details and in crispy clear high resolution for the first time in human history.

Vesta appears totally alien and completely unique. “It is one of the last major uncharted worlds in our solar system,” says Dr. Marc Rayman, Dawn’s chief engineer and mission manager at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “Now that we are in orbit we can see that it’s a unique and fascinating place.”

“We have been calling Vesta the smallest terrestrial planet,” said Chris Russell, Dawn’s principal investigator at the UCLA. “The latest imagery provides much justification for our expectations. They show that a variety of processes were once at work on the surface of Vesta and provide extensive evidence for Vesta’s planetary aspirations.”

Dawn launch on September 27, 2007 by a Delta II Heavy rocket from Cape Canaveral Air Force Station, Florida. Credit: Ken Kremer

The newly published image (shown above) was taken at a distance of 3,200 miles (5,200 kilometers) by Dawn’s framing camera as the probe continues spiraling down to her initial science survey orbit of some 1,700 miles (2,700 km) altitude. The new images show the entire globe all the way since the giant asteroid turns on its axis once every five hours and 20 minutes.

Vesta and its new moon – Dawn – are approximately 114 million miles (184 million kilometers) distant away from Earth.

“The new observations of Vesta are an inspirational reminder of the wonders unveiled through ongoing exploration of our solar system,” said Jim Green, planetary division director at NASA Headquarters in Washington.

The Dark Side of Vesta Captured by Dawn
NASA's Dawn spacecraft obtained this image over the northern hemisphere with its framing camera on July 23, 2011. It was taken from a distance of about 3,200 miles (5,200 kilometers) away from the giant asteroid Vesta. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Dawn was launched atop a Delta II Heavy booster rocket in September 2007, took a gravity assist as it flew past Mars and has been thrusting with exotic ion propulsion for about 70 percent of the time ever since.

Dawn will spend 1 year collecting science data in orbit around Vesta before heading off to the Dwarf Planet Ceres.

The science team has just completed their press briefing. Watch for my more detailed report upcoming soon.

And don’t forget JUNO launches on Aug 5 – It’s an exciting week for NASA Space Science and I’ll be reporting on the Jupiter orbiter’s blastoff and more – as Opportunity closes in on Spirit Point !

NASA’s groundbreaking interplanetary science is all inter connected – because Vesta and Ceres failed to form into full-fledged planets thanks to the disruptive influence of Jupiter.

Read my prior features about Dawn
Dawn Spirals Down Closer to Vesta’s South Pole Impact Basin
First Ever Vesta Vistas from Orbit – in 2D and 3D
Dawn Exceeds Wildest Expectations as First Ever Spacecraft to Orbit a Protoplanet – Vesta
Dawn Closing in on Asteroid Vesta as Views Exceed Hubble
Dawn Begins Approach to Asteroid Vesta and Snaps First Images
Revolutionary Dawn Closing in on Asteroid Vesta with Opened Eyes

Posted on by Ken Kremer

Dawn Spirals Down Closer to Vesta’s South Pole Impact Basin

South Polar Region of Vesta - Enhanced View. NASA's Dawn spacecraft obtained this image centered on the south pole of Vesta with its framing camera on July 18, 2011. The image has been enhanced to bring out more surface details. It was taken from a distance of about 6,500 miles (10,500 kilometers) away from the protoplanet Vesta. The smallest detail visible is about 1.2 miles (2.0 km). Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA. Enhanced and annotated by Ken Kremer

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NASA’s Dawn Asteroid Orbiter is now spiraling down ever closer to the protoplanet Vesta – since arriving on July 16 – and capturing magnificent new high resolution images of the huge impact basin at the South Pole that dominates the surface. See enhanced image here.

The Dawn team just released a new image taken by the framing camera on July 18 as the orbiter flew from the day side to the night side at an altitude of 10,500 kilometers above Vesta, the second most massive body in the main Asteroid Belt between Mars and Jupiter.

NASA's Dawn spacecraft obtained this image centered on the south pole with its framing camera on July 18, 2011. It was taken from a distance of about 6,500 miles (10,500 kilometers) away from the protoplanet Vesta. The smallest detail visible is about 1.2 miles (2.0 km). Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

“I find this picture very dramatic !” exclaimed Dr. Marc Rayman, Dawn Chief Engineer from the NASA’s Jet Propulsion Laboratory in Pasadena, Calif., in an interview with Universe Today.

“Dawn acquired this image after it had flown past the terminator and its orbit began taking it over the night side of Vesta.”

“After having this view, the spacecraft resumed gradually spiraling around its new home, heading for survey orbit where it will begin intensive observations of Vesta,” Rayman told me.

Dawn will reach the initial science survey orbit in early August, approximately 1700 miles above the battered surface. Vesta turns on its axis once very five hours and 20 minutes.

Vesta suffered an enormous cosmic collision eons ago that apparently created a gigantic impact basin in the southern hemisphere and blasted enormous quantities of soil, rocks and dust into space. Some 5% of all meteorites found on Earth originate from Vesta.

“The south pole region was declared to be a large impact basin after the Hubble Space Telescope (HST) data and images were obtained,” elaborated Prof. Chris Russell, Dawn Principal Investigator from UCLA.

“Now that we have higher resolution images we see that this region is unlike any other large impact on a small body but much of our experience here is on icy bodies of similar size,” Russell told me.

Dawn’s new images of Vesta taken at close range from just a few thousand miles away, now vastly exceed those taken by Hubble as it circled in Earth orbit hundreds of millions of miles away and may cause the science team to reevaluate some long held theories.

“The team is looking forward to obtaining higher resolution data over this region to look for confirmatory evidence for the impact hypothesis. They are not yet willing to vote for or against the HST interpretation. Needless to say the team got very excited by this image,” said Russell.

Dawn will orbit Vesta for one year before heading to its final destination, the Dwarf Planet Ceres.

Simulated View of Vesta from Dawn on July 23, 2011. Credit: NASA

Read my prior features about Dawn
First Ever Vesta Vistas from Orbit – in 2D and 3D
Dawn Exceeds Wildest Expectations as First Ever Spacecraft to Orbit a Protoplanet – Vesta
Dawn Closing in on Asteroid Vesta as Views Exceed Hubble
Dawn Begins Approach to Asteroid Vesta and Snaps First Images
Revolutionary Dawn Closing in on Asteroid Vesta with Opened Eyes