Dawn Reveals New Secrets About Giant Asteroid Vesta

Composite images from the framing camera aboard NASA’s Dawn spacecraft show three views of a terrain with ridges and grooves near Aquilia crater in the southern hemisphere of the giant asteroid Vesta. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Composite images from the framing camera aboard NASA’s Dawn spacecraft show three views of a terrain with ridges and grooves near Aquilia crater in the southern hemisphere of the giant asteroid Vesta. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

NASA’s Dawn spacecraft, which has been exploring the 330-mile wide asteroid Vesta since 2011, is continuing to reveal new details about the giant space rock and its geology.  The findings, presented today at the European Geosciences Union meeting in Vienna, Austria, will help researchers better understand the processes that led to the formation of our solar system.

Images taken from varying distances above Vesta’s surface reveal new details about its composition, internal structure, and dramatic temperature changes taking place on the asteroid’s surface.  Much of the materials seen by Dawn are rich in iron and magnesium minerals, which are found on Earth in volcanic rock.  Researchers also see breccias, which are rocks fused during impacts from space debris.  Images also reveal what is described as “smooth pond-like deposits”, which scientists believe may be the result of fine dust settling in low lying regions after impact events.

Images from NASA's Dawn mission shows topography of the southern hemisphere of the giant asteroid Vesta and a map of Vesta’s gravity variations that have been adjusted to account for Vesta’s shape. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Images from NASA's Dawn mission shows topography of the southern hemisphere of the giant asteroid Vesta and a map of Vesta’s gravity variations that have been adjusted to account for Vesta’s shape. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

“Dawn now enables us to study the variety of rock mixtures making up Vesta’s surface in great detail,” said Harald Hiesinger, a Dawn participating scientist at Münster University in Germany.  “The images suggest an amazing variety of processes that paint Vesta’s surface.”

At the asteroid’s south pole, in an area known as the Tarpeia crater, researchers have identified bands of minerals that appear as layers on the crater’s steep slopes.  Layers at the surface reveal signs of contamination from impact events, while layers under Vesta’s surface preserve more of the giant asteroid’s original characteristics.  Possible landslides on the Tarpeia crater’s slopes also reveal other hidden mineral patterns, which is strong evidence to show that Vesta’s surface is constantly changing and renewing.

In these images of Tarpeia crater,  the brown and yellow materials have similar composition, but the brown material receives less illumination from sunlight and appears darker. The material on the edge of the crater rim that appears blue in these images suggests a different, fresher material. This material must have been exposed during a landslide or a similar recent event that occurred on the side of the crater. Researchers think the blue areas have been less altered over time, preserving more of the original material of Vesta.  Image Credit: NASA/JPL-Caltech/UCLA/INAF
In these images of Tarpeia crater, the brown and yellow materials have similar composition, but the brown material receives less illumination from sunlight and appears darker. The material on the edge of the crater rim that appears blue in these images suggests a different, fresher material. This material must have been exposed during a landslide or a similar recent event that occurred on the side of the crater. Researchers think the blue areas have been less altered over time, preserving more of the original material of Vesta. Image Credit: NASA/JPL-Caltech/UCLA/INAF

Dawn has also mapped Vesta’s surface temperatures in the highest resolution of any asteroid to date, and data reveals temperatures varying from as warm as -10 degrees Fahrenheit in the sunniest spots to -150 degrees Fahrenheit in the shadows.  It’s very likely that it gets even colder, because Dawn cannot measure temperatures on the surface lower than -150 degrees Fahrenheit.

“After more than nine months at Vesta, Dawn’s suite of instruments has enabled us to peel back the layers of mystery that have surrounded this giant asteroid since humankind first saw it as just a bright spot in the night sky,” said Carol Raymond, Dawn deputy principal investigator at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif.  “We are closing in on the giant asteroid’s secrets.”

For more information about NASA’s Dawn mission exploring the asteroid Vesta, please visit www.nasa.gov/dawn

 

 

One Comment

  1. Now that we’re hearing a lot about mineral resources and “Planetary Resources, Inc.”,Would they report the findings in minerals( by name)publicly or is this information reserved for scientists and considered classified? Wouldn’t this create a “rush” from other countries,that may be unqualified technically, creating a madness and risking our “blue marble” from the dangers of failed launches or a Star Wars in it’s beginnings?

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