LUTETIA - Huge Asteroid in A Thick Dust Blanket

 Outer Space is still virtually an unknown entity. Every day new worlds are being uncovered as the technology improves. New planets, moons and asteroids are being identified and named on a daily basis, for example, an asteroid named Lutetia. According to the following article, a trip to Lutetia may be very uncomfortable. Read on . . .
     . . . June


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Huge Asteroid Wrapped in Thick Dust Blanket
Yahoo! News:

If astronauts ever visit the asteroid Lutetia, they may have to strap on snowshoes to avoid sinking into its nearly half-mile-thick layer of dust.

Dusty debris shrouds the huge asteroid to a depth of at least 2,000 feet (600 meters), scientists have calculated. The dust probably resembles the regolith found on the moon, and it's a result of the intense cosmic pummeling Lutetia has endured from other space rocks since the birth of the solar system.

'It must have been produced by impacts,' said Rita Schulz of the European Space Agency in a media briefing yesterday (Oct. 4) in Pasadena, Calif. The announcement came at a conference organized by the American Astronomical Society's Division of Planetary Sciences.

The new look at Lutetia, which is located in the asteroid belt between Mars and Jupiter, is the result of a close fly-by made by ESA's Rosetta spacecraft in July. Rosetta, whose chief task is chasing down and studying a comet, zoomed to within 1,900 miles (3,162 km) of Lutetia, making it the largest asteroid ever to be visited by a space probe.

Rosetta snapped some detailed photos and probed the space rock from afar with a suite of instruments. The data confirmed that Lutetia is an elongated body with its longest side spanning approximately 81 miles (130 km), ESA officials have said.

But it took some time for scientists to process and analyze much of Rosetta's data. Over the last few months, they scrutinized some of Lutetia's many craters, measuring how deep they are. Researchers then compared that information with predictions of how deep such craters are expected to be based on theoretical models.

The craters were much shallower than researchers had anticipated, Schulz said, because of the thick layer of dusty debris. Indeed, one of Rosetta's most dramatic photos shows a landslide of dust at the bottom of an enormous crater.


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Hubble Space Telescope Helps NASA With Vesta Mission

Asteroid Vesta

We tend to forget that there is always ongoing exploration in outer space - if not manned, then by telescopes. The NASA mission described below is one such endeavor. The new Hubble's Wide Field Camera 3 just added in February is helping to correct some previously calculated orientations as new technology becomes available.
    . . . June


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NASA Mission to Asteroid Gets Help From Hubble Space
Telescope -- WASHINGTON, Oct. 8 /PRNewswire-USNewswire/

NASA's Hubble Space Telescope has captured images of the large asteroid Vesta that will help scientists refine plans for the Dawn spacecraft's rendezvous with Vesta in July 2011



Scientists have constructed a video from the images that will help improve pointing instructions for Dawn as it is placed in a polar orbit around Vesta. Analyses of Hubble images revealed a pole orientation, or tilt, of approximately four degrees more to the asteroid's east than scientists previously thought. The new


This means the change of seasons between the southern and northern hemispheres of Vesta may take place about a month later than previously expected while Dawn is orbiting the asteroid. The result is a change in the pattern of sunlight expected to illuminate the asteroid. Dawn needs solar illumination for imaging and some mapping activities.

'While Vesta is the brightest asteroid in the sky, its small size makes it difficult to image from Earth,' said Jian-Yang Li, a scientist participating in the Dawn mission from the University of Maryland in College Park. 'The new Hubble images give Dawn scientists a better sense of how Vesta is spinning because our new views are 90 degrees different from our previous images. It's like having a street-level view and adding a view from an airplane overhead.'

The recent images were obtained by Hubble's Wide Field Camera 3 in February. The images complemented previous ones of Vesta taken from ground-based telescopes and Hubble's Wide Field and Planetary Camera 2 between 1983 and 2007. Li and his colleagues looked at 216 new images -- and a total of 446 Hubble images overall -- to clarify how Vesta was spinning. The journal Icarus recently published the report online.

"The new results give us food for thought as we make our way toward Vesta," said Christopher Russell, Dawn's principal investigator at the University of California, Los Angeles. "Because our goal is to take pictures of the entire surface and measure the elevation of features over most of the surface to an accuracy of about 33 feet, or the height of a three-story building, we need to pay close attention to the solar illumination. It looks as if Vesta is going to have a late northern spring next year, or at least later than we planned."

Launched in September 2007, Dawn will leave Vesta to encounter the dwarf planet Ceres in 2015. Vesta and Ceres are the most massive objects in the main asteroid belt between Mars and Jupiter. Scientists study these celestial bodies as examples of the building blocks of terrestrial planets like Earth. Dawn is approximately 134 million miles away from Vesta. Next summer, the spacecraft will make its own measurements of Vesta's rotating surface and allow mission managers to pin down its axis of spin.

"Vesta was discovered just over 200 years ago, and we are excited now to be on the threshold of exploring it from orbit," said Bob Mase, Dawn's project manager at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif. "We planned this mission to accommodate our imprecise knowledge of Vesta. Ours is a journey of discovery and, with our ability to adapt, we are looking forward to collecting excellent science data at our target."

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