NASA Spacecraft to Enter Asteroid’s Orbit on July 15

All Eyes on Vesta: NASA's Dawn spacecraft obtained this image of the giant asteroid Vesta with its framing camera on July 9, 2011. It was taken from a distance of about 26,000 miles (41,000 kilometers) away from Vesta, which is also considered a protoplanet because it is a large body that almost became a planet. Each pixel in the image corresponds to roughly 2.4 miles (3.8 kilometers).

On July 15, NASA’s Dawn spacecraft will begin a prolonged encounter with the asteroid Vesta, making the mission the first to enter orbit around a main-belt asteroid.
The main asteroid belt lies between the orbits of Mars and Jupiter. Dawn will study Vesta for one year, and observations will help scientists understand the earliest chapter of our solar system’s history.
As the spacecraft approaches Vesta, surface details are coming into focus, as seen in a recent image taken from a distance of about 26,000 miles (41,000 kilometers). The image is available at: http://www.nasa.gov/mission_pages/dawn/multimedia/dawn-image-070911.html .
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 them. At that point, the spacecraft and asteroid 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. 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.
Dawn’s mission to Vesta and Ceres is managed by JPL for NASA’s Science Mission Directorate in Washington. Dawn is a project of the directorate’s Discovery Program, which is managed by NASA’s Marshall Space Flight Center in Huntsville, Ala. UCLA is responsible for overall Dawn mission science. Orbital Sciences Corp. of Dulles, Va., designed and built the spacecraft. The German Aerospace Center, the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute are part of the mission team.
For a current image of Vesta and more information about the Dawn mission, visit: http://www.nasa.gov/dawn and http://dawn.jpl.nasa.gov .You also can follow the mission on Twitter at: http://www.twitter.com/nasa_dawn.
http://www.nasa.gov/mission_pages/dawn/news/dawn20110714.html

Join NASA in Measuring an Asteroid

In a dramatic example of occultation, a Saturn moon, Rhea, emerges after being occulted by the larger moon Titan.

On the evening of July 3 at 11:05:30 p.m. EDT — at a distance of 280 millon miles into space that poses no threat to Earth — 52 Europa will pass in front of star TYC 0292-00339-1 in the constellation Virgo. The asteroid will eclipse the star’s light for 17.9 seconds in a process known as occultation. Here on Earth, astronomers can measure the exact length of time the star’s light is blocked and use those calculations to help verify the size of 52 Europa. They’ll also have alive Web chat to discuss how to measure the asteroid 52 Europa on the evening of July 3, 2011, from 9 p.m. to midnight EDT. You can view a map of the occultation’s path across North America.
Ahead of the live Web chat on July 3, you may already have some questions about occulations, eclipses, transits, and 52 Europe. Below is some information that you may find useful ahead of the event.
What is asteroid 52 Europa?
By volume, asteroid 52 Europa is ….. Continue reading Join NASA in Measuring an Asteroid

Video: Asteroid 2011 MD – Earth Flyby

Asteroid 2011 MD imaged by Peter Birtwhistle (Galaxy Picture Library)- www.skymania.com

A newly discovered (on 22nd June 2011) asteroid called “ASTEROID 2011 MD” will pass by earth at a distance of 17700 km on 27th June,2011 at 13.56 UTC (6.56 IST).Size of asteroid is expected to be 9 to 45 meters.There is no danger to earth. Bcos asteroid of this size would burn up if it tries to enter in earth atmosphere.Info here is correct as on 24 June 2011 4 a.m.

Vesta’s Surface Comes into View

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This movie shows surface details beginning to resolve as NASA’s Dawn spacecraft closes in on the giant asteroid Vesta. The framing camera aboard NASA’s Dawn spacecraft obtained the images used for this animation on June 1, 2011, from a distance of about 300,000 miles (483,000 kilometers).

Vesta’s jagged shape, sculpted by eons of cosmic impacts in the main asteroid belt, is apparent. Variations in surface brightness and hints of surface features can be seen. Vesta’s south pole is to the lower right at about the 5 o’clock position.

Vesta is 330 miles (530 kilometers) in diameter and the second most massive object in the asteroid belt. It is also the only large asteroid with a basaltic surface formed due to volcanic processes early in the solar system’s history. Vesta is considered a protoplanet because it is a large body that almost formed into a planet.

The video presents 20 frames, looped five times, that span a 30-minute period. During that time, Vesta rotates about 30 degrees. The images included here are used by navigators to fine-tune Dawn’s trajectory during its approach to Vesta, with arrival expected on July 16, 2011.

The Dawn mission to Vesta and Ceres is managed by the Jet Propulsion Laboratory, for NASA’s Science Mission Directorate, Washington, D.C. It is a project of the Discovery Program managed by NASA’s Marshall Space Flight Center, Huntsville, Ala. UCLA, is responsible for overall Dawn mission science. Orbital Sciences Corporation of Dulles, Va., designed and built the Dawn spacecraft.

http://www.nasa.gov/mission_pages/dawn/multimedia/pia14121.html

How Jupiter robbed Mars of mass and built the asteroid belt as the planets formed our solar system billions of years ago

Scientists have long puzzled over why Mars is only about half the size and one-tenth the mass of Earth.
As next-door neighbors in the solar system formed about the same time, they might be expected to be more similar – by rights, Mars should be as big as Earth and Venus
But a paper published this week provides an explanation and also reveals why the asteroid belt is such a strange assortment of rocks and ice.

Family portrait: Composite image of Venus, Earth and Mars shows how small the fourth planet from the Sun is in comparison with its larger siblings

While the solar system was forming, a process which began approximately 4.6 billion years ago, the gas giant Jupiter went wandering in towards the Sun, on the way dragging comets from beyond the asteroid belt as Jupiter moved inwards towards Mars.
It then moved out again to gravitate towards another gas giant, Saturn, as it formed, this time dragging dry rocks from inside the belt as it moved back outwards again.
All this material would otherwise have coalesced with Mars, giving it water in abundance and the mass to retain it with its gravitational pull.
Instead it ended up as the small, dry and probably dead planet we see today.

Dead planet: This picture taken by the Mars Exploration Rover Spirit shows the dry desolate plains that have covered the surface for eons

Dr. Kevin Walsh, a research scientist at Southwest Research Institute, in San Antonio, Texas, led an international team performing computer simulations of the early solar system.
They showed how an infant Jupiter may have migrated to within 1.5 astronomical units (AU, the distance from the Sun to the Earth) of the Sun, stripping a lot of material from the region and essentially starving Mars of formation materials.
‘If Jupiter had moved inwards from its birthplace down to 1.5 AU from the Sun, and then turned around when Saturn formed as other models suggest, eventually migrating outwards towards its current location, it would have truncated the distribution of solids in the inner solar system at about 1 AU and explained the small mass of Mars,’ said Dr Walsh.

Big bully: Composite image of Jupiter, left, and Saturn with its rings, planets which now orbit the sun far beyond the asteroid belt

‘The problem was whether the inward and outward migration of Jupiter through the 2 to 4 AU region could be compatible with the existence of the asteroid belt today, in this same region. So, we started to do a huge number of simulations.
‘The result was fantastic.
‘Our simulations not only showed that the migration of Jupiter was consistent with the existence of the asteroid belt, but also explained properties of the belt never understood before.’

Building blocks: Asteroid Lutetia and Comet Ikeya-Zhang show us what kind of material was around in the early solar system to be worked into planets by gravity

The asteroid belt is populated with two very different types of rubble, very dry bodies as well as water-rich orbs similar to comets.
Water is too volatile to have been present at Earth’s formation and must have been subsequently delivered from outer, colder parts of the Solar System .The water was probably delivered by planetoids and comets thrown out of the asteroid belt by Jupiter.
Walsh and collaborators showed that the passage of Jupiter depleted and then re-populated the asteroid belt region with inner-belt bodies originating between 1 and 3 AU as well as outer-belt bodies originating between and beyond the giant planets, producing the significant compositional differences existing today across the belt.

Red Planet: Mars, captured in the immensity of space by the Hubble telescope

The collaborators call their simulation the Grand Tack Scenario, from the abrupt change in the motion of Jupiter at 1.5 AU, like that of a sailboat tacking around a buoy.
The migration of the gas giants is also supported by observations of many extra-solar planets found in widely varying ranges from their parent stars, implying migrations of planets elsewhere in universe.
The paper, A Low Mass for Mars from Jupiter’s Early Gas-Driven Migration, appeared in the June 5 issue of the journal Nature, written by Dr Walsh, Alessandro Morbidelli of the Université de Nice, France, Sean N. Raymond of Université de Bordeaux, France; David P.O’Brien of Planetary Science Institute in Tucson, Ariz.; and Avi M. Mandell of NASA’s Goddard Space Flight Center.
The research was funded by the Helmholtz Alliance, the French National Center for Scientific Research and NASA
http://www.dailymail.co.uk/sciencetech/article-1394950/How-Jupiter-robbed-Mars-mass-built-asteroid-belt-planets-formed-solar-billions-years-ago.html#ixzz1OZplAkMK

Read also: Jupiter’s Youthful Travels Redefined Solar System

Cosmic collision

Nasa monitors unusually bright asteroid after 11,000mph impact 

Collision: Faint dust plumes bookend asteroid Scheila in this composite taken by Nasa’s Swift satellite on December 15 last year when it was 232million miles from Earth

An unexpectedly bright asteroid that sported short-lived plumes had collided with a smaller body, scientists have said.

The aftermath of the impact on Scheila was first spotted by the University of Arrizona’s Catalina Sky Survey on December 11 last year.
It revealed Scheila to be twice as bright as expected and immersed in a faint comet-like glow….
Read more: http://www.dailymail.co.uk/sciencetech/article-1381932/Nasa-monitors-unusually-bright-asteroid-Scheila-weeks-11-000mph-impact.html#ixzz1L1RXB1Dg