Asteroids Too Close to Home

Astronomers estimate that there are around 500,000 undiscovered objects that are near Earth. Each one is at least 30 meters across. One of those objects is the recently discovered asteroid 2012 DA14. This asteroid was recently discovered by citizen scientists on February 22, 2012 after it passed by our little planet. The asteroid measures 50 meters across and is on an orbit one day longer than Earth’s orbit. The asteroid’s orbit and Earth’s orbit crosses paths twice each year. Read More →

Dawn Spacecraft Returns Amazing Results from Astroid Vesta

Image credit: NASA/JPL-Caltech

Dawn Mission Discussion (Click to Listen to Audio)

NASA’s Dawn spacecraft is quickly approaching the end of its 10 week mission to study the asteroid Vesta.The spacecraft has been using a framed camera to return the closest photos of an asteroid ever seen. Vesta lies in the doughnut-like ring between Mars and Jupiter. Vesta is the second heaviest object in the asteroid belt. The images have shown many small craters some measuring 10 miles in diameter and up to 6 miles deep, small grooves and lineaments. Scientists hope that when the images have been further examined they will better understand the origins of the universe. Scientists have been most amazed at the discovery of a mountain three times taller than Mount Everest. Scientists have found that over half of the surface of Vesta is so cold and receives so little sunshine that ice could have survived there for billions of years (see image below).

Early examination of the information collected by Dawn including gravity mapping, gamma rays and neutron analysis along with the photos have led scientist to believe that the asteroid was formed by a large impact. Scientists feel that ice could be present beneath the surface at either pole. However, these poles see more sunlight than the equator. Temperatures at the pole are believed to hover near minus 200 degrees Fahrenheit. Scientists are using the mission to explore the role water played in early planet and asteroid formation.

Reference:
http://www.nasa.gov/mission_pages/dawn/news/dawn20120125.html
http://www.nasa.gov/mission_pages/dawn/multimedia/gallery-index.html
http://dawn.jpl.nasa.gov/

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

Milky Way’s Black Hole Devouring Asteroids?

At the center of the Milky Way galaxy (encompasses our solar system) there is a black hole that features a mass of more than three million times that of the sun at its center. This black hole, known as Sagittarius A (SGR A for short), has been detected through various sources of radiation that stem from the direction of the center of the galaxy. However, SGR A has now been found to be grazing and vaporizing asteroids that pass near it according to recent data released from NASA’s Chandra X-ray Observatory. This discovery comes with the finding that there is a cloud of trillions of asteroids and comets hovering around the black hole. Such a finding redefines the current environmental criteria for an asteroid or comet to form in space.

SGR A has likely been consuming tremendous numbers of asteroids as of late as the black hole has been emanating x-ray radiation in larger quantities than usual. Black holes hold true to the notion that ‘what goes in must come out,’ so they often spit out high amounts of radiation as they consume stellar objects. The asteroids and comets from the nearby cloud that pass within approximately 100 million miles of SGR A are likely hopelessly shredded. The space rocks are destroyed due to the high tidal forces associated with the black hole’s mass which creates enormous friction. The asteroids and comets are ripped apart in a similar fashion by which Saturn forms its rings with the exception that these rocks burn up like a meteor. This discovery is just one more clue to the overall mystery of the Milky Way galaxy.

Image credit: universetoday.com