Asteroid Will Pass Closer To Earth Than Many Satellites

Press Release
March 15, 2012

Mat Kaplan
Voice: 626-793-5100

In less than a year, an asteroid that is half the size of a football field will pass within just a few thousand miles of our planet. The discovery of this object, dubbed 2012 DA14, was made possible by a Shoemaker Near Earth Object (NEO) grant provided by the Planetary Society.

The giant space rock was discovered on February 22, 2012 by La Sagra Observatory in southern Spain. One of the observatory’s telescopes had recently been upgraded through the Planetary Society grant. Its new camera enabled detection of fast moving objects like 2012 DA14 – requiring very fast imaging for discovery and determination of their paths. The upgraded instrument has far outperformed the Observatory’s other telescopes. It has found more than ten NEOs, along with a previously unknown comet.

At fifty meters across, 2012 DA14 is similar in size to the object that caused the Tunguska air burst over Siberia in 1908, leveling 2,000 square kilometers of forest. Fortunately, there is no danger of impact during the next pass of 2012 DA14.

“This asteroid is a wakeup call for the importance of defending the Earth from future asteroid impacts,” says Bill Nye, Chief Executive Officer of The Planetary Society. “Big impacts don’t happen often, but they will happen.”

2012 DA14 will come closest to Earth on February 15, 2013. It will zoom to within about 3.5 Earth radii or about 22,500 km from the Earth’s surface, well within the orbit of geostationary communications satellites (35,800 km). Current estimates are that it will be about magnitude 7 in brightness – not quite visible to the naked eye, but within reach of binoculars or a small telescope. It will fly across the sky at about one Moon diameter per minute.

Additional follow-up by observers around the world has resulted in this accurate prediction of the asteroid’s current orbit by scientists at the Jet Propulsion Laboratory’s Near Earth Object Program Office. Knowing the close approach is coming will allow astronomers to study the characteristics of the asteroid. A major goal will be greater refinement of its orbit so that future close approaches and even possible impacts can be predicted and prepared for.

Jaime Nomen and his colleagues at La Sagra Observatory have introduced observing strategies designed to improve the probability of discovering asteroids that larger surveys may miss. Nomen reports, “We try to find smaller objects located close to Earth that generally move at high angular speed. They may appear anywhere in the sky, even if that sky region had already been thoroughly searched just days before.”

The strategy paid off. With the new CCD telescope camera configured to shoot rapid, short exposures, Nomen and his colleagues captured 2012 DA14 as it moved across the sky at almost 11 arcseconds per minute. This is slower than a satellite but quite fast for a NEO. It’s equivalent to a lunar diameter every three hours. The asteroid was already heading away from Earth after passing the planet about a week before, and at much greater distance than next year’s encounter. Its path across the eastern sky, fast angular motion, quite faint (and fading) brightness, and high declination (far above the ecliptic plane in which most of the planets travel) could easily have allowed 2012 DA14 to escape undetected.

Planetary Society Gene Shoemaker grants are awarded to amateur observers, observers in developing countries, and professional astronomers who, with seed funding, can greatly increase their programs’ contributions to NEO research. The program, begun in 1997, is named for Gene Shoemaker, a highly respected leader in the study of impact structures, and an advocate for NEO discovery and tracking programs.

The Planetary Society supports several projects that are helping to find near Earth objects and test techniques that may allow humanity to deflect a NEO that is headed toward a potentially catastrophic impact. The Society is committed to planetary defense. “Discovery, follow-up, and characterization of asteroids enabled by our Shoemaker grants is one of our most gratifying rewards,” says Bruce Betts, the organization’s Director of Projects. “We want to help humanity avoid the world’s only preventable natural disaster. Astronomers like those at La Sagra Observatory are critical to that goal. Their discovery and next year’s close approach will result in a scientific and planetary defense treasure trove of data.”

The 2012 DA14 flyby in 2013 will also serve as a warm-up for a similar fly by in 2029 by the much larger Apophis, a 270-meter asteroid co-discovered by Shoemaker NEO grant winner Roy Tucker.

For more information, including an update on the discovery and follow-up from Jaime Nomen of La Sagra Observatory, visit

About the Planetary Society
The Planetary Society has inspired millions of people to explore other worlds and seek other life. Today, its international membership makes the non-governmental Planetary Society the largest space interest group in the world. Carl Sagan, Bruce Murray and Louis Friedman founded the Planetary Society in 1980. Bill Nye, a long time member of the Planetary Society’s Board, is now the CEO.

Planetary Society
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Pasadena, CA 91105 USA
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Fax: (626) 793-5528

Lutetia: Rare survivor from from birth of Earth

Asteroid Lutetia. Image Credit: ESA 2010 MPS for OSIRIS Team MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA

Asteroid Lutetia appears to have formed from the same material as Earth, Venus and Mercury.

New observations indicate that the asteroid Lutetia is a leftover fragment of the same original material that formed the Earth, Venus and Mercury. Astronomers have combined data from ESA’s Rosetta spacecraft, ESO’s New Technology Telescope, and NASA telescopes. They found that the properties of the asteroid closely match those of a rare kind of meteorites found on Earth and thought to have formed in the inner parts of the solar system. Lutetia must, at some point, have moved out to its current location in the main asteroid belt between Mars and Jupiter.

A team of astronomers from French and North American universities have studied the unusual asteroid Lutetia in detail at a very wide range of wavelengths to deduce its composition. Data from the OSIRIS camera on ESA’s Rosetta spacecraft, ESO’s New Technology Telescope (NTT) at the La Silla Observatory in Chile, and NASA’s Infrared Telescope Facility in Hawaii and Spitzer Space Telescope were combined to create the most complete spectrum of an asteroid ever assembled.

This spectrum of Lutetia was then compared with that of meteorites found on Earth that have been extensively studied in the laboratory. Only one type of meteorite — enstatite chondrites— was found to have properties that matched Lutetia over the full range of colors.

Enstatite chondrites are known to be material that dates from the early solar system. They are thought to have formed close to the young sun and to have been a major building block in the formation of the rocky planets, in particular the Earth, Venus and Mercury. Lutetia seems to have originated not in the main belt of asteroids, where it is now, but much closer to the sun. Pierre Vernazza (ESO), the lead author of the paper, wants to know:

How did Lutetia escape from the inner solar system and reach the main asteroid belt?

Astronomers have estimated that less than 2% of the bodies located in the region where Earth formed, ended up in the main asteroid belt. Most of the bodies of the inner solar system disappeared after a few million years as they were incorporated into the young planets that were forming. However, some of the largest, with diameters of about 100 kilometers (60 miles) or more, were ejected to safer orbits further from the sun.

Lutetia, which is about 100 kilometres across, might have been tossed out from the inner parts of the young solar system if it passed close to one of the rocky planets and thus had its orbit dramatically altered. An encounter with the young Jupiter during its migration to its current orbit could also account for the huge change in Lutetia’s orbit. Pierre Vernazza said:

We think that such an ejection must have happened to Lutetia. It ended up as an interloper in the main asteroid belt and it has been preserved there for four billion years.

Earlier studies of its color and surface properties showed that Lutetia is a very unusual and rather mysterious member of the asteroid main belt. Previous surveys have shown that similar asteroids are very rare and represent less than 1% of the asteroid population of the main belt. The new findings explain why Lutetia is different — it is a very rare survivor of the original material that formed the rocky planets. Vernazza said:

Lutetia seems to be the largest, and one of the very few, remnants of such material in the main asteroid belt. For this reason, asteroids like Lutetia represent ideal targets for future sample return missions. We could then study in detail the origin of the rocky planets, including our Earth.

via Lutetia: Rare survivor from from birth of Earth | Space | EarthSky.

Asteroid to Pass Close to Earth and the Moon

By Vickie Frantz, Staff Writer

Nov 6, 2011; 1:05 AM ET

The path of Earth is highlighted in blue, the path of the moon is highlighted in gray and the path of the asteroid is highlighted red.

The 2005 YU55 asteroid will pass within 202,000 miles of Earth on Tuesday and 149,000 miles of the moon on Wednesday.

The asteroid measures a quarter of a mile across and is the largest object to pass so close to Earth since 1976, according to NASA.

While the asteroid is passing close, scientists have no fear that it will strike either Earth or the moon.

The asteroid was first discovered in 2005 and it has been tracked by NASA ever since.

Astronomers report that the make-up of this asteroid is not rock like most of them. The 2005 YU55 asteroid is said to contain carbon-based materials and may even contain water.

Asteroids of this size rarely strike Earth. A strike occurs approximately once every 100,000 years. The asteroid Apophis, measuring approximately 882 feet across, will pass close by Earth in April 2029 and could possibly hit the Earth on its next passage in 2036.

via Asteroid to Pass Close to Earth and the Moon.