Close approaches by Near Earth Asteroids...

[Whitters]

Asteroid 4179 Toutatis is flying past Earth this week

Space Weather News for Sept. 23, 2004
http://spaceweather.com

ASTEROID FLYBY: Asteroid 4179 Toutatis is flying past Earth this week. The weirdly tumbling space rock is close enough (4 lunar distances) and bright enough (9th magnitude) to see through backyard telescopes.  For the next few days it will scoot through the constellation Capricornus where amateur astronomers worldwide can find it.  By Sept. 29th, when Toutatis is closest to Earth, it will be visible mainly from the southern hemisphere.
Observers there can see it passing not far from the bright star Alpha Centauri. Follow the links at spaceweather.com to sky maps and detailed ephemerides.
So if your travelling south this week...

[Rick]

Mountain-sized rock passes Earth

The giant Toutatis asteroid passed by the Earth on Wednesday at a distance of less than 1.6 million km.

This is roughly four times the distance from the Earth to the Moon and closer than this 4.6km-wide rock has come to us since at least the 12th century.

The timing of closest approach was 1335GMT. Toutatis is one of the best studied asteroids in the Solar System.

More: http://news.bbc.co.uk/2/hi/science/nature/3700754.stm

[Rick]

MIT boffins plan for asteroidal doom

Researchers at MIT say they know what the near-Earth asteroid Apophis is made of, information that could be vital if we need to divert or pulverise the space-rock in 2036.

By analysing its spectrum and comparing it with meteorites that have already landed on Earth, the team has "nailed" its composition, says Richard Binzel, professor of planetary sciences in MIT's Department of Earth, Atmospheric, and Planetary Sciences (EAPS).

More: http://www.theregister.co.uk/2007/10/15/mit_asteroid/

[mickw]

Triple Asteroid Found Near Earth

The first triple asteroid near Earth has been discovered.

Astronomers have found plenty of double, or binary asteroids. Triples are known to exist, too (the first triple was found in 2005).

But the system called 2001 SN263 is the closest triple, at just 7 million miles  (11.2 million kilometers) from Earth.

It was originally found in 2001, but new observations with the radar telescope at the Arecibo Observatory in Puerto Rico reveal it is three gravitationally bound rocks.

More: http://www.space.com/scienceastronomy/080213-triple-asteroid.html

[mickw]

Near-Earth Asteroid Found to be Triplets

New radar observations have revealed that a near-Earth asteroid is actually three rocks.

The system, asteroid 1994 CC, was imaged by NASA's Goldstone Solar System Radar on June 12 and 14. The results were released this week.

While most asteroids roam in a belt between Mars and Jupiter, some are kicked or drawn inward and cross our orbital path around the sun. Some 15 percent of these near-Earth asteroids are binaries. Even fewer, a mere one percent, are triples.

More:   http://www.space.com/scienceastronomy/090807-triple-asteroid.html

[mickw]

U.S. Military in Talks to Share Fireball Data from Secret Satellites

For decades, the U.S. Department of Defense has operated classified spacecraft loaded with high-tech gear to carry out a range of reconnaissance duties. But the satellites have also spotted the high-altitude explosions of natural fireballs that routinely dive into the Earth's atmosphere, and talks are under way to offer scientists access to that data.
In the past, the data on the fireballs, caused by small asteroids called bolides, was shared with the near-Earth object (NEO) science community, information deemed ideal for understanding the size of small NEOs and the hazard they pose.

More:   Bolides

[Rick]

Near-Earth Asteroid 2012 DA14 to Miss Earth on February 15, 2013

Discovered by the LaSagra observatory in southern Spain, the small asteroid 2012 DA14 will pass within about 3.5 Earth radii of the Earth's surface on February 15, 2013. Although its size is not well determined, this near-Earth asteroid is thought to be about 45 meters in diameter. Asteroid 2012 DA14 will pass inside the geosynchronous satellite ring, located about 35,800 km above the equator. Its orbit about the sun can bring it no closer to the Earth's surface than 3.2 Earth radii on February 15, 2013.

More: http://neo.jpl.nasa.gov/news/news174.html

[Rick]

NASA Radar Images Asteroid 2007 PA8

Scientists working with NASA's 230-foot-wide (70-meter) Deep Space Network antenna at Goldstone, Calif., have obtained several radar images depicting near-Earth asteroid 2007 PA8. The images were generated from data collected at Goldstone on Oct. 28, 29 and 30, 2012. The asteroid's distance from Earth on Oct. 28 was 6.5 million miles (10 million kilometers). The asteroid's distance to Earth was 5.6 million miles (9 million kilometers) on Oct. 30. The perspective in the images is analogous to seeing the asteroid from above its north pole. Each of the three images is shown at the same scale.

The radar images of asteroid 2007 PA8 indicate that it is an elongated, irregularly shaped object approximately one mile (1.6 kilometers) wide, with ridges and perhaps craters. The data also indicate that 2007 PA8 rotates very slowly, roughly once every three to four days.

More: http://www.jpl.nasa.gov/news/news.php?release=2012-350

[Rick]

Asteroid Toutatis Slowly Tumbles by Earth

Scientists working with NASA's 230-foot-wide (70-meter) Deep Space Network antenna at Goldstone, Calif., have generated a series of radar data images of a three-mile-long (4.8-kilometer) asteroid that made its closest approach to Earth on Dec. 12, 2012.

The images that make up the movie clip were generated with data taken on Dec. 12 and 13, 2012. On Dec. 12, the day of its closest approach to Earth, Toutatis was about 18 lunar distances, 4.3 million miles (6.9 million kilometers) from Earth. On Dec. 13, the asteroid was about 4.4 million miles (7 million kilometers), or about 18.2 lunar distances.

More, including movie link: http://www.jpl.nasa.gov/news/news.php?release=2012-397

[Rick]

Record Setting Asteroid Flyby

Talk about a close shave. On Feb. 15th an asteroid about half the size of a football field will fly past Earth only 17,200 miles above our planet's surface. There's no danger of a collision, but the space rock, designated 2012 DA14, has NASA's attention.

"This is a record-setting close approach," says Don Yeomans of NASA's Near Earth Object Program at JPL. "Since regular sky surveys began in the 1990s, we've never seen an object this big get so close to Earth."

More: http://science.nasa.gov/science-news/science-at-nasa/2013/28jan_2012da/

[Rick]

Goldstone Radar Snags Images of Asteroid 2013 ET

A sequence of radar images of asteroid 2013 ET was obtained on March 10, 2013, by NASA scientists using the 230-foot (70-meter) Deep Space Network antenna at Goldstone, Calif., when the asteroid was about 693,000 miles (1.1 million kilometers) from Earth, which is 2.9 lunar distances.

The radar imagery suggests the irregularly shaped object is at least 130 feet (40 meters) wide. The 18 radar images were taken over a span of 1.3 hours. During that interval, the asteroid completed only a fraction of one rotation, suggesting that it rotates once every few hours.

More: http://www.jpl.nasa.gov/news/news.php?release=2013-101

[Rick]

NASA Radar Reveals Asteroid Has Its Own Moon

A sequence of radar images of asteroid 1998 QE2 was obtained on the evening of May 29, 2013, by NASA scientists using the 230-foot (70-meter) Deep Space Network antenna at Goldstone, Calif., when the asteroid was about 3.75 million miles (6 million kilometers) from Earth, which is 15.6 lunar distances.

The radar imagery revealed that 1998 QE2 is a binary asteroid. In the near-Earth population, about 16 percent of asteroids that are about 655 feet (200 meters) or larger are binary or triple systems. Radar images suggest that the main body, or primary, is approximately 1.7 miles (2.7 kilometers) in diameter and has a rotation period of less than four hours. Also revealed in the radar imagery of 1998 QE2 are several dark surface features that suggest large concavities. The preliminary estimate for the size of the asteroid's satellite, or moon, is approximately 2,000 feet (600 meters) wide.

More: http://www.jpl.nasa.gov/news/news.php?release=2013-182

[Rick]

Radar Movies Highlight Asteroid 1998 QE2 and Its Moon

Scientists working with NASA's 230-foot-wide (70-meter) Deep Space Network antenna at Goldstone, Calif., have released a second, longer, more refined movie clip of asteroid 1998 QE2 and its moon. The 55 individual images used in the movie were generated from data collected at Goldstone on June 1, 2013.

Each of the individual images obtained on June 1, 2013, required about five minutes of data collection by the Goldstone radar. At the time of the observations that day, asteroid 1998 QE2 was about 3.75 million miles (6 million kilometers) from Earth. The resolution is about 125 feet (38 meters) per pixel.

With additional radar images and time for analysis, NASA scientists have been able to refine their estimates of the asteroid's size and rotation. The data indicate the main, or primary body, is approximately 1.9 miles (3 kilometers) in diameter and has a rotation period of about five hours.

More: http://www.jpl.nasa.gov/news/news.php?release=2013-193

[Rick]

Radar Images of Asteroid 2005 WK4

A collage of radar images of near-Earth asteroid 2005 WK4 was generated by NASA scientists using the 230-foot (70-meter) Deep Space Network antenna at Goldstone, Calif., on Aug. 8, 2013.

The asteroid is between 660 and 980 feet (200 and 300 meters) in diameter; it has a rounded and slightly asymmetric shape. As it rotates, a number of features are evident that suggest the presence of some flat regions and a bulge near the equator.

More: http://www.jpl.nasa.gov/news/news.php?release=2013-254

[Rick]

Asteroid 2013 TV135 - A Reality Check

Newly discovered asteroid 2013 TV135 made a close approach to Earth on Sept. 16 when it came within about 4.2 million miles (6.7 million kilometers). The asteroid is initially estimated to be about 1,300 feet (400 meters) in size and its orbit carries it as far out as about three quarters of the distance to Jupiter's orbit and as close to the sun as the Earth's orbit. It was discovered on Oct. 8, 2013, by astronomers working at the Crimean Astrophysical Observatory in the Ukraine. As of Oct. 14, asteroid 2013 TV135 is one of 10,332 Near-Earth objects that have been discovered.

With only a week of observations for an orbital period that spans almost 4 years its future orbital path is still quite uncertain, but this asteroid could be back in the Earth's neighborhood in 2032. However, the Near-Earth Object Program Office states the probability this asteroid could then impact Earth is only 1-in 63,000. The object should be easily observable in the coming months and once additional observations are provided to the Minor Planet Center in Cambridge Massachusetts, the initial orbit calculations will be improved and the most likely result will be a dramatic reduction, or complete elimination, of any risk of Earth impact.

More: http://neo.jpl.nasa.gov/news/news180.html