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#Asteroid2012DA14 brushes past Earth

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asteroid-2012-da14-flyby-persepective

Asteroid 2012 DA14 brushed past Earth early Saturday morning (IST) causing no damage to any satellite. It passed inside the ring of geosynchronous weather and communications satellites. ”The asteroid safely passed our planet 17,500 miles above Indonesia,” NASA said.

The newly discovered asteroid, about half the size of a football field, was tracked by NASA and various space centres, giving scientists a rare opportunity for close-up observations without launching a probe.

At its closest approach, which occurred at 1924 GMT or 0055 IST, the asteroid passed about 17,200 miles (27,520 km) above the planet traveling at 13 km per second, bringing it nearer than the networks of television and weather satellites that ring the planet.

Although Asteroid 2012 DA14 is the largest known object of its size to pass this close, scientists had predicted that there would be no chance of an impact.

Currently, DA14 matches Earth’s year-long orbit around the sun, but after today’s encounter its flight path will change, said astronomer Donald Yeomans, with NASA’s Jet Propulsion Laboratory in Pasadena, California.

“The close approach will perturb its orbit so that actually instead of having an orbital period of one year, it’ll lose a couple of months,” Yeomans said. “The Earth is going to put this one in an orbit that is considerably safer,” he said.

For scientists, DA14 presented a rare, albeit short, opportunity to study an asteroid close-up. In addition to trying to determine what minerals it contains, which is of potential commercial interest as well as scientific, astronomers want to learn more about the asteroid’s spin rate. The information not only will be useful to plotting DA14′s future visits but could help engineers develop techniques to thwart more threatening asteroids.

Phew! Asteroid to miss Earth in 2040, NASA says

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On a day when global doomsday predictions failed to pan out, NASA had more good news for the Earth: An asteroid feared to be on a collision course with our planet no longer poses a threat.

The position data obtained for near-Earth asteroid 2011 AG5 in October was used to reduce its future orbital uncertainties.

Uncertainties about the orbit of the asteroid, known as 2011 AG5, previously allowed for a less than a 1% chance it would hit the Earth in February 2040, NASA said.

STORY HIGHLIGHTS

  • The asteroid previously had a 0.2% chance of hitting the Earth

  • More observation by astronomers in Hawaii shows no risk of collision

  • A collision would have released about 100 megatons of energy

  • Observing the asteroid wasn’t easy

To narrow down the asteroid’s future course, NASA put out a call for more observation. Astronomers from the University of Hawaii at Manoa took up the task and managed to observe the asteroid over several days in October.

“An analysis of the new data conducted by NASA’s Near-Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, California, shows that the risk of collision in 2040 has been eliminated,” NASA declared Friday.

The new observations, made with the Gemini 8-meter telescope in Mauna Kea, Hawaii, reduce the orbit uncertainties by more than a factor of 60. That means the Earth’s position in February 2040 is not in range of the asteroid’s possible future paths.

The asteroid, which is 140 meters (460 feet) in diameter, will get no closer to Earth than 890,000 kilometers (553,000 miles), or more than twice the distance to the moon, NASA said.

A collision with Earth would have released about 100 megatons of energy, several thousand times more powerful than the atomic bombs that ended World War II, according to the Gemini Observatory.

Observing the asteroid wasn’t easy, said David Tholen, an astronomer at the University of Hawaii Institute for Astronomy.

The asteroid’s position was very close to the sun, so astronomers had to observe it when the sky was dark. Tholen told CNN there was about a half-hour between when the asteroid got high enough in the sky for the telescope to point at it and before the sky became too light to observe it.

Because the astronomers were looking at the asteroid low in the sky, they were viewing it through a lot of atmosphere, which scattered some of the light and made the object fainter, he said.

“The second effect is the turbulence of the atmosphere makes things fainter,” Tholen said. “We had to keep trying over and over until we got one of those nights when the atmosphere was calm.”

Tholen and the team also discovered the asteroid is elongated, so that as it rotates, its brightness changes. That was another challenge for the astronomers: Because they didn’t know the asteroid’s rotation period, they didn’t know when it would wax and wane, and when it would grow too faint to see.

“This object was changing its brightness by a factor of three or four — it was just enormously variable,” Tholen said. “It was hit and miss depending on which night you observed it.”

Many predicted the end of the world would come Friday, the day on which a long phase in the ancient Mayan calendar came to an end. Some believe the day actually comes Sunday.

Modern-day Mayans say the end of the calendar phase doesn’t mean the end of the world — just the end of an era, and the start of a new one.

Bus-Size Asteroid Buzzes Earth in Close Flyby

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A small asteroid the size of a city bus zoomed between Earth and the moon’s orbit Friday (Jan. 27) just days after its discovery, but it never posed a threat to our planet, NASA says.

The asteroid 2012 BX34 passed within 36,750 miles (59,044 kilometers) of Earth when it made its closest approach at 10:30 a.m. EST (1530 GMT). The space rock is about 37 feet (11 meters) wide and would have broke apart in Earth’s atmosphere long before it reached the ground, if it had reached the planet at all, NASA scientists said.

“Asteroid 2012 BX34 is small,” astronomers with NASA’s Asteroid Watch at the Jet Propulsion Laboratory in Pasadena, Calif., said in a Twitter message. “It wouldn’t get through our atmosphere intact even if it dared to try.”

The space rock passed Earth at a distance that is only about 0.17 times that between the Earth and the moon. For comparison, the moon typically orbits Earth at a distance of about 240,000 miles (386,000 km).

“Asteroids this small are hard to spot, & luckily they pose the least concern,” Asteroid Watch scientists explained. “Our goal is to find the bigger ones.” 

asteroid 2012bx34 close approach
The newly discovered asteroid 2012 BX34 (whose orbit is represented by the blue line) will come within 0.17 lunar distances of Earth on Jan. 27, 2012, experts say.
CREDIT: NASA/JPL-Caltech

A small asteroid the size of a city bus zoomed between Earth and the moon’s orbit Friday (Jan. 27) just days after its discovery, but it never posed a threat to our planet, NASA says.

The asteroid 2012 BX34 passed within 36,750 miles (59,044 kilometers) of Earth when it made its closest approach at 10:30 a.m. EST (1530 GMT). The space rock is about 37 feet (11 meters) wide and would have broke apart in Earth’s atmosphere long before it reached the ground, if it had reached the planet at all, NASA scientists said.

“Asteroid 2012 BX34 is small,” astronomers with NASA’s Asteroid Watch at the Jet Propulsion Laboratory in Pasadena, Calif., said in a Twitter message. “It wouldn’t get through our atmosphere intact even if it dared to try.”

The space rock passed Earth at a distance that is only about 0.17 times that between the Earth and the moon. For comparison, the moon typically orbits Earth at a distance of about 240,000 miles (386,000 km).

 ”Asteroids this small are hard to spot, & luckily they pose the least concern,” Asteroid Watch scientists explained. “Our goal is to find the bigger ones.” [Video and image of asteroid 2012 BX34's orbit]

In September, NASA announced that it has spotted about 90 percent of the largest asteroids (the size of a mountain or bigger) that can come near Earth. About 911 such giant space rocks have been confirmed. Astronomers estimate there are about 981 big near-Earth objects that occasionally creep close to our planet.

Asteroid 2012 BX34 was the second space rock to fly relatively close by Earth this week, Asteroid Watch scientists said. On Jan. 23, another small asteroid — called 2012 BS1 — passed by the planet at a range of about 745,000 miles (1.2 million km), which is about 3.1 times the Earth-moon distance.

“Asteroid 2012 BS1 is so small (about 7 meters) it would disintegrate in our atmosphere if it were to come close to Earth,” the Asteroid Watch team wrote.

Astronomers with NASA and other science teams routinely scan the skies in search of near-Earth asteroids that could pose a danger to the planet. Experts estimate that asteroids about 460 feet (140 m) across and bigger can cause widespread devastation near their impact sites, though a larger space rock would be required to cause destruction on a global scale.

This week, scientists from around the world are also discussing how Earth should respond to the threat of an asteroid impact. The so-called NEOShield project is a European commission led by the German Aerospace Center and includes scientists from universities and industrial partners in Germany, France, the United Kingdom, Spain, the United States and Russia.

AUTHOR – Tariq Malik, SPACE.com Managing Editor

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