News / Science & Technology

Asteroid's Spin Intrigues Astronomers

A simulation of asteroid 2012 DA14 approaching from the south as it passes through the Earth-moon system on Feb. 15, 2013. (/NASA/JPL-Caltech)
A simulation of asteroid 2012 DA14 approaching from the south as it passes through the Earth-moon system on Feb. 15, 2013. (/NASA/JPL-Caltech)
Suzanne Presto
Astronomers hope to learn more about Asteroid 2012 DA14's features and composition as it flies past Earth at about 7.8 kilometers per second - far faster than a speeding bullet.  But that's not all they hope to discern when the object comes within 28,000 kilometers of our planet on February 15.  

Spin

Michael Busch is a planetary astronomer at the National Radio Astronomy Observatory in the southwestern U.S. state of New Mexico.  He says the direction of DA14's spin is important in predicting the way its orbit will change over time.
   
"One of the interesting things about DA14 is we expect its spin state will change as it flies by the Earth," said Busch.  "The Earth's gravity will pull slightly more on one side of the asteroid than on the other, and that will change its spin."

Speckles

The U.S. space agency's Goldstone antenna in the western state of California will beam radio waves toward the asteroid.  Busch and his team will be about 1,000 kilometers away in New Mexico, where the National Radio Astronomy Observatory operates a pair of antennas, about 400 kilometers apart.  The two antennas will receive the waves reflected off the asteroid's uneven surface.  

Busch explains parts of the asteroid will reflect the signal differently, allowing astronomers to observe so-called "speckles."  

"That pattern is random, but it moves across the Earth as the asteroid spins, so by tracking the time difference in when a different speckle arrives at a given antenna, I can figure out how fast and in what direction the asteroid is spinning," he said.

Changes in Orbit

Busch also explains that the part of the asteroid that is in view of the sun develops a hot spot that radiates heat.  This exerts a gentle, jet-like push that can speed up or slow down the asteroid.  Over time, this can significantly alter its orbit.

Astronomers with NASA, the U.S. space agency, say 2012 DA14's next notable close approach to our planet will be in 2046, and even then, it won't strike the Earth.  
Busch notes that while scientists can - for the most part - precisely predict DA14's orbit for the next century, this space rock will yield important insights into the behavior of other asteroids.  

"With the radar observations that we'll get this weekend after the close approach and the optical infrared data that is also coming in, we will be able to much better predict where DA14 in particular is going and run that orbit out much further into the future," said Busch.  "But this also lets us begin to understand the properties of the near-Earth asteroids as a population."

The U.S. space agency says, on average, an asteroid the size of 2012 DA14 gets close every 40 years and hits every 1,200 years.

You May Like

Disappointing Report on China's Economy Shakes Markets

In London and New York shares lost 3 percent, while Paris and Germany dropped around 2.4 percent More

DRC Tries Mega-Farms to Feed Population

Park at Boukanga Lonzo currently has 5,000 hectares under cultivation, crops stretching as far as eye can see, and is start of ambitious large-scale agriculture plan More

Video War, Drought Threaten Iraq's Marshlands

Areas are spawning ground for Gulf fisheries, a resting place for migrating wildfowl, source of livelihood for fishermen and herders who have called the marshes home for generations More

This forum has been closed.
Comment Sorting
Comments
     
by: jasper johns from: memphis
February 17, 2013 8:17 PM
There's a great, funny, novel about an asteroid heading toward earth and how people deal with it. It's called THE MYOSHI EFFECT.

by: Michael from: USA
February 15, 2013 9:59 AM
"Ah, yes space objects are so beautiful", holding breath and wiping sweat away with a cloth--

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Nobel Prize Winner Malala Talks to VOAi
X
August 31, 2015 2:17 AM
Nobel Peace Prize winner Malala Yousafzai met with VOA's Deewa service in Washington Sunday to talk about women’s rights and unveil a trailer for her new documentary. VOA's Katherine Gypson has more.
Video

Video Nobel Prize Winner Malala Talks to VOA

Nobel Peace Prize winner Malala Yousafzai met with VOA's Deewa service in Washington Sunday to talk about women’s rights and unveil a trailer for her new documentary. VOA's Katherine Gypson has more.
Video

Video War, Drought Threaten Iraq's Marshlands

Iraq's southern wetlands are in crisis. These areas are the spawning ground for Gulf fisheries, a resting place for migrating wildfowl, and source of livelihood for fishermen and herders. Faith Lapidus has more.
Video

Video Colombians Flee Venezuela as Border Crisis Escalates

Hundreds of Colombians have fled Venezuela since last week, amid an escalating border crisis between the two countries. Last week, Venezuelan President Nicolas Maduro ordered the closure of a key border crossing after smugglers injured three Venezuelan soldiers and a civilian. The president also ordered the deportation of Colombians who are in Venezuela illegally. Zlatica Hoke reports.
Video

Video Rebuilding New Orleans' Music Scene

Ten years after Hurricane Katrina inundated New Orleans, threatening to wash away its vibrant musical heritage along with its neighborhoods, the beat goes on. As Bronwyn Benito and Faith Lapidus report, a Musicians' Village is preserving the city's unique sound.
Video

Video In Russia, Auto Industry in Tailspin

Industry insiders say country relies too heavily on imports as inflation cuts too many consumers out of the market. Daniel Schearf has more from Moscow.
Video

Video Scientist Calls Use of Fetal Tissue in Medical Research Essential

An anti-abortion group responsible for secret recordings of workers at a women's health care organization claims the workers shown are offering baby parts for sale, a charge the organization strongly denies. While the selling of fetal tissue is against the law in the United States, abortion and the use of donated fetal tissue for medical research are both legal. VOA’s Julie Taboh reports.
Video

Video Next to Iran, Climate at Forefront of Obama Agenda

President Barack Obama this week announced new initiatives aimed at making it easier for Americans to access renewable energy sources such as solar and wind. Obama is not slowing down when it comes to pushing through climate change measures, an issue he says is the greatest threat to the country’s national security. VOA correspondent Aru Pande has more from the White House.
Video

Video Arctic Draws International Competition for Oil

A new geopolitical “Great Game” is underway in earth’s northernmost region, the Arctic, where Russia has claimed a large area for resource development and President Barack Obama recently approved Shell Oil Company’s test-drilling project in an area under U.S. control. Greg Flakus reports.
Video

Video Philippine Maritime Police: Chinese Fishermen a Threat to Country’s Security

China and the Philippines both claim maritime rights in the South China Sea.  That includes the right to fish in those waters. Jason Strother reports on how the Philippines is catching Chinese nationals it says are illegal poachers. He has the story from Palawan province.
Video

Video China's Spratly Island Building Said to Light Up the Night 'Like A City'

Southeast Asian countries claim China has illegally seized territory in the Spratly islands. It is especially a concern for a Philippine mayor who says Beijing is occupying parts of his municipality. Jason Strother reports from the capital of Palawan province, Puerto Princesa.
Video

Video Ages-old Ice Reveals Secrets of Climate Change

Ice caps don't just exist at the world's poles. There are also tropical ice caps, and the largest sits atop the Peruvian Andes - but it is melting, quickly, and may be gone within the next 20 years. George Putic reports scientists are now rushing to take samples to get at the valuable information about climate change locked in the ice.

VOA Blogs