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

Taliban's New Leader Says Jihad Will Continue

Top US Afghan diplomat also meets with Pakistani, Afghan officials following news of Mullah Omar's death More

Video US Landmark Pushes Endangered Species

People gathered in streets, on rooftops in Manhattan to see image highlights that covered 33 floors of Empire State Building More

World’s Widest Suspension Bridge Being Built Over Bosphorus

Once built, Yavuz Sultan Selim Bridge will span 2 kilometers with about 1.5 kilometers over water, and will be longest suspension bridge in world carrying rail system 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.
Astronauts Train Underwater for Deep Space Missionsi
|| 0:00:00
...    
🔇
X
George Putic
July 30, 2015 8:59 PM
Manned deep space missions are still a long way off, but space agencies are already testing procedures, equipment and human stamina for operations in extreme environment conditions. Small groups of astronauts take turns in spending days in an underwater lab, off Florida’s southern coast, simulating future missions to some remote world. VOA’s George Putic reports.
Video

Video Astronauts Train Underwater for Deep Space Missions

Manned deep space missions are still a long way off, but space agencies are already testing procedures, equipment and human stamina for operations in extreme environment conditions. Small groups of astronauts take turns in spending days in an underwater lab, off Florida’s southern coast, simulating future missions to some remote world. VOA’s George Putic reports.
Video

Video Civil Rights Leaders Struggled to Achieve Voting Rights Act

Fifty years ago, lawmakers approved, and U.S. President Lyndon Johnson signed, the Voting Rights Act of 1965. The measure outlawed racial discrimination in voting, giving millions of blacks in many parts of the southern United States federal enforcement of the right to vote. Correspondent Chris Simkins introduces us to some civil rights leaders who were on the front lines in the struggle for voting rights.
Video

Video Booming London Property a ‘Haven for Dirty Money’

Billions of dollars of so-called ‘dirty money’ from the proceeds of crime - especially from Russia - are being laundered through the London property market, according to anti-corruption activists. As Henry Ridgwell reports from the British capital, the government has pledged to crack down on the practice.
Video

Video Hometown of Boy Scouts of America Founder Reacts to Gay Leader Decision

Ottawa, Illinois, is the hometown of W.D. Boyce, who founded the Boy Scouts of America in 1910. In Ottawa, where Scouting remains an important part of the legacy of the community, the end of the organization's ban on openly gay adult leaders was seen as inevitable. VOA's Kane Farabaugh reports.
Video

Video 'Metal Muscles' Flex a New Bionic Hand

Artificial limbs, including the most complex of them – the human hand – are getting more life-like and useful due to constant advances in tiny hydraulic, pneumatic and electric motors called actuators. But now, as VOA’s George Putic reports, scientists in Germany say the future of the prosthetic hand may lie not in motors but in wires that can ‘remember’ their shape.
Video

Video Russia Accused of Abusing Interpol to Pursue Opponents

A British pro-democracy group has accused Russia of abusing the global law enforcement agency Interpol by requesting the arrest and extradition of political opponents. A new report by the group notes such requests can mean the accused are unable to travel and are often unable to open bank accounts. VOA's Henry Ridgwell reports.
Video

Video 'Positive Atmosphere' Points Toward TPP Trade Deal in Hawaii

Talks on a major new trade agreement among 12 Pacific Rim nations are said to be nearing completion in Hawaii. Some trade experts say the "positive atmosphere" at the discussions could mean a deal is within reach, but there is still hard bargaining to be done over many issues and products, including U.S. drugs and Japanese rice. VOA's Jim Randle reports.
Video

Video Genome Initiative Urgently Moves to Freeze DNA Before Species Go Extinct

Earth is in the midst of its sixth mass extinction. The last such event was caused by an asteroid 66 million years ago. It killed off the dinosaurs and practically everything else. So scientists are in a race against time to classify the estimated 11 million species alive today. So far only 2 million are described by science, and researchers are worried many will disappear before they even have a name. VOA’s Rosanne Skirble reports.
Video

Video Scientists: One-Dose Malaria Cure is Possible

Scientists have long been trying to develop an effective protection and cure for malaria - one of the deadliest diseases that affects people in tropical areas, especially children. As the World Health Organization announces plans to begin clinical trials of a promising new vaccine, scientists in South Africa report that they too are at an important threshold. George Putic reports, they are testing a compound that could be a single-dose cure for malaria.
Video

Video 'New York' Magazine Features 35 Cosby Accusers

The latest issue of 'New York' magazine features 35 women who say they were drugged and raped by film and television celebrity Bill Cosby. The women are aged from 44 to 80 and come from different walks of life and races. The magazine interviewed each of them separately, but Zlatica Hoke reports their stories are similar.
Video

Video US Calls Fight Against Human Trafficking a Must Win

The United States is promising not to give up its fight against what Secretary of State John Kerry calls the “scourge” of modern slavery. Officials released the country’s annual human trafficking report Monday – a report that’s being met with some criticism. VOA’s National Security correspondent Jeff Seldin has more from the State Department.
Video

Video Washington DC Underground Streetcar Station to Become Arts Venue

Abandoned more than 50 years ago, the underground streetcar station in Washington D.C.’s historic DuPont Circle district is about to be reborn. The plan calls for turning the spacious underground platforms - once meant to be a transportation hub, - into a unique space for art exhibitions, presentations, concerts and even a film set. Roman Mamonov has more from beneath the streets of the U.S. capital. Joy Wagner narrates his report.
Video

Video Europe’s Twin Crises Collide in Greece as Migrant Numbers Soar

Greece has replaced Italy as the main gateway for migrants into Europe, with more than 100,000 arrivals in the first six months of 2015. Many want to move further into Europe and escape Greece’s economic crisis, but they face widespread dangers on the journey overland through the Balkans. VOA's Henry Ridgwell reports.
Video

Video Stink Intensifies as Lebanon’s Trash Crisis Continues

After the closure of a major rubbish dump a week ago, the streets of Beirut are filling up with trash. Having failed to draw up a plan B, politicians are struggling to deal with the problem. John Owens has more for VOA from Beirut.
Video

Video Paris Rolls Out Blueprint to Fight Climate Change

A U.N. climate conference in December aims to produce an ambitious agreement to fight heat-trapping greenhouse gases. But many local governments are not waiting, and have drafted their own climate action plans. That’s the case with Paris — which is getting special attention, since it’s hosting the climate summit. Lisa Bryant takes a look for VOA at the transformation of the French capital into an eco-city.

VOA Blogs