The Science Seat: Why asteroids don’t surprise us anymore
Don Yeomans studies asteroids at NASA's Jet Propulsion Laboratory.
February 15th, 2013
04:38 PM ET

The Science Seat: Why asteroids don’t surprise us anymore

By Matthew Rehbein, CNN

A lot of scientists dream of making a discovery that will make an impact. Planetary scientist Don Yeomans is not one of them.

Yeomans manages the Near-Earth Object Program at NASA's Jet Propulsion Laboratory, which means he spends his days monitoring the thousands of asteroids and comets swirling around the solar system, making sure that none of the bigger ones are on a collision course with Earth. He and his team play a “Men in Black” type of role, constantly finding, assessing and ruling out threats to the planet from outer space.

The importance of Yeomans’ work was especially in the spotlight Friday, when an asteroid about half the length of a football field passed relatively close to Earth - closer than many of our orbiting communications satellites - going roughly eight times as fast as a speeding bullet.

Yeomans and his team were among those who helped forecast this event. He assured us that it would not hit, and it looks like he was right.

CNN Light Years recently spoke with him about his work and how it might impact - not literally - humankind’s efforts in space in the future. Below is an edited transcript of this interview, conducted via e-mail.

CNN: What made you want to get into astronomy?

Yeomans: I had a particularly engaging science teacher at Middlebury College in Vermont and he turned me on to astronomy and I decided to go to grad school at the University of Maryland as a result. The topic of comets and asteroids appealed to me so I zeroed in on that and, in particular, their motions, where they are and where they’re going to be.

CNN: What’s a normal day at work for you?

Yeomans: My work day usually begins with a check of our automatic monitoring systems to see if any new near-Earth objects have been discovered and whether or not one of them will make a close Earth approach in the near future. We closely interact with the Minor Planet Center in Cambridge, Massachusetts, the radar astronomers and a small army of amateur and professional astronomers to make sure future close-Earth approaches of asteroids and comets are observed with as many techniques and tools as possible.

CNN: In addition to monitoring surrounding near-Earth objects for potential threats, why else is it important for us to know more about asteroids and comets?

Yeomans: Near-Earth objects are important for a number of reasons beyond the threat issue. They are the leftover bits and pieces from the solar system formation process so if we wish to understand the chemical and thermal environment under which our solar system formed 4.6 billion years ago, then we’d like to study near-Earth objects since they have not changed much since this formation process.

These objects likely brought to the early Earth much of the water and carbon-based materials that allowed life to form more than 3.5 billion years ago and subsequent impacts allowed only the most adaptable species - like mammals - to evolve further. We humans may well exist atop the food chain as a result of near-Earth objects.

Finally, near-Earth objects may one day provide the mineral and metal resources for interplanetary structures. In addition, water resources can be extracted from hydrated minerals in some asteroids. The water, in turn, can be broken down into oxygen and hydrogen, the most efficient form of rocket fuel.

One day, near-Earth objects may serve as the fueling stations and watering holes for interplanetary travel.

CNN: This Friday, your team has announced that a relatively large asteroid is going to pass quite close to Earth. Scientists are going to be ‘pinging’ it with radar - what do you hope to learn from observing this event?

Yeomans: [The asteroid] 2012 DA14 is approximately 45 meters in diameter and will pass within 17,200 miles above the Earth’s surface on Friday. Shortly after the close approach, the two planetary radars will observe this object to provide precise position and velocity information for orbit improvement. The radar data can also provide information on the asteroid’s rotation characteristics, its shape and size; and the radars can check for any small moons.

CNN: If you were to discover that a near-Earth object was going to or likely to make a significant impact - that is, cause significant damage or threaten human life - what would you do?

Yeomans: The three most important goals for mitigating an Earth-threatening asteroid would be to find it early, find it early and find it early. That is NASA’s goal. With enough time, the threatening asteroid could be deflected with a number of techniques.

To my mind, the simplest, least complex and, hence, best technique for deflection would use an impacting massive spacecraft carried out well in advance of the predicted [Earth] impact. The impacting spacecraft would slightly alter the asteroid’s orbit period so that in 10 or 20 years or so when the asteroid was predicted to impact Earth, it would miss by a wide margin.

We actually had an Earth impact in October of 2008 when a 4-meter-sized asteroid, 2008 TC3, caused an air blast over northern Sudan. The object was discovered less than a day prior to impact. Thanks to many amateur and professional astronomers, hundreds of additional observations were provided and we worked hard to improve the orbit for this object.

Steve Chesley and Paul Chodas, from our office, provided very accurate predictions for the time and place of this impact, and NASA sent out announcements of this impending impact a few hours in advance of the impact itself. This announcement was sent to a number of agencies, as well as the White House.

CNN: You have a pretty accomplished career thus far. What still excites you about what you do every day?

Yeomans: Mother Nature keeps firing shots across Earth’s bow in the form of near-Earth objects, and that keeps my days busy. We often have to provide predictions, request additional observations and inform the public about each new object that will approach the Earth. For a few of these objects, we often cannot immediately rule out a future Earth impact until new observations are used to improve the object’s orbit.

Before NASA’s comprehensive program on near-Earth objects began in the mid-1990’s, we were blissfully unaware of the objects whizzing by the Earth. Now we are looking [at] and tracking these objects. The chances of our being taken by surprise has been reduced substantially.

There’s more to be done, of course, but NASA’s near-Earth object program has substantially reduced the risk from a strike by a near-Earth object. Now we know about most of the large near-Earth objects and we’ve determined that none of these known objects represent a near-term threat.

The field of near-Earth objects is such an interesting topic, from a number of points of view, that I always find this work exciting. I look forward to going “to work.”

CNN: What’s the next big achievement in space you’d like to see?

Yeomans: In April 2010, President Obama requested that a NASA goal should be to carry out a human exploration of a near-Earth asteroid as a stepping stone to the far more difficult human exploration of Mars. That is, the technologies and techniques required for a human exploration of Mars could be carried out at a near-Earth object and this type of mission would only require a trip time of a few month - rather than a few years. One of our goals is to find a suitable target [asteroid] for a mission of this type.

Photos: All about asteroids

CNN: What advice would you offer to aspiring scientists?

Yeomans: That’s an easy one. Find a topic that fascinates you, then pursue it with bulldog tenacity. That way, you’ll love your job and never have a single day of “work.” For myself, I can’t believe I’m being paid to have this much fun.

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soundoff (31 Responses)
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    April 9, 2013 at 11:50 pm |
  2. nerp

    Well said.

    February 20, 2013 at 10:22 pm |
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    February 17, 2013 at 4:37 pm |
  4. H. B.

    I'm what's called an "armchair astronomer," which means I do NOT have the technical expertise of the real ones, but I DO have extensive knowledge about the cosmos and how things do what they do.

    Most comments here seem to be from people who think they have the STANDING to make judgments. The fact that this man loves his job shows that he IS working at it with "bulldog tenacity." The commenter who thinks it has to be either/or is a dufus.

    And those who call Mr. Yeomans a fool ought to look in a mirror sometime. They are judging the strike in Russia as something equivalent to the asteroid that flew by. Something Mr. Yeomans and his colleagues were too incompetent to see and measure its orbit to predict the Russian hit. While it was said – more than once – that there was absolutely NO connection between them, people still drew connections, from the depths of their fifth-grade knowledge.

    Nor did many pay attention to the fact that astronomers have SAID it is very difficult to find, track and predict the movements of smaller objects, like the Russian meteroid. People either don't read, or don't like to accept what they did read. They prefer their own lamebrained conclusions. Without even knowing the limitations of our technology to detect these smaller objects, they leap right into condemnations. I think they like being that way.

    They never said to forget about the threats from near-Earth objects. What they DID say was that this flyby asteroid was nothing to worry about. Which is true. They also have a good handle on others further out that might come our way, but even with the preliminary data they have gotten, none appear to be looking at Earth in their cross-hairs, and that, too, should comfort some people. We're not looking at an extinction event from a meteor or asteroid for several decades, at the very least.

    I think some of these ignorant-and-proud folks actually WANT such a disaster to hit us – some, because they drool for Armageddon, but many want it just because they think it would be exciting. Ahh...exciting? Having a "hit" big enough could block out the sun for weeks with dust, threatening everyone's food supply, perhaps for ten years. I'd call that something NOT to look forward to. But people WILL be people, and most of them are incredibly, abysmally IGNORANT. And arrogant about it, too.

    If you don't know about these things, why not set about learning more, rather than making snarky comments that make you look stupid? BTW, "duck and cover" is useless if you're near a major impact.

    I don't imagine any of them would pay any attention to what I've written, either. Most people seem to live in a kind of "dream-time," in which reality is whatever THEY want it to be.

    That's scarier than an asteroid on a direct hit trajectory.

    Everything I read in Mr. Yeomans' writing is in complete concordance with the knowledge I've had for years. He's a highly-trained man, doing a job that would bore most people silly. And he's loving it, which usually means he's giving it his all.

    And people find fault with these things?

    Rather than getting snarky, why don't some of you go to the library, or buy a few books on astronomy and cosmology at the layman's level? Isaac Asimov wrote some really good stuff. Though decades old, most of it is still as valid today as it ever was. Then you'd be able to learn something, and would no longer need to shoot your mouths off in order to feel important.

    Mr. Yeomans, I'm glad you are on the job on this project. I hope you enjoy it more every day, and I hope in time you'll learn a bunch about the way the solar system formed. Some of the un-brained people here hate you because you are productive, intelligent, educated and enjoy your highly technical work. That's because you are everything that they are NOT. Which is their problem, not yours. Keep on keeping on.

    I'd LOVE to sit down with you for a few hours with a BIG pot of coffee in front of us. I'd have nothing but questions. But I'd be glad to provide the cookies.

    February 15, 2013 at 9:08 pm |
  5. Jer_DC

    This is finally starting to look like a typical internet discussion board. Good work.

    February 15, 2013 at 3:53 pm |
    • Men in Black

      Agreed! I was starting to get worried.

      February 15, 2013 at 3:58 pm |
  6. authorajpalm

    Reblogged this on authorajpalm and commented:
    My friend Rose is pretty patriotic and whenever the opportunity arises, she likes to brag about things the United States are doing damn well. Despite how horrible things seem to be, she remains faithful to her country, which I admire, and I find it fascinating how NASA tends to be her top reasons as to why the U.S. is still number one. This article testifies to the importance of the work these scientists are doing on a daily basis. It's admirable.

    February 15, 2013 at 3:50 pm |
  7. Hen In Black

    Yeomans LOL! God well prevented us, so Stop fooling yourself and others about scientist can prevent asteroid from hitting earth., the only thing that scientist can do is watching it before it strike!!!! and about Mars let's focus on fixing our home earth before we start ruining the universe.

    February 15, 2013 at 3:25 pm |
  8. Griffin

    This is all well and good but as evidence by the Chelyabinsk it falls far short of ensuring public safety.

    If a meteoroid 50 feet wide can cause 700+ injuries as a complete surprise we are not in any way safe.

    We might not be surprised about Astroids due to early detection abilities but that does not mean we have nothing to worry about in regards to space objects causing catastrophic death and damage. All of these "don't worry about asteroids" articles are inappropriately inferring we are therefore somehow safe and don't need to do further work.

    February 15, 2013 at 3:04 pm |
    • Mark

      The task of detecting, indexing, and tracking near-earth objects is a long-term progressive undertaking. As of 1990, as stated in the article, we were blissfully unaware that we live on a planet that moves through a cosmic shooting gallery. Our efforts over the past two decades have enlightened us, not only to what is really out there, but also to the potential for humans to protect all earthlings from cosmic impact. We can do this by finding out is out there, how these objects behave and determine what their futures will be with respect to us here on Earth. A time will come when we will have cataloged nearly all the potentially threatening asteroids. Right now, our technologies permit us to gain a good record for the largest and middle-sized asteroids. Chelyabinsk was a very visible reminder that we must do better and we will. Our detection capabilities improve with each passing year and the time will come when the 17-meter objects do not become known to us only upon arrival but several years ahead of time. Armed with this knowledge, we will be able to mount a defense and deflection system that will be implemented against it to send out of our way well before impact. This is no fools errand, but a vital and necessary program that our children's grandchildren will be happy we had the foresight to launch.

      February 27, 2013 at 7:28 pm |
  9. Jeffrey Root

    The people commenting on this board are idiots. What hit in Russia was not an asteroid, but a meteor, much smaller in size.

    February 15, 2013 at 2:48 pm |
    • Jer_DC

      Most people commenting on any news board are idiots. Is this your first time on the internet?

      February 15, 2013 at 2:54 pm |
      • Mark

        The Chelyabinsk object was indeed an asteroid. As it drifted in near-earth orbit it was asteroid. Upon its entry into Earth's atmosphere, this asteroid became a meteor, then a fireball as it became superheated from the friction with the air against it at 40km/sec.

        February 27, 2013 at 7:22 pm |
    • Men in Black

      Jeff – here's some education for free – a meteor is an asteroid or other object that burns and vaporizes upon entry into the Earth's atmosphere; meteors are commonly known as "shooting stars." If a meteor survives the plunge through the atmosphere and lands on the surface, it's known as a meteorite. There's no universally accepted, hard-and-fast definition (based on size or any other characteristic) that distinguishes a meteoroid from an asteroid — they're simply smaller than asteroids.

      February 15, 2013 at 3:01 pm |
      • Jer_DC

        "The size of the object before hitting the atmosphere was about 49 feet (15 meters) and had a mass of about 7,000 tons... about one-third the diameter of asteroid 2012 DA14."

        February 15, 2013 at 3:15 pm |
  10. Jer_DC

    Yeomans : “…so that in 10 or 20 years or so when the asteroid was predicted to impact Earth, it would miss by a wide margin.”

    The warning window on these collision-course asteroids, or near misses, like 2012 DA14 and 2008 TC3, has been at most about a day. It seems that most of these near-Earth orbit asteroids aren’t detected until they either pass near the Earth, or after they crash into it. 20 years warning? I don't get it.

    February 15, 2013 at 2:47 pm |
  11. Men in Black

    Last quote in article is classic... maybe he should focus on having a little less fun and more "bulldog tenacity".

    February 15, 2013 at 2:36 pm |
  12. stambo

    Irony. Here is an article where a 'scientist' pats himself on the back and tells us all once again they understand everything...and then 'BANG!' reality hits. What a maroon!

    February 15, 2013 at 2:30 pm |
  13. Mike

    If this guy thinks there's not chance today's asteroid will hit the earth...time to duck and cover!

    February 15, 2013 at 2:26 pm |
  14. Mike

    Rather ironic timing, isn't it? Nope...still don't see it. BOOM!!!

    February 15, 2013 at 2:24 pm |
  15. jon

    It is long overdue that the human race needs to find a way to inhabit Mars as an alternative in case there is a life ending asteroid impact on Earth. The human race is far too advanced to allow ourselves to become extinct like the dinosaurs because we didn't prepare enough with the knowledge and technology we possess today. We are too intelligent and valuable to allow a cosmic event to end our species. Our ancestors did everything they could to survive and we need to learn how to survive on other planets and eventually other solar systems to carry on our legacy and existence in the universe.

    February 15, 2013 at 2:20 pm |
    • TAK

      But it is a bit of a paradox that in order to reduce the risk of extinction from an asteroid impact we should establish a colony on Mars; a planet in much more danger due to its proximity to the asteroid belt.

      February 15, 2013 at 2:52 pm |
  16. Mott

    Probably time to delete this article. Makes the author look like a fool.

    February 15, 2013 at 2:19 pm |
  17. Mary Glance

    Exactly what I thought. The same day the world is surprised with a meteor(which is an asteroid that fell on earth) in Russia, we get an article pretending that asteroids don't surprise us anymore. Good timing Yeomans.

    February 15, 2013 at 1:56 pm |
  18. Men in Black

    Yeomans.... time for your yearly performance review. You missed one (it hit Russia). Time to look for a new job.

    February 15, 2013 at 1:23 pm |


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