2012 DA14 Sparks Asteroid Fever Plus Vesta In 3-D

Illustration of an asteroid and its tiny moon making a close pass by Earth. Credit: ESA

Here we go again. Heard of the latest asteroid to strike terror across the Web? It’s 2012 DA14, a flying rock almost 150 feet across discovered on February 23 by astronomers at Observatorio Astronomico de La Sagra in Spain. The observatory uses robotic telescopes to find and track near-Earth asteroids. At the time of discovery, DA14 was passing Earth at a fairly typical distance of 1.5 million miles.

After calculating a preliminary orbit for 2012 DA14, astronomers learned that on February 15, 2013, it will zoom by only 17,000 miles from the surface of our planet. While this is very close by solar system standards, it’s a long ways for you and I. If you consider that the diameter of Earth is about 8,000 miles, this small object will miss us by more than twice that. While it will very briefly pass through the geosynchronous satellite belt, the odds of it hitting one are extremely small. The average separation between satellites there is 59 miles. A geosynchronous satellite orbits 22, 236 miles above Earth, an altitude where the satellite’s orbital period matches Earth’s rotation. That means they’re essentially stationary in the sky, making them ideal for relaying communications around the globe. But I digress.

Most asteroids reside in the main belt beyond Mars, but there are additional asteroid families - the Apollos and Atens - whose orbits cross that of Earth's and have the potential to impact in the future. Mars orbit crossers are called Amors. Credit: ESA / Medialab

Some websites are saying a strike is imminent or at the very least possible. The fact is, it won’t happen in the foreseeable future. Yes, it’s possible that sometime in the distant future, there might be a closer pass or even a dead-on hit, but that’s not in the cards for now. On the Torino Impact Hazard Scale DA14 rates a “0”, defined as:

The likelihood of a collision is zero, or is so low as to be effectively zero. Also applies to small objects such as meteors and bodies that burn up in the atmosphere as well as infrequent meteorite falls that rarely cause damage.

And on the related Palermo Impact Scale, it comes in at a -4 , meaning there will be no consequences during this flyby. You might recall the hype surrounding the even closer flyby of asteroid 2011 MD last June. That asteroid, which measured between 3o and 150 feet across, came even closer than DA14 will at a distance of only 7,500 miles. We all survived.

2011 MD passed so near Earth last June our planet's gravity significantly changed the tip or inclination of its orbit. We're the gravity hog compared to these small objects. Credit: NASA

Ongoing surveys like the one at La Sagra are underway to find every possible rock big enough to put the hurt on Earth. Most of the asteroids measuring one kilometer or more have been seen and their orbits determined, but there are still plenty of extremely faint and small rocks out there like DA14. Expect many more to be found in the coming years.

Since we’re talking asteroids, let’s head out to the main belt to Vesta and see what the Dawn space probe’s been up to lately.

This 3-D photo shows the central complex in Vesta’s Rheasilvia impact basin. The central complex is approximately 120 miles in diameter and has about 12 miles of relief from its base, making it about two and a half times taller than Mt. Everest. Click to enlarge. Credit: all photos NASA/ JPL-Caltech/ UCLA/ MPS/ DLR/ IDA

NASA’s Jet Propulsion Lab has released several excellent 3D images recently that give you that “being there” feeling. To see depth in the photos, you’ll need a pair of those red-blue specs called 3-D anaglyph glasses. Click HERE to order a free pair.

Caparronia crater is the large, roughly 18 mile diameter crater in the top part of the image. The 3D effect highlights the large ridge running across the base of the crater. Also visible is the large, degraded crater offset from the center of the image. Click to enlarge.

In addition to creating detailed photographic maps from its 130-mile-high orbit, Dawn’s been looking for water ice in the asteroid’s polar regions. While none has been discovered yet, the temperature there is colder than -200 F, the cutoff for water to exist in the top 10 feet of Vesta’s rocky soil. The “warmer” equatorial regions hovers around -190 F.

Vesta's equatorial troughs are visible around Vesta’s equator. These troughs encircle most of the asteroid and are up to 12 miles wide. To the north of these troughs are a number of old, highly eroded, large craters.

28 Responses

  1. Sandra Wolff

    Bob, you have a cool hobby! Much more pertinent than boring “Super Tuesday”coverage!!!!!!!

    1. astrobob

      Hi Sandra,
      I hope you enjoy the hobby as well. So many people I know, if they have any interest in science at all, are fascinated by the cosmos and astronomy.

  2. Kathi in MN

    Thanks for the facts! My guy sent me to Google after seeing a report on NBC Nightly News. It was nice to see some facts about this asteroid. I was able to fill him in on the details that NBC failed to give us.

  3. Lynn

    Hi Bob

    True what you said “here we go again”, that’s why I never read about asteroids on the web anymore I just stick to sites that are trustworthy and honest, just like your’s, jpl and nasa. I don’t understand why everyone is getting uptight about this one as its a zero on the torina scale, I used to panic a while ago but now I just wait until their orbits are succesfully sorted out now, rather than jump in when its just been found. Thanks for your true and honest facts that amaze me every night I read them. 🙂

    1. astrobob

      Thanks Lynn. While the recent asteroids will make close passes, it’s not like this hasn’t happened before. I’m still amazed we can track such tiny objects. Makes me feel safer really.

  4. Lynn

    That’s so true Bob, what I say is the more they find the more we know. Is it possible that they will ever be able to find all the NEO or can one just pop up anytime.

    1. astrobob

      I doubt all will be found for two reasons: there are many very small ones that are extremely faint and new ones are being perturbed from the asteroid belt that will eventually come our way.

  5. Kathy from WI

    Thanks for the current info, I just heard about the asteroid this morning at my coffee klutch! Decided to check things out on your web site. I’m hoping for clear skies so I can look for Northern Lights! I find anything about the evening/night skies facinating and love to sit out during the summer months to look for shooting stars etc. Sooooooo interesting.

    1. astrobob

      Hi Kathy,
      And I hope you have clear skies! We’re under clouds here in Duluth. Doesn’t look too good. Let us know what you see. Thanks!

  6. les

    Uh ohhhh….not again…u may need to walk me thru this one bob….please keep me posted on everyhing….
    thank u

  7. Evie

    Why does no one mention the distance of 0.0008 AU on Feb 16, 2013? Why doesn’t the AU to miles calculator come up with 17,000 miles on Feb 15, 2013? It calculates 0.0035 AU as approx. 325,000 miles, not 17,000 miles.

      1. astrobob

        Yes, that’s the one that will pass 17,000 miles away or 0.000181 A.U. from Earth. I’ve seen another larger distance posted because the asteroid’s orbit wasn’t precisely known at the time. I’m confused about your reference to a distance calculator. 0.0035 A.U. equals 325,000 miles. That part is correct.

    1. astrobob

      Not sure what A.U. to miles calculator you’re referring to, but the asteroid will pass 17,000 miles from Earth.

      1. Evie

        Thank you for taking the time to respond to my question.

        There are AU to Miles (or kilometers, etc) converters all over the internet. I wanted to see the 17,000 miles for myself. So I plugged in the AU figure from Nasa’s JPL site. On Feb 15, 2013, they show it as 0.0035 AU. So I plugged that in and I don’t get 17,000 miles. I know I am not a scientist, but that should be straightforward. The converter shows 0.0035 AU as 325345.3254359 miles.

        Thanks again. I love your website!

        1. Evie

          I see you are using the AU from the Close Approach Data graph on JPL. I was using the AU from the Orbit Diagram. My mistake.

  8. Aloha AstroBob!

    Something tells me that many viewers of this site may thing this is a silly/stupid question, however, that’s never stopped me from asking before so why stop now? Heh…

    As close as DA14 is coming to Earth and even though one relatively recently came even closer, something that always bothers me is this: How close does an asteroid the size of DA14 have to come to Earth in order to be pulled in by its gravitational force?

    I know the size of the asteroid and probably the speed has to be taken in to consideration along with the “nearness” of its flyby. That is obvious. Is there a “standard” type of algebraic formula one can use to figure if an asteroid is actually going to make an impact with Earth? That would be great if there were, but something tells me it is much too complicated for a “simple” calculation method so the “common” human could figure it out for themselves. If there were, it could/would keep the masses from ever panicking, agree?

    Thanks for any help or suggestions!

    1. astrobob

      Hi Wayne,
      Very good question. Asteroids strike Earth all the time and end up as meteorites. Most of them get here because either the Earth or the asteroid plow into one other. As you wrote, everything depends on size, closeness of approach and especially speed and angle of entry. Asteroids can get very close to Earth’s surface and still return to space. The Great Daylight Fireball of 1972 (http://en.wikipedia.org/wiki/Great_Daylight_1972_Fireball) measured about 10 feet across and skimmed the atmosphere just 35 miles high before heading back into space. That’s incredibly close, and yet it was never “pulled in” because of its high velocity. If it had entered at a steeper pitch, it would have easily made it through even if it was traveling at a faster speed. I wish I knew of a formula but I’ve not run across one. Maybe other readers can help here.

      1. Wayne Hawk

        I had a feeling since there were so many “factors” in an equation to figure ‘earth-asteroid’ or ‘asteroid-earth’ collisions there wouldn’t be any such thing. In a way, that’s too bad since having one that many folks could use easily would put many a “worry-worts” mind (like mine) at ease without having to bother people such as yourself.

        However, had I not had this concern a few months ago, I’d never have discovered YOUR website. So it has its positive side also. I’ve found your site to be one of the most honest and down to earth (no pun intended) sites regarding answers to questions from the novices regarding all things “space”.

        Thank you for replying. You’re a wonderful person.


        1. astrobob

          Thanks for such high praise Wayne. I try to be straightforward about answering questions. It’s my hope I’m presenting at least a basic understanding of the facts.

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