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Space

Big Asteroid (With Its Own Moon) To Have Closest Approach With Earth Today 87

Posted by Soulskill from the everybody-wave dept.
An anonymous reader writes "Asteroid 1998 QE2 has an estimated diameter of 2.7 km. This asteroid will have a close approach with Earth at about 15.2 LD (Lunar Distances = ~384,000 kilometers) or 0.0392 AU (1 AU = ~150 million kilometers) at 2059 UT on 2013 May 31 and it will reach the peak magnitude ~10.8 on May 31 around 2300 UT." Radar images of the asteroid taken Wednesday show that 1998 QE2 has its own tiny moon, about 600 meters wide. Phil Plait explained how the images were taken, and what further information we gleaned from them. 'The very presence of the moon is a good thing. By measuring how long it takes to go around the primary, the mass of the primary can be found using math known for centuries (the more massive the big asteroid, the faster the moon will go around it at a given distance). We also know the size of the primary, so that means we can find its density, and therefore what it’s made of (probably mostly rock).'
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Big Asteroid (With Its Own Moon) To Have Closest Approach With Earth Today More

Big Asteroid (With Its Own Moon) To Have Closest Approach With Earth Today

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  • Thats no moon... (Score:4, Funny)

    by Anonymous Coward on Friday May 31, 2013 @01:59PM (#43876247)

    It's a space station!

  • So I put an asteroid on your asteroid, so you can watch a flyby while you're watchin' a flyby!

  • Well (Score:5, Funny)

    by Antipater ( 2053064 ) on Friday May 31, 2013 @02:03PM (#43876299)

    (probably mostly rock).

    At least it's not some kind of smooth alternative. But I was hoping for something heavier, maybe with metal influences.

  • ... that the tidal gravitational wave of Earth/Moon will disrupt the small couple?

    • ... that the tidal gravitational wave of Earth/Moon will disrupt the small couple?

      Shut it... You just gave Michael Bay a terrible idea for a disaster movie.

    • Re:Any luck... (Score:4, Insightful)

      by cusco ( 717999 ) <brian DOT bixby AT gmail DOT com> on Friday May 31, 2013 @02:28PM (#43876661)
      No, not much chance of that. Gravity, like other forms of energy, falls off according to the inverse square rule. If object B is twice as far away as object A it is only attracted at 1/4 (1/2^2) the force. Object C is five times further away as Object A, only gets attracted 1/25th as much (1/5^2). These are far enough away that their mutual gravity is a much stronger force than that of the Earth/Moon system, so our gravity applies effectively equal force on both objects. Clear as mud?

      • Re: (Score:1)

        by Arkh89 ( 2870391 )
        Nope that's clear. Although, I wouldn't expect it to crash on my house but rather I should re-phrase : is it possible to see a change in the elliptic trajectory while it is passing next to us?
      • Well, you really need to replace "force" with "acceleration" in your explanation. Because if "our gravity applies effectively equal force on both objects", then the smaller object is going to accelerate away from the larger object quite nicely...

        • Re: (Score:1)

          by cusco ( 717999 )
          Yup, was distracted and couldn't think of the right word. Figured someone would correct me eventually :-)

  • Intellible units... (Score:4, Informative)

    by taiwanjohn ( 103839 ) on Friday May 31, 2013 @02:28PM (#43876659)

    15.2 LD (Lunar Distances = ~384,000 kilometers) or 0.0392 AU (1 AU = ~150 million kilometers)

    Or maybe we could just say "around four million miles" and be done with it. Add in the metric conversion if you want, but really, do we need an explication of "AU" and "LD" for this story? Just convert it to human readable format. It's one of those things that "journalists" do...

    • Re: (Score:1)

      by nielsm ( 1616577 )

      On the other hand, the comparison to the Moon's distance is useful. "It's more than 15 times further away than the moon" gives a good point of comparison. It certainly makes it clearer to me that there's no risk it will hit anything we should care about.

      • I agree, but I would have said "Around four million miles (roughly 15 times as far as the moon)".

        I'm "geeky" enough to know that one "LD" is about a quarter-million miles, but most people don't know that. And even I don't want to get the info in those units. It's just awkward.

        PS: BTW, I seem to be missing a "gi" in my subject line... I meant to say "intelligible", not intellible. ;-)

    • Re:Intellible units... (Score:4, Insightful)

      by gmuslera ( 3436 ) on Friday May 31, 2013 @03:11PM (#43877251) Homepage Journal
      Scientific units are basically metric, those are the intellible units, not the arbitrary cultural ones that are used just for 3 or 4 countries in all the world. And putting the distance in lunar distances (or, maybe, Earth diameters that are around 12000km) puts in the right perspective how far they will be and how little we should worry about them, at least this pass (should you worry about a collision if a grain of sand passes 1km away from you at the closest point?)

    • Re: (Score:2)

      by invid ( 163714 )
      AU is fairly common when discussing distances within a solar system. If you play Eve Online it is a unit of measure you are familiar with. If the asteroid was tree shaped it would be really familiar to an Eve player.

      • I'm quite familiar with the "AU" unit. But it's not a very useful measure to most folks when the value is 0.0392. Might as well measure it in rods or furlongs or cubits...

      • I was expecting to find that the item orbiting the asteroid would be tree shaped perhaps. That would be a great find :)

        I want my Archon :)

    • For people who don't already know those things off the top of their heads, it gives them a sense of scale.

  • During the last asteroid flyby there was a coincidental meteor explosion in the former Soviet Union, caught by hundreds of in-car dash cameras... SAME DAY...

    So, I would assume that this flyby should also have an associated and completely unexpected rock from space approaching from the opposite direction and oh, I dunno, wipe out Paris?

    I mean, destruction of a major city from space would be horrific and all, but I can't imagine anything joining the world together in unity to create a real space defense (and

    • I can't imagine anything joining the world together in unity to create a real space defense (and get us out there and off this rock) than a few million people getting killed at once.

      You missed the memo. It was in the We The Geeks NASA G+ hangout today. Some folks actually care about the issue enough to put their money and time where their mouth is and thus are actually doing what you propose. [youtube.com]

      • Re: (Score:2)

        by stjobe ( 78285 )

        You missed the memo. It was in the We The Geeks NASA G+ hangout today. Some folks actually care about the issue enough to put their money and time where their mouth is and thus are actually doing what you propose. [youtube.com]

        Thank you for that link!

        That Hangout was surprisingly informative, and the panel was excellent; not a dud in there:
        Lori Garver, Deputy Administrator, NASA
        Bill Nye, Executive Director, Planetary Society
        Ed Lu, former astronaut and CEO, B612 Foundation
        Peter Diamandis, Co-Founder and Co-Chairman, Planetary Resources
        Jose Luis Galache, Astronomer at the International Astronomical Union’s Minor Planet Center

  • Ouch (Score:2)

    by quax ( 19371 )

    That's one mofo of a planet killer sized asteroid.

    • not really, it would "kill the humans" but not all life. Earth took a 10km asteroid back in the day 65 million years ago and it caused mass extinctions, but still not complete obliteration of the biosphere.

      • Re: (Score:2)

        by quax ( 19371 )

        Yeah, I am just anthropocentric like that.

        • good news for you then, some humans are predicted to survive an impact even of asteroids twice the diameter of this article's one though most would die. Taking a philosophical view, something would "evolute" to take man's place even if all humans wiped out, so why not just care as much about the next kind of people as human ones? I don't see any reason to care more about future humans I''ll never meet as some other kind of people-creature.

          • Re: (Score:2)

            by quax ( 19371 )

            You must not have kids.

            • yes I do

              so your telling me you deeply care about your great-great-(twenty times) grandchildren? bullshit. you'll never know them, they're total strangers.

              • Re: (Score:2)

                by quax ( 19371 )

                You only care about people you know personally?

              • Re: (Score:2)

                by booch ( 4157 )

                so your telling me you deeply care about your great-great-(twenty times) grandchildren?

                Of course I care about them. Why else would I need my copyright to last so long?

  • Oh my God, I want one (Score:3)

    by __aaltlg1547 ( 2541114 ) on Saturday June 01, 2013 @07:58AM (#43882245)
    How cool is this. 1.7 miles of orbiting rock. Let's capture that sucker and bring it where we can use it.

  • I'm guessing the "moon" is called Philip?

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