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Small Asteroid To Buzz Earth

Posted by kdawson on from the just-a-flesh-wound dept.

ddelmonte writes in to tell us about a small near-earth object, discovered just 2 days ago, that is expected to pass within 64,000 km of our planet on March 2, 13:44 UT. NEO 2009 DD45 will be well inside the Moon's orbit and just under twice the altitude of geosynchronous satellites. According to Sky and Telescope, 2009 DD45's closest approach will be over the Pacific west of Tahiti, so observers in Australia, Japan, and perhaps Hawaii will have the best chance of spotting it with, say, an 8-in. telescope. Here's where you can generate an ephemeris of the object for your location. At closest approach NEO 2009 DD45 will be moving half a degree per minute and peaking around magnitude 10.5. It will be brighter than 13th magnitude for only a few hours.

11 of 171 comments (clear)

  1. Piggy ride! by Chicken_Kickers · · Score: 5, Interesting

    Why can't we send a probe that will land on this asteroid and then piggy ride on it. That way we don't need more fuel to carry it round the solar system. If the asteroid doesn't go where we want, then have a relaunch mechanism for the probe to get off at the most suitable point in the asteroid's orbit.

    1. Re:Piggy ride! by pcolaman · · Score: 3, Interesting

      I vote we shoot it down, just to see if we can do it. That would be more fun, anyways. I nominate myself to push the button.

    2. Re:Piggy ride! by radtea · · Score: 2, Interesting

      Gigantic. Bungee.

      This is actually not completely insane. Just dumping some guesses at "reasonable" parameters into a dumb-as-rocks bit of Python to simulate the encounter, a bungee with a relaxed length of 1000 km and a spring constant of 10^-3 N/m would do the job with a peak acceleration of about 160 g assuming 50 km/s delta-v. Total acceleration time is about 100 seconds, and the bungee stretches out to about two and a half times its relaxed length.

      If you had a material that would stretch up to 10 times its relaxed length you could keep the peak acceleration down to about 25 g!

      These calculations assume the asteroid is much more massive than the probe--if it is not then the numbers actually get a bit better, as the asteroid slows down a bit as the probe accelerates.

      In any case, I wouldn't rule this out. Hardened instruments can take insanely high accelerations, and materials are getting more incredible all the time.

      --
      Blasphemy is a human right. Blasphemophobia kills.
    3. Re:Piggy ride! by CrimsonAvenger · · Score: 2, Interesting

      With a thirty metre object you could almost snare it with a net. Then you would need a shock absorbing tether to match velocities.

      It's a 30 metre object moving well over escape velocity. You snag it with the net, and then endure 9000 gravities acceleration, and in only a tenth of a second, you've matched orbits.

      If your tether will stretch to a length of 450 metres while holding a weight (you, or a satellite your size) of about 2000 tons.

      Good luck with that.

      Given that materials for tethers are improving all the time, and that high tech space drives are not inventing themselves the way they do on star trek, I wonder if this could be a practical way to travel around the inner solar system

      In a word, no. If you want more words, "practical" doesn't begin to describe this notion.

      --

      "I do not agree with what you say, but I will defend to the death your right to say it"
    4. Re:Piggy ride! by retchdog · · Score: 2, Interesting

      It's not crazy at all: http://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion)

      Compared to using pneumatic springs to harness and dampen the force of exploding atomic bombs in order to propel a manned craft, coupling to an asteroid is downright quaint.

      --
      "They were pure niggers." – Noam Chomsky
  2. Re:Another perspective by MichaelSmith · · Score: 2, Interesting

    In those few hours it will be greater than 13th magnitude it's velocity will change by about 1km/s or ~30000km/h from the force of the earth alone.

    Most of which it will give back on the way out. So what is the net velocity change for the earth encounter?

    --
    http://michaelsmith.id.au
  3. A potential 3rd moon? by pecosdave · · Score: 2, Interesting

    Assuming of course you count Cruithne as a moon. What happens once it passes our gravity?

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  4. Re:Impossible in this timespan by Nyeerrmm · · Score: 4, Interesting

    While you're absolutely correct, there is a program known as Operationally Responsive Space (ORS) thats being headed up by DoD rather than NASA that is headed in that direction. I think the time-frame they're considering is closer to 2 weeks, but the general idea is to be able to recognize a need, and design, construct and launch a mission in that period of time. That includes getting adjustable plug-and-play parts (GNC, Power, structures, propulsion) that you can tune and modify quickly to fit the mission profile.

    Presumably, a lot of the work to streamline the process of designing the bus and plugging in instruments could be easily translated to space science missions, and if a future opportunity like this were available we could do exactly that. Of course, you'd have to have a pretty interesting guidance system and a very robust structure, since you'd only get an advantage if you stuck the probe in the asteroids path and let it slam into it to get the momentum.

  5. Close call by mc1138 · · Score: 4, Interesting

    While right now 64,000 puts it fairly far out in terms of all the junk orbiting the earth, it is significantly closer than the moon is. Even if it still missed the earth, just a few thousand kilometers closer and it could reek havoc on all the man-made junk spinning around the Earth. How much potential damage/debris could that cause?

    --
    The musings of just another geek and his junk.
  6. What if it waits in orbit? by Mathinker · · Score: 2, Interesting

    If you had several such pre-built probes waiting in orbit, you would have a much better chance, no? The probes would have the advantage that they're already out of the deepest part of Earth's gravity well, and that you could choose the one whose orbit is best. I would think that with only two or three you would be able to do what he wanted.

    OTOH, I'm not convinced it would be cost-effective. Depends on how often do asteroids pass by close enough to make it worth our while (and how often they're worth piggy-backing upon), versus the cost saved for getting where you want to go.

  7. Re:Impossible in this timespan by idigitallDotCom · · Score: 2, Interesting

    THREE days?????? surely the space agencies had some inkling about this asteroid much longer before now? Surely they do some sort of skywatch/asteroid/meteor monitoring. What's so special about this asteroid that noone knew it was coming around here and how big/fast it is? I'd be seriously worried if 3 days was their minimum time to interception.

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    blog.idigitall.com