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Astrophysicists Use Apollo Seismic Array To Hunt For Gravitational Waves

Posted by Soulskill on from the where-in-the-moon-is-carmen-sandiego dept.

KentuckyFC writes: Back in the 1970s, the astronauts from Apollos 12, 14, 15, and 16 set up an array of seismometers on the lunar surface to listen for moonquakes. This array sent back data until 1977, when NASA switched it off. Now astrophysicists are using this lunar seismic data in the hunt for gravitational waves. The idea is that gravitational waves must squeeze and stretch the Moon as they pass by and that at certain resonant frequencies, this could trigger the kind of seismic groans that the array ought to have picked up. However, the data shows no evidence of activity at the relevant frequencies.

That's important because it has allowed astronomers to put the strongest limits yet on the strength of gravitational waves in this part of the universe. Earlier this year, the same team used a similar approach with terrestrial seismic data to strengthen the existing limits by 9 orders of magnitude. The lunar data betters this by yet another order of magnitude because there is no noise from sources such as oceans, the atmosphere and plate tectonics. The work shows that good science on gravitational waves can be done without spending the hundreds of millions of dollars for bespoke gravitational wave detectors, such as LIGO, which have yet to find any evidence of the waves either.

10 of 25 comments (clear)

  1. Gravity Waves of Unusual Size? by Mr+Z · · Score: 4, Funny

    I doubt they exist.

    --
    Program Intellivision!
    1. Re:Gravity Waves of Unusual Size? by Steve1952 · · Score: 2

      You mean the G. W. O. U. S's? You keep using that word. I do not think it means what you think it means.

    2. Re:Gravity Waves of Unusual Size? by K.+S.+Kyosuke · · Score: 2

      How I Gravimetrically Deduced The Existence of Your Mother-in-law...? As far as names for TV shows go, one could do even worse.

      --
      Ezekiel 23:20
  2. Gratuitous LIGO Slam by PvtVoid · · Score: 5, Insightful

    The work shows that good science on gravitational waves can be done without spending the hundreds of millions of dollars for bespoke gravitational wave detectors, such as LIGO, which have yet to find any evidence of the waves either.

    Do you mean aside from the cost of putting seismometers on the moon in the first place?

    The experiment referenced is a fabulously clever re-use of existing data, but it has nothing whatsoever to say about the funding case for LIGO. LIGO, like many cutting-edge experiments, requires very long-term technology development before it can produce a positive result. Some science requires long-term thinking, not just until the next quarter or the next election cycle.

    1. Re:Gratuitous LIGO Slam by Idarubicin · · Score: 2

      The experiment referenced is a fabulously clever re-use of existing data, but it has nothing whatsoever to say about the funding case for LIGO. LIGO, like many cutting-edge experiments, requires very long-term technology development before it can produce a positive result. Some science requires long-term thinking, not just until the next quarter or the next election cycle.

      Indeed. One wonders what remarkable scientific discoveries and conclusions will result from creative analysis of today's data, forty years hence.

      ...At least, as long as we actually do continue to fund new instruments and research, and don't insist that all data collection is now 'done', and that all the work that remains is winnowing smaller and smaller pieces of useful information from the last century's scientific output.

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      ~Idarubicin
    2. Re:Gratuitous LIGO Slam by RockDoctor · · Score: 2

      Do you mean aside from the cost of putting seismometers on the moon in the first place?

      The seismographs were a piggy-back on what was essentially a political project.

      Getting unexpected results like this out of data such as a seismograph simply means that any piece of hardware that lands on another planet, moon or comet will have what seismographic equipment put on board that the weight (and/ or data transmission) budget can support without busting anything else. Data links and relays would be additional hardware to put on such jettisoned hardware.

      --
      Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
    3. Re:Gratuitous LIGO Slam by stoatwblr · · Score: 3, Interesting

      "One wonders what remarkable scientific discoveries and conclusions will result from creative analysis of today's data, forty years hence."

      None whatsoever if the data isn't curated.

      One of my constant battles is to get resources to retain data from old space missions. They're flagwaving missions first and scientific expeditions second, which means there's very little interest in keeping record around for prolonged periods.

      That's DESPITE pointing out that if the raw data for NOAA satellites hadn't been kept, it would have been impossible to use them to confirm the existance and development of the ozone hole, simply because the processing system discarded low data values as "equipment error" - which added 20 years to the discovery of the thing in the first place.

  3. Lunar resonance can be quite sensitive. by queazocotal · · Score: 4, Insightful

    But only at specific resonant frequencies.
    LIGO is in principle sensitive to very different frequencies of gravity waves.

  4. Good science, me too! by Lije+Baley · · Score: 2

    My experiments with a laser pointer and a moldy old potato have clearly established that gravitational waves are not strong enough to affect it.

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    Strange things are afoot at the Circle-K.
  5. This was attempted in the 1970s by rotenberry · · Score: 4, Informative

    The idea of using Lunar Seismic activilty to measure gravitational radiation dates back to the 1970s.

    http://en.wikipedia.org/wiki/A...

    In particular, consider the purpose of the Lunar Surface Gravimeter (LSG).