Lunar gravity-maps

Joly sez,

These print-resolution stills were created for the cover of the February 8, 2013 issue of Science. They show the free-air gravity map developed by the Gravity Recovery and Interior Laboratory (GRAIL) mission.

If the Moon were a perfectly smooth sphere of uniform density, the gravity map would be a single, featureless color, indicating that the force of gravity at a given elevation was the same everywhere. But like other rocky bodies in the solar system, including Earth, the Moon has both a bumpy surface and a lumpy interior. Spacecraft in orbit around the Moon experience slight variations in gravity caused by both of these irregularities.

The free-air gravity map shows deviations from the mean, the gravity that a cueball Moon would have. The deviations are measured in milliGals, a unit of acceleration. On the map, dark purple is at the low end of the range, at around -400 mGals, and red is at the high end near +400 mGals. Yellow denotes the mean.

These views show a part of the Moon's surface that's never visible from Earth.

GRAIL Free-Air Gravity Map for the Cover of Science


  1. While this is interesting I’d like to know what sort of use this will be. I’m sure it could be I just can’t think of it.

    1.  The variations are so pronounced that they make low Lunar orbits unstable. This data could be useful if you want to put something in Lunar orbit.

    2. They are useful for understanding the subsurface structure, physical processes and history of the moon. The moon and earth are related in many respects (e.g. where we are in the solar system), but the moon tends to preserve structure that is obliterated by fast weathering and plate tectonics. So the maps are also related to earth’s history.

  2. If you’re a geologist gravity anomalies are incredibly useful for giving some indication of the internal structure of a body. The physical size, rate of change and magnitude of gravitational anomalies let you begin to map where material of greater or lesser density is located inside the body – is it a shallow magmatic intrusion, is it molten or partially molten, is it something deep down and so on…
    There’s a pronounced asymmetry in the appearance of the Moon between front-side and far-side with far more large infilled impact basins on the side closest to Earth. These are associated with similar differences between the gravitational patterns of the two hemispheres.

    1.  мy coυѕιɴ ιѕ мαĸιɴɢ $51/нoυr oɴlιɴe. υɴeмployed ғor α coυple oғ yeαrѕ αɴd prevιoυѕ yeαr ѕнe ɢoт α $1З619cнecĸ wιтн oɴlιɴe joв ғor α coυple oғ dαyѕ. ѕee мore αт…­ ­ViewMore——————————————&#46qr&#46net/kkEj

      variations are so pronounced that they make low Lunar orbits unstable.
      This data could be useful if you want to put something in Lunar orbit.

  3. erm….I thought gravity was based purely on the mass of the body…physics is so weird.

  4. Once and for all!!
    Incontrovertible proof that the moon isn’t just grey.
    The moon landings were faked!

Comments are closed.