Dusty Space Around the Moon

6 Responses to Dusty Space Around the Moon

1. LocalFluff says:

   June 19, 2015 at 3:55 am

   Could it matter where on the Moon Apollo 17 saw the sun set? Over a local lunar magnetic field, or the angle to Earth, or to its magnetic tail, for example. As a potential hint to an explanation for the one-off observation thus far.
   • Paul Spudis says:

     June 19, 2015 at 4:21 am

     Perhaps. But magnetic anomalies (strong ones) are rare on the Moon and mostly at non-equatorial latitudes (all of the Apollo flights were in low inclination orbits).
2. J Fincannon says:

   June 19, 2015 at 9:41 am

   A few things that have bothered me about possible lunar lofted dust.

   One is the boulder tracks and retroreflectors. It seems that both should have been covered by dust if the amount lofted is appreciable. For boulder tracks, they “should” have happened long time ago (>20Myr). Track erosion has been estimated at 2-8 cm/million years, but this excludes dust, although that seems a part of the estimate they did not mention in the analysis. If dust contributed 100% to the erosion, this suggests a tiny amount of dust in the space around the Moon at any specific time. Also, the retroreflectors still seem to work for both Apollo and Lunokhod. I would have thought the dust would cover them too so the dust must be very very sparse.

   Second, how does the “transient lunar phenomena” enter into the picture? Are TLPs geysers of volatiles/dust ejected into lunar space?

   Finally, anomalies in the various laser altimeter experiments. It seems that there have been a number of erroneous data points in the data sets. This includes the Apollo data and LRO data (I have not examined Kaguya in detail). I can see how the Apollo data would be somewhat flaky due to the laser being a new device. LRO is a little different. Could LRO’s LOLA possibly detect this dusty environment? The scientists state that they never expected any returns from dust, only a weaker signal return and it’s not clear if LOLA is affected by the dust. But it would be interesting to try to correlate the “spurious” signals when LOLA has bounced a signal off the surface as it passes the terminator. A nice graduate student activity. I know if you take a low power laser and shine it into the air, the dust is highly illuminated.
   • Paul Spudis says:

     June 19, 2015 at 11:34 am

     The new LADEE estimates suggest that the dust exosphere is of much lower density than had been suggested by the Apollo data, about 2 orders of magnitude less. Thus, it is not surprising that it does not affect LOLA or that surfaces seem to remain largely dust-free. I was thinking more about the Apollo 17 orbital observations and sketches, which are still unexplained.

     As for TLP, dust emissions could possibly explain some of them (i.e., impact ejecta), but the slowly moving lights and glows that make up the classic TLP phenomena seem to be very “un-dustlike.” I suspect many of them to be observer effects (e.g., lens flare) although gas emissions from the interior are certainly possible.
3. Michael Wright says:

   June 19, 2015 at 2:05 pm

   I was intrigued when Brian Day of Ames Research Center said the exosphere of the Moon could be visible to the naked eye if the reflected surface of Moon was not so bright. This article reminded me that LADEE is one of very few discussions about the Moon. Prior to LADEE flight he gave presentations for various groups, this is one of them:
   http://hamradio.arc.nasa.gov/meetings/LADEEpresentation.html
   This exosphere is quite interesting and good to know LADEE helped expand knowledge of this, at dirt cheap costs too.
4. billgamesh says:

   June 19, 2015 at 5:25 pm

   “-although gas emissions from the interior are certainly possible.”

   Gas emissions from Lunite civilization? The aliens that created us millions of years ago? I read the Nazi underground base in Antarctica has been in communication with them and the dust is actually being used as a type of mind control antennae through which their minions are preparing to take over our civilization.

   Kidding aside, I am wondering what kind of useful application this phenomenon could have. I know that terrestrial communication is possible by bouncing signals using meteorite trails. I wonder if heating up this cloud with microwaves or applying some form of magnetic field might be useful in some way. Perhaps there is even a way to harvest energy from these particles.

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