Researchers working for NASA's Lunar Reconnaissance Orbiter mission have discovered that the Earth's magnetic tail could be harmful to future astronauts. The moon stays inside Earth's 'magnetotail' for six days every month -- during full moon. This can have consequences ranging from lunar 'dust storms' to strong electrostatic discharges, according to one researcher quoted by NASA in 'The Moon and the Magnetotail.' So far, this is pure speculation: no man has been on the moon when the magnetotail hits. As added the same scientist, 'Apollo astronauts never landed on a full moon and they never experienced the magnetotail.' But read more...
As the illustration above shows, "the moon spends about six days each month inside Earth's magnetic tail, or 'magnetotail.'" Credit: NASA/Steele Hill) Here is a link to a larger version of this image.
And here is a link to images of Earth's 'magnetospheric substorms' which could affect future astronauts on the moon. From this page, you'll be able to see a short animation (49 seconds) in various formats. "This animation shows a magnetospheric substorm, during which the reconnection causes energy to be rapidly released along the field lines causing the auroras to brighten." (Credit: Walt Feimer, for NASA/Goddard Space Flight Center, Conceptual Image Lab)
This research work has been led by Tim Stubbs, a University of Maryland scientist working at the Goddard Space Flight Center. For more information, take a look at this University of Maryland, Baltimore County news release, "UMBC Scientist Joins NASA Mission" (April 15, 2008).
Another researcher involved in this project is Jasper Halekas of the University of California, Berkeley, who works in the Space Physics Research Group. Here is a link to his publications. Please note that the link to his home page is not working: it redirects you to his research group.
Now, let's see what could happen monthly on the moon according to NASA. "Imagine what it feels like to be a sock pulled crackling from a dryer. Astronauts on the moon during a magnetotail crossing might be able to tell you. Walking across the dusty charged-up lunar terrain, the astronauts themselves would gather a load of excess charge. Touching another astronaut, a doorknob, a piece of sensitive electronics -- any of these simple actions could produce an unwelcome discharge. 'Proper grounding is strongly recommended,' says Stubbs."
The NASA's writer continues. "The ground, meanwhile, might leap into the sky. There’s growing evidence that fine particles of moondust might actually float, ejected from the lunar surface by electrostatic repulsion. This could create a temporary nighttime atmosphere of dust ready to blacken spacesuits, clog machinery, scratch faceplates (moondust is very abrasive) and generally make life difficult for astronauts."
Here is the conclusion of the NASA's article. "What happens then? Next-generation astronauts are going to find out. NASA is returning to the moon in the decades ahead and plans to establish an outpost for long-term lunar exploration. It turns out they’ll be exploring the magnetotail, too."
Finally, if you want to read more about what might happen to future astronauts on the Moon, you can read "Strange Things Happen at Full Moon" (SPACE.com, April 18, 2008).
Sources: Tony Phillips, NASA's Goddard Space Flight Center, April 16, 2008; and various websites
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