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[Music]

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bright explosion on the moon presented

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by science at nasa

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for the past eight years nasa

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astronomers have been monitoring the

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moon for signs of explosions caused by

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meteoroids hitting the lunar surface

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lunar meteor showers have turned out to

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be more common than anyone expected with

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hundreds of detectable impacts occurring

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every year

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they've just seen the biggest explosion

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in the history of the program

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on march 17 2013 an object about the

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size of a small boulder hit the lunar

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surface in mari imbrium says bill cook

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of nasa's meteoroid environment office

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it exploded in a flash nearly 10 times

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as bright as anything we've ever seen

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before

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anyone looking at the moon at the moment

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of impact could have seen the explosion

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no telescope required

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for about one second the impact site was

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glowing like a fourth magnitude star

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ron suggs an analyst at the marshall

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space flight center was the first to

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notice the impact in a digital video

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recorded by one of the monitoring

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program's 14-inch telescopes

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it jumped right out at me it was so

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bright he recalls

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the 40 kilogram meteoroid measuring 0.3

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to 0.4 meters wide hit the moon

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traveling 56 000 miles per hour the

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resulting explosion packed as much punch

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as five tons of tnt

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cook believes the lunar impact might

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have been part of a much larger event

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on the night of march 17th nasa and

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university of western ontario all sky

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cameras picked up an unusual number of

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deep penetrating meteors right here on

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earth he says

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these fireballs were traveling along

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nearly identical orbits between earth

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and the asteroid belt

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this means earth and the moon were

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pelted by meteoroids at about the same

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time

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my working hypothesis is that the two

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events are related and that this

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constitutes a short duration cluster of

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material encountered by the earth moon

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system says cook

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one of the goals of the lunar monitoring

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program is to identify new streams of

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space debris that pose a potential

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threat to the earth moon system

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the march 17th event seems to be a good

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candidate

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controllers of nasa's lunar

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reconnaissance orbiter have been

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notified of the strike the crater could

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be as wide as 20 meters which would make

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it an easy target for lro the next time

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the spacecraft passes over the impact

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site

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comparing the size of the crater to the

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brightness of the flash would give

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researchers a valuable ground truth

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measurement to validate lunar impact

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models

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unlike earth which has an atmosphere to

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protect it the moon is airless and

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exposed lunar meteors crash into the

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ground with fair frequency

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since the monitoring program began in

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2005 nasa's lunar impact team has

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detected more than 300 strikes

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most orders of magnitude fainter than

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the march 17th event

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statistically speaking more than half of

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all lunar meteors come from known

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meteoroid streams such as the perseids

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and leonids

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the rest are sporadic meteors random

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bits of comet and asteroid debris of

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unknown parentage

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u.s space exploration policy eventually

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calls for extended astronaut stays on

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the lunar surface

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identifying the sources of lunar meteors

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and measuring their impact rates gives

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future lunar explorers an idea of what

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to expect

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is it safe to go on a moonwalk or not

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the middle of march might be a good time

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to stay inside

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we'll be keeping an eye out for signs of

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a repeat performance next year when the

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earth moon system passes through the

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same region of space says cook

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meanwhile our analysis of the march 17th

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event continues

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for updates about explosions on the moon

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and elsewhere in the cosmos stay tuned