Lunar Geminids

Jan 04, 2007
Lunar Geminids
Lunar impacts since Nov. 2005. Numbers 14-16 and 19-20 are Geminids. Number 18 is a probable Geminid. Credit: NASA Meteoroid Environment Group.

Another meteor shower, another bunch of lunar impacts... "On Dec. 14, 2006, we observed at least five Geminid meteors hitting the Moon," reports Bill Cooke of NASA's Meteoroid Environment Office in Huntsville, AL. Each impact caused an explosion ranging in power from 50 to 125 lbs of TNT and a flash of light as bright as a 7th-to-9th magnitude star.

The explosions occurred while Earth and Moon were passing through a cloud of debris following near-Earth asteroid 3200 Phaethon. This happens every year in mid-December and gives rise to the annual Geminid meteor shower: Streaks of light fly across the sky as rocky chips of Phaethon hit Earth's atmosphere. It's a beautiful display.

The same chips hit the Moon, of course, but on the Moon there is no atmosphere to intercept them. Instead, they hit the ground. "We saw about one explosion per hour," says Cooke.

How does a meteoroid explode? "This isn't the kind of explosion we experience on Earth," explains Cooke. The Moon has no oxygen to support fire or combustion, but in this case no oxygen is required: Geminid meteoroids hit the ground traveling 35 km/s (78,000 mph). "At that speed, even a pebble can blast a crater several feet wide," says Cooke. "The flash of light comes from rocks and soil made so hot by impact that they suddenly glow."

Cooke's group has been monitoring the Moon's nightside (the best place to see flashes of light) since late 2005 and so far they've recorded 19 hits: five or six Geminids, three Leonids, one Taurid and a dozen random meteoroids (sporadics). "The amazing thing is," says Cooke, "we’ve done it using a pair of ordinary backyard telescopes, 14-inch, and off-the-shelf CCD cameras. Amateur astronomers could be recording these explosions, too."

Indeed, he hopes they will. The NASA team can't observe 24-7. Daylight, bad weather, equipment malfunctions, vacations—"lots of things get in the way of maximum observing." Amateur astronomers could fill in the gaps. A worldwide network of amateurs, watching the Moon whenever possible, "would increase the number of explosions we catch," he says.

To that end, Cooke plans to release data reduction software developed specifically for amateur and professional astronomers wishing to do this type of work. The software runs on an ordinary PC equipped with a digital video card. "If you have caught a lunar meteor on tape, this program can find it. It eliminates the need to stare at hours of black and white video, looking for split-second flashes."

More data will help NASA assess the meteoroid threat as the agency prepares to send astronauts back to the Moon.

Source: by Dr. Tony Phillips, Science@NASA

Explore further: Bright points in Sun's atmosphere mark patterns deep in its interior

add to favorites email to friend print save as pdf

Related Stories

Building BICEP2: A conversation with Jamie Bock

Mar 18, 2014

Caltech Professor of Physics Jamie Bock and his collaborators announced on March 17, 2014 that they have successfully measured a B-mode polarization signal in the cosmic microwave background (CMB) using the ...

Young stars cooking in the Prawn Nebula

Sep 18, 2013

The glowing jumble of gas clouds visible in this new image make up a huge stellar nursery nicknamed the Prawn Nebula. Taken using the VLT Survey Telescope at ESO's Paranal Observatory in Chile, this may well ...

NASA: Flash reports consistent with single meteor

Mar 23, 2013

(AP)—Reports of a flash of light that streaked across the sky over the U.S. East Coast appeared to be a "single meteor event," the U.S. space agency said. Residents from New York City to Washington and ...

Recommended for you

Astronauts to reveal sobering data on asteroid impacts

18 hours ago

This Earth Day, Tuesday, April 22, three former NASA astronauts will present new evidence that our planet has experienced many more large-scale asteroid impacts over the past decade than previously thought… ...

Rosetta instrument commissioning continues

19 hours ago

We're now in week four of six dedicated to commissioning Rosetta's science instruments after the long hibernation period, with the majority now having completed at least a first initial switch on.

Astronaut salary

19 hours ago

Talk about a high-flying career! Being a government astronaut means you have the chance to go into space and take part in some neat projects—such as going on spacewalks, moving robotic arms and doing science ...

Red moon at night; stargazer's delight

Apr 16, 2014

Monday night's lunar eclipse proved just as delightful as expected to those able to view it. On the East Coast, cloudy skies may have gotten in the way, but at the National Science Foundation's National Optical ...

User comments : 0

More news stories

Cosmologists weigh cosmic filaments and voids

(Phys.org) —Cosmologists have established that much of the stuff of the universe is made of dark matter, a mysterious, invisible substance that can't be directly detected but which exerts a gravitational ...

Hubble image: A cross-section of the universe

An image of a galaxy cluster taken by the NASA/ESA Hubble Space Telescope gives a remarkable cross-section of the Universe, showing objects at different distances and stages in cosmic history. They range ...

Male monkey filmed caring for dying mate (w/ Video)

(Phys.org) —The incident was captured by Dr Bruna Bezerra and colleagues in the Atlantic Forest in the Northeast of Brazil.  Dr Bezerra is a Research Associate at the University of Bristol and a Professor ...