• Rock slams into moon, sparks giant explosion

    NASA

    This artist's illustration shows a meteor crashing into the surface of the moon. Scientists say hundreds of space rocks impact the lunar surface every year.

    By Clara Moskowitz
    Space.com

    The moon has a new hole on its surface thanks to a boulder that slammed into it in March, creating the biggest explosion scientists have seen on the moon since they started monitoring it.

    The meteorite crashed on March 17, slamming into the lunar surface at a mind-boggling 56,000 mph (90,000 kph) and creating a new crater 65 feet wide (20 meters). The crash sparked a bright flash of light that would have been visible to anyone looking at the moon at the time with the naked eye, NASA scientists say.

    "On March 17, 2013, an object about the size of a small boulder hit the lunar surface in Mare Imbrium," Bill Cooke of NASA's Meteoroid Environment Office said in a statement. "It exploded in a flash nearly 10 times as bright as anything we've ever seen before." [The Greatest Lunar Crashes Ever]

    NASA astronomers have been monitoring the moon for lunar meteor impacts for the past eight years, and haven't seen anything this powerful before.

    NASA

    This photo shows the bright flash of the light that resulted from a huge boulder slamming into the moon's surface March 17.

    Scientists didn't see the impact occur in real time. It was only when Ron Suggs, an analyst at NASA's Marshall Space Flight Center in Huntsville, Ala., reviewed a video of the bright moon crash recorded by one of the moon monitoring program's 14-inch telescopes that the event was discovered.

    "It jumped right out at me, it was so bright," Suggs said.

    Scientists deduced the rock had been roughly 1-foot-wide (between 0.3 to 0.4 meters) and weighed about 88 pounds (40 kg).The explosion it created was as powerful as 5 tons of TNT, NASA scientists said.

    When researchers looked back at their records from March, they found that the moon meteor might not have been an isolated event.

    "On the night of March 17, NASA and University of Western Ontario all-sky cameras picked up an unusual number of deep-penetrating meteors right here on Earth," Cooke said. "These fireballs were traveling along nearly identical orbits between Earth and the asteroid belt."

    Science(at)NASA

    NASA's lunar monitoring program has detected hundreds of meteoroid impacts. The brightest, detected on March 17, in Mare Imbrium, is marked by the red square.

    Though Earth's atmosphere protected our planet's surface from being hit by these meteors, the moon has no such luck. Its lack of an atmosphere exposes it to all incoming space rocks, and the NASA monitoring program has spotted more than 300 meteor strikes that reached its surface since 2005.

    Part of the motivation for the program is NASA's eventual intent to send astronauts back to the moon. When they arrive, they'll need to know how often meteors impact the surface, and whether certain parts of the year, coinciding with the moon's passage through crowded bits of the solar system, pose special dangers.

    "We'll be keeping an eye out for signs of a repeat performance next year when the Earth-Moon system passes through the same region of space," Cooke said. "Meanwhile, our analysis of the March 17th event continues."

    The scientists also hope to use NASA's Lunar Reconnaissance Orbiter to photograph the impact site to learn more about how the crash occurred. 

    Follow Clara Moskowitz on Twitter and Google+. Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com.

    Copyright 2013 Space.com, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

  • Rock on! Rare 40-pound meteorite found in Antarctica

    International Polar Foundation

    The fifth-largest meteorite ever found in East Antarctica was discovered Jan. 28 by an international team of meteorite hunters. "This is the biggest meteorite (40 pounds) found in East Antarctica for 25 years," one geologist said.

    By Becky Oskin
    LiveScience

    Meteorite hunters at the bottom of the world bagged a rare find this southern summer: a 40-pound (18 kilogram) chunk of extraterrestrial rock.

    A team from Belgium and Japan discovered the hefty meteorite as the members drove across the East Antarctic plateau on snowmobiles. Initial tests show it is an ordinary chondrite, the most common type of meteorite found on Earth, Vinciane Debaille, a geologist from Université Libre de Bruxelles in Belgium, said in a statement.

    "This is the biggest meteorite found in East Antarctica for 25 years," Debaille said. "This is something very exceptional. When you find such a meteorite on Earth, it means that when it was in the sky, it was much larger." [Images of the Antarctic meteorite.]

    The Russian meteor that burst into fragments above the Chelyabinsk region on Feb. 15 is also an ordinary chondrite, according to initial tests by Russian scientists.

    International Polar Foundation

    More than 38,000 meteorites have been found in Antarctica, but only 30 bigger than 40 pounds (18 kg). This big meteorite found in Antarctica is an ordinary chondrite.

    Every year, scientists travel to Antarctica to search for meteorites. Their charred black crust stands out starkly in the white snow, and the cold, dry climate helps preserve any organic chemicals inside the rocks.

    The expedition collected 425 meteorites in 40 days, with a total weight of 165 pounds (75 kg). Debaille said they may have found one Mars meteorite and one piece of the asteroid Vesta among the many discoveries.

    The researchers canvassed the Nansen Ice Field, 86 miles (140 kilometers) south out of the International Polar Foundation's Princess Elisabeth station. The United States also sent scientists out on the polar ice to collect meteorites this season, from McMurdo Station on the opposite end of the continent.

    Reach Becky Oskin at boskin@techmedianetwork.com. Follow her on Twitter @beckyoskin. Follow OurAmazingPlanet on Twitter @OAPlanet. We're also on Facebook and Google+.

    Copyright 2013 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

  • Fireball over N. California causes stir

    Traveling at 33,000 mph, a massive meteor hit the Earth's atmosphere creating a giant shockwave that blew out windows of glass, injuring nearly 1,000 people and creating panic. On the same day, an asteroid half the size of a football field came within 17,000 miles from Earth. NBC's Tom Costello reports.

    By Gil Aegerter, NBC News

    A fireball streaking across the Northern California sky Friday night brought a flood of witness reports -- the same day that a meteor exploded over Russia and an asteroid made a near-Earth fly-by.

    The fireball was seen around 7:45 p.m., by witnesses as far north as Fairfield and as far south as Gilroy, NBCBayArea.com reported. It was also reportedly seen in Sacramento and Walnut Creek. NBC station KSBW of Monterey said the object was visible along California's Central Coast, too.

    NBCBayArea.com said Candice Guruwaiya gave this account on Facebook of seeing it in San Jose: "I was leaving Safeway on Branham and Snell when I saw it. ... It was a bright green when it first appeared, then it went to a bright yellow. It was awesome!"

    The fireball was seen about 24 hours after a meteor exploded over Russia's Chelyabinsk region and a 150-foot-wide asteroid came within 17,200 miles of Earth.

    An astronomer at the Chabot Space and Science Center in Oakland told NBCBayArea.com that Friday night's event wasn't related to the asteroid's passing:

    Gerald McKeegan, an astronomer at Chabot, said he did not see it, but based on accounts he thinks it was a "sporadic meteor," which can happen several times a day but  most of the time happens over the ocean, away from human eyes. Sporadic meteors bring as much as 15,000 tons of space debris to Earth each year, according to McKeegan. He explained that meteors, which are hunks of rock and metal from space that fall to Earth, burn up as they go through Earth's atmosphere, which is what apparently  caused tonight's bright flash of light.

    He said it was likely smaller than another meteor that landed in the Bay Area in October, which caused a loud sonic boom as it fell, breaking apart and spreading rocks, called meteorites, in the North Bay.

    More about the cosmic hits (and near-misses):

    Astrophysicist Neil deGrasse Tyson, director of the Hayden Planetarium, speaks to NBC's Lester Holt about the meteor and asteroid that approached Earth on Friday.