Fireball Over California Exploded with Force of 5 Kilotons

by Nancy Atkinson on April 24, 2012

Want to stay on top of all the space news? Follow @universetoday on Twitter

Location of daylight (8 AM) fireball over California on April 22, 2012. Credit: NASA's Meteor Watch

A daytime fireball over the skies of central/northern California on Sunday morning, April 22, 2012 caused a loud explosion and the event was also detected on several seismographs stations in the area. According to Bill Cooke, head of NASA’s Meteoroid Environments Office, the source of the blast was a meteoroid about the size of a minivan, weighing in at around 70 metric tons (154,300 pounds) and at the time of disintegration released energy equivalent to a 5-kiloton explosion.

For comparison, conventional bombs yield energy from less than 1 ton to 44 tons, and the approximate energy released when the Chicxulub impact caused the mass extinction 65 million years ago was estimated to be equal to 96 million megatons of TNT.

“This was a BIG event,” said Elizabeth Silber of the Meteor Group at the Western University in Ontario, Canada.

“Most meteors you see in the night’s sky are the size of tiny stones or even grains of sand and their trail lasts all of a second or two,” said Don Yeomans of NASA’s Near-Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, Calif. “Fireballs you can see relatively easily in the daytime and are many times that size – anywhere from a baseball-sized object to something as big as a minivan.”

Silber estimates the location of its explosion in the upper atmosphere above California’s Central Valley. It is not known yet if any pieces of the space rock survived to land as meteorites, but the entire object was likely vaporized before hitting the ground. However, you can bet there are people out looking. (Silber said on the Meteorobs newsgroup that based on infrasonic data the approximate source coordinates are 37.6N, 120.5W).

Descriptions of the fireball range from a “silver flash” to like a “green glittering sparkler,” and one person said their sighting of the object was followed 4-5 minutes later by a loud sonic boom.

Unfortunately, since the huge fireball occurred during the day, all of NASA’s meteor-seeking cameras were turned off, so images of the event are sparse. You can see some at news station KTVN’s website.

This type of fireball is quite rare, and visual observations of them are even more rare. “An event of this size might happen about once a year,” said Yeomans. “But most of them occur over the ocean or an uninhabited area, so getting to see one is something special.”

That the fireball occurred during the Lyrid meteor shower is probably a coincidence, most experts are saying, as meteor shower meteors are generally small bits space dust that don’t produce large fireballs. However, another large fireball also occurred on April 20 in Brazil. See more information about that bolide here.

About 

Nancy Atkinson is Universe Today's Senior Editor. She also is the host of the NASA Lunar Science Institute podcast and works with Astronomy Cast. Nancy is also a NASA/JPL Solar System Ambassador.

Paul Shannon April 24, 2012 at 7:24 PM

‘University of Western Ontario’ not ‘Western University of Canada, Ontario’

Martin Lefebvre April 24, 2012 at 8:16 PM

The University Senate changed the name last winter. Most of us still studying there still call it by its old name.

Paul Shannon May 7, 2012 at 7:17 PM

Huh.

zoobygamez April 24, 2012 at 9:10 PM

Thanx for sharing all these wonderful Posts and Blog.I really like them and looking forward for the newposts.You can download Trackmania 2 Canyon, Supreme Commander 2, The Darkness II  From zoobygamez.

Aqua4U April 25, 2012 at 3:01 PM

I wonder what track it took? Is this known by anybody’s radar reflectivity images?

Something moving that fast and exploding that high up might have sprinkled chunks just about anywhere in the direction of travel – IF any pieces survived the breakup. Remember that when the shuttle Columbia broke up over Calif. pieces fell as far away as Texas!

Aqua4U April 25, 2012 at 8:55 PM

So far, the only observed track has it traveling east to west across California… Not much detail in that! One of the observations was from Reno. Whatever that means? Clear sky toward the south?

Omni Software Inc. April 25, 2012 at 4:15 PM

“We don’t have any videos of this meteor explosion, but here’s a video of another, unrelated meteor.”

LOL.

Aqua4U April 25, 2012 at 8:56 PM

Ooops..

Comments on this entry are closed.

Previous post:

Next post: