Spaceweather.com - 4/24/13
For the past few days, Earth has been passing through a stream of debris from ancient Comet Thatcher, source of the annual Lyrid meteor shower. According to international observers, the encounter produced as many as 25 meteors per hour. Some of these were fireballs. NASA's All Sky Fireball Network detected more than 30 Lyrids as bright as Venus on the nights around the shower's April 22nd peak. Here are their orbits:
In the diagram, the red splat marks the location of Earth; green elipses are the orbits of the meteoroids, triangulated by multiple cameras in the meteor network.
"The purple ellipse is the orbit of Comet Thatcher," adds Bill Cooke, lead scientist for NASA's Meteoroid Environment Office. "The orbits of the comet and the meteoroids match up nicely." According to Cooke, the Lyrid fireballs penetrated Earth's atmosphere as deeply as 44 miles above the planet's surface, traveling at an average speed of 105,000 mph.
The shower is subsiding now as Earth exits the debris stream.
