In recent years, we’ve talked about the season of spring – in particular, the few weeks around the March equinox – as being a good time to see especially bright meteors, aka fireballs. The story began with a 2011 report by NASA meteor expert Bill Cooke, who was quoted as saying:
Spring is fireball season. For reasons we don’t fully understand, the rate of bright meteors climbs during the weeks around the vernal equinox.
NASA said in 2011 that, in the weeks around the start of northern spring, the appearance rate of fireballs can increase by 10-30 percent.
2016 was a good year for fireballs around the time of the March equinox, too, according to the American Meteor Society (AMS). Vincent Perlerin of AMS reported on six major fireball events over the U.S. between March 2 and March 8, 2016.
This year, there have been bright fireballs reported by the AMS, as there always are. But the rate of bright fireballs – at least so far – doesn’t compare with 2016.
Why does would there be a fireball season? Why should there be more fireballs at one time of year than at another? The American Meteor Society said one reason might be:
… the fact the antapex radiant lies highest above the horizon this time of year during the evening hours.
So … what is the antapex radiant? You might have heard the term apex of the sun’s way to describe the direction our sun is moving through space, with respect to the stars. Our sun and family of planets travel more or less toward the star Vega in the constellation Lyra; and that is the apex of the sun’s way.
NASA has a different view on the possible cause. A NASA website has suggested:
The reason why is still unknown, but one hypothesis is that more space debris litters this section of Earth’s orbit.
Meteors are debris from space. They typically range in size from a few feet (about a meter) to smaller than a grain of sand. As these objects enter Earth’s atmosphere, they vaporize due to friction with the air.
NASA scientists have set up a network of ground cameras that track and record video of meteors flaming overhead. The footage can be used to pinpoint a meteor’s orbit and origin. Watch the video to learn more.
Speaking of meteors, while spring might be the best time to see fireballs, major meteor showers – sometimes featuring a meteor or more every minute – take place throughout most of the year, with a break between the Quadrantids in early January and April’s Lyrid meteor shower. The next meteor shower will be the Lyrids in April.
Deborah Byrd created the EarthSky radio series in 1991 and EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. "Being an EarthSky editor is like hosting a big global party for cool nature-lovers," she says.