Editor's note: The 2017 Lyrid meteor shower will peak just after midnight on Saturday, April 22, but will be visible from April 16 to April 25. See our viewing guide here: Lyrid Meteor Shower 2017: When, Where & How to See Its Peak This Week
The Lyrids are a prominent meteor shower that peaks in late April. While the shower is not as flashy as others during the year, the Lyrids have been known to have unusual peaks of activity. A typical shower has 10 to 20 meteors an hour at the peak, but some of the more fruitful ones over the decades showed reports of 100 meters an hour — or more.
Chinese astronomers recorded the shower as far back as 687 B.C., according to NASA. The source for the meteors is Comet Thatcher, which was discovered by A.E. Thatcher on its last closest approach to the solar system in 1861. The comet is expected to return in 2276.
Historical Lyrids sightings
The Lyrids have been chronicled in many cultures for the past 2,700 years. Chinese astronomers noted prominent displays in 687 B.C. and 15 B.C. Also, in A.D. 1136, a report from Korea chronicled the shower with the words "many stars flew from the northeast," according to SPACE.com skywatching columnist Joe Rao.
In 1803, residents of Richmond, Virginia, went outside late at night after a fire alarm. A report from that time noted that the meteors resembled rockets in the sky.
"Shooting stars. This electrical [sic] phenomenon was observed on Wednesday morning last at Richmond and its vicinity, in a manner that alarmed many, and astonished every person that beheld it," wrote a journalist at the time, in an account republished on Space Weather.
"From 1 until 3 in the morning, those starry meteors seemed to fall from every point in the heavens, in such numbers as to resemble a shower of sky rockets."
NASA stated that other heavy shower sightings took place in 1922 (Greece), 1945 (Japan) and 1982 (United States.)
The Lyrids appear to emanate from the constellation Lyra, which gives the meteor shower its name. The "radiant" point is easy to spot in the summer sky because Vega is one of the brightest stars, making it visible even in spots with light pollution. The meteors, however, are best viewed under dark skies. Lyra's location is:
- Right ascension: 19 hours
- Declination: 40 degrees
- Latitudes: Between 90 and -40 degrees
NASA recommends that skywatchers go outside after Lyra rises (after 9 p.m. local time), and after moonset, to watch the show — which runs until dawn. Allow 30 minutes for eyes to adjust, and look away from the radiant, as longer and "more spectacular" meteors will be visible. Gazing at Lyra directly will show short meteors due to a phenomenon known as foreshortening.
While the Lyrids are not the brightest ones out there, NASA said the meteors "are known for their luminous dust trains, which can be observable for several seconds." A typical meteor from that shower moves about 30 miles (49 kilometers) per second.
The shower appears to come from a portion of the sky, but in reality it is due to leftovers of Comet Thatcher. Comets disintegrate as the sun's heat causes ice and other debris to break off the core. This leaves a trail of rubble in space. In the case of Thatcher's path of debris, the Earth runs into it once a year and produces the sky show.
It's hard for astronomers to predict which years will produce more spectacular showers, the North American Meteor Network noted in a report from 1999.
"The orbit determination relies heavily on photographic and radar results, which are seldom obtainable every year — hence gaps in the data and our knowledge of the shower," the network wrote. "Studies of the years with higher Lyrid activity have found, however, that outbursts of fainter meteors occurred prior to the normal meteor maximum."