Animation of 1P／Halley orbit - 1986 apparition

The Eta Aquariids are a

meteor shower A meteor shower is a celestial event in which a number of meteors are observed to radiate, or originate, from one point in the night sky. These meteors are caused by streams of cosmic debris called meteoroids entering Earth's atmosphere at extre ...

associated with

Halley's Comet Halley's Comet or Comet Halley, officially designated 1P/Halley, is a short-period comet visible from Earth every 75–79 years. Halley is the only known short-period comet that is regularly visible to the naked eye from Earth, and thus the o ...

. The shower is visible from about April 19 to about May 28 each year with peak activity on or around May 5. Unlike most major annual meteor showers, there is no sharp peak for this shower, but rather a broad maximum with good rates that last approximately one week centered on May 5. The meteors we currently see as members of the Eta Aquariid shower separated from Halley's Comet hundreds of years ago. The current orbit of Halley's Comet does not pass close enough to the Earth to be a source of meteoric activity. Although this shower is not as spectacular as the

Leonids The Leonids ( ) are a prolific meteor shower associated with the comet Tempel–Tuttle, which are also known for their spectacular meteor storms that occur about every 33 years. The Leonids get their name from the location of their radiant i ...

may be and well below the rates of the

Perseids The Perseids are a prolific meteor shower associated with the comet Swift–Tuttle. The meteors are called the Perseids because the point from which they appear to hail (called the radiant) lies in the constellation Perseus. Etymology The name ...

or the

Geminids The Geminids are a prolific meteor shower caused by the object 3200 Phaethon, which is thought to be a Palladian asteroid with a " rock comet" orbit. This would make the Geminids, together with the Quadrantids, the only major meteor showers ...

, it is not an ordinary event. The Eta Aquariids get their name because their radiant appears to lie in the

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the e ...

Aquarius Aquarius may refer to: Astrology * Aquarius (astrology), an astrological sign * Age of Aquarius, a time period in the cycle of astrological ages Astronomy * Aquarius (constellation) * Aquarius in Chinese astronomy Arts and entertainment ...

, near one of the constellation's brightest stars, Eta Aquarii. The shower peaks at about a rate of around a meteor per minute, although such rates are rarely seen from northern latitudes due to the low altitude of the radiant. The Eta Aquariids are best viewed in the pre-dawn hours away from the glow of city lights. For northern observers, the radiant of the shower is only above the horizon for the few hours before dawn, and early-rising observers are often rewarded with rates that climb as the radiant rises before sunrise. The shower is best viewed from the

equator The equator is a circle of latitude, about in circumference, that divides Earth into the Northern and Southern hemispheres. It is an imaginary line located at 0 degrees latitude, halfway between the North and South poles. The term can als ...

to 30 degrees south latitude. The activity is fairly constant from one return to the next. However, in 2013, the maximum ZHR exceeded the average level significantly for about two days. An explanation was presented by Mikiya Sato (Sato & Watanabe, 2013), showing that the meteoroids are from very old ejection from the parent 1P/Halley and are trapped probably in resonances to Jupiter's orbit (similar to the Orionids observed between 2007 and 2010). The peak ZHR reached 135 ± 16. Updated information on the expected time and rates of the shower is provided through the annual IMO Meteor Shower Calendar.

References

External links

Worldwide viewing times for the 2016 Eta Aquarids meteor shower

Detailed information on the 2011 maximum of the Eta Aquarids, courtesy of the International Meteor Organization

Your Guide To Watching This Week's Halley's Comet Meteor Shower
{{Meteor showers April events Halley's Comet May events Meteor showers

See also

References

External links