There is something wonderful about sitting under the night sky and watching a shower. Observers in the Southern Hemisphere get the short end of the stick, with most of the best showers favoring those north of the equator.
The Eta Aquariid meteor shower is celebrated by southern observers every May. It's the perfect time for some autumnal meteor observation because of the perfect conditions.
The peak of this year's Eta Aquariids will be on the morning of Saturday, May 7. If you are in the US, you can see Australia-time here. The moon is out of the way so it won't show up in the sky.
But what if the skies are overcast? If you miss the morning of the peak, don't worry! The peak of the Eta Aquariids is a week around the 11 May. If Saturday morning is cloudy, try to look again on Sunday or Monday.
If you want to get the best view, you need to get up in the early hours of the morning and be away from bright city lights. Give your eyes time to adjust. Relax and gaze skywards in a chair or recliner.
You will not need a telescope. To see the best of the shower, you need to watch as wide a area of the sky as possible. It would be hard to see the spectacle using a telescope or binoculars.
The Earth runs into debris from comets and asteroids as it circles the Sun. The Earth spends about six weeks traversing a river of dust left behind by a famous comet.
Every 76 years or so, a comet swings close to the Sun. The ices boil off into space in a process called "sublimation". This shrouds the comet in a coma, which is blown away from the Sun to generate the comet's tail.
Dust grains spread around the comet as the gas escapes. Some are ahead of the comet while others are behind.
The space around the moon has become thick with dust grains over thousands of years. The comet is moving through a snowstorm. The Earth runs through a broad river of dust each year, which causes the Eta Aquariid meteor shower.
The famous Orionid meteor shower occurs in October when the Earth runs into debris from Halley. We get a better show in May when we move closer to the center of the dust stream.
Dust left behind by a comet creates a fiery streak of light in the sky. The largest bits of debris can penetrate deep into the atmosphere before burning up.
The dust grains in a shower all move in the same direction. The grains are traveling in the same direction as they hit the Earth.
As they move towards an observer on the ground, that observer's perspective will make their paths diverging, and they will seem to be coming from a single point in the sky. That point is known as a shower.
The meteors in the shower seem to come from a point. Phil Hart.
The shower is named for the constellation in which it lies. The tenth-brightest star in the constellation is the Eta Aquarii.
The body of the Earth is in the way of the view of the Eta Aquariids. In the Southern Hemisphere, the Eta Aquariid radiant rises in the east at around 1:30 to 2 am, local time.
The best place to see the best number of Eta Aquariid meteors is to the left or right of the radiant.
There is a spectacular sight in the morning sky this year. There will be four planets in a line. To see the best show, look to the left or right of the planets.
The museums are Victoria/Stellarium.
The line of planets and the Eta Aquariid will appear at around 4 am in Australia.
You can see how the planets and radiant will rise from your location by visiting the Stellarium planetarium website, setting your location and moving the date and time forward to the morning of May 7. You can watch the planets rising from the comfort of your computer if you turn on the constellation and constellation art at the bottom of the screen.
The second best shower of the year is the Eta Aquariids. They can put on a great show, but don't expect to see a lot of meteorites.
There will be few and far between meteors from the shower when the radiant first rises above the horizon. If you see at least five Eta Aquariids in the first hour, you should be happy.
These early meteors could be spectacular. They often seem to streak from one horizon to the next across the sky. Earth grazers are the result of meteorites hitting our atmosphere at a very shallow angle. They are rare, but amazing to watch.
The number of meteors should increase as the night goes on. You could see up to 30 meteors per hour in the hour before dawn.
If you expect 30 per hour, you can easily wait ten minutes and see nothing, before three come along at once. If you want to stay under the stars for at least half an hour, make sure you dress warm.
Professor Jonti Horner and Senior Curator of Astronomy at Museums Victoria are both alumni of the University of Southern Queensland.
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