There’s one thing great about sitting underneath the night time sky, watching a meteor bathe play out overhead. Nonetheless, observers within the southern hemisphere normally get the quick finish of the stick, with many of the greatest showers strongly favouring these north of the equator.
Each Might, nevertheless, southern observers get a particular deal with – the Eta Aquariid meteor bathe. This 12 months situations promise to be excellent, making it the best alternative for some autumnal meteor remark.
The forecast peak for this 12 months’s Eta Aquariids falls on the morning of Saturday, Might 7. The Moon is effectively out of the way in which, so meteors gained’t be misplaced in its glare.
However what if skies are cloudy? Properly, should you miss the morning of the height, don’t panic! The Eta Aquariids are famed for his or her broad peak, and meteor charges sometimes keep excessive for a few week across the peak (Might 4–11). So if Saturday morning is cloudy, attempt wanting once more on Sunday, and even Monday.
To get the most effective view, you’ll need to stand up within the early hours of the morning and be effectively away from any brilliant metropolis lights. Give your eyes time to regulate to the darkness. Take a chair or recliner to get snug, calm down and gaze skywards.
You gained’t even want a telescope! To greatest observe meteor showers, you’ll need to watch as extensive an space of sky as doable. Utilizing a telescope or binoculars would make the spectacle virtually unattainable to look at.
Mud and particles from a well-known comet
Because the Earth orbits the Solar, it regularly runs into mud and particles from comets and asteroids. Each April and Might, the Earth spends about six weeks traversing a river of mud left behind by the well-known Comet 1P/Halley.
Comet 1P/Halley was photographed on March 8, 1986, throughout its final go across the Solar.
NASA/W. Liller
Each 76 years or so, Comet Halley swings near the Solar. Its icy floor heats up till the ices boil off into house in a course of known as “sublimation”. This shrouds the comet in a gaseous coma, which is blown away from the Solar to generate the comet’s tail.
The gasoline escaping Halley’s floor carries mud grains, which step by step unfold across the comet’s orbit. Some transfer forward of the comet, whereas others lag behind.
Over 1000’s of years, the house round Halley’s orbit has develop into thick with mud grains. The comet is basically shifting by means of a unclean snowstorm of its personal making! And annually, the Earth runs by means of that broad river of mud – giving beginning to the Eta Aquariid meteor bathe.
Curiously, the Earth runs into Halley’s particles once more in October, producing the well-known Orionid meteor bathe. However we get a greater present in Might annually with the Eta Aquariids, as that is once we transfer nearer to the centre of the mud stream.
Learn extra:
Hundreds of satellites are polluting Australian skies, and threatening historic Indigenous astronomy practices
The place ought to I look?
When mud left behind by a comet smashes into Earth’s environment, it turns into a spectacular fiery streak of sunshine excessive within the sky. This normally occurs about 80km above the bottom, though the most important bits of particles can penetrate fairly deep into the environment earlier than burning up fully.
The mud grains in a meteor bathe all transfer across the Solar at basically the identical velocity and in the identical course. This implies the grains are additionally travelling in the identical course as they hit the Earth.
However as they transfer in the direction of an observer on the bottom, that observer’s perspective will make their paths diverge, and they’re going to appear to be radiating out from a single level within the sky. That time is named a bathe’s “radiant”.
The Orionid meteors are a terrific instance of how meteors in a bathe appear to radiate from a single level within the sky.
Phil Hart
Meteors showers are named for the constellation by which their radiant lies. So the Eta Aquariids have a radiant close to the star Eta Aquarii – the tenth-brightest star in Aquarius.
To see the Eta Aquariids, you’ll want to attend till the radiant rises – earlier than that, the physique of the Earth will get in the way in which. We’re fortunate right here within the southern hemisphere, because the Eta Aquariid radiant rises within the east at round 1:30 to 2am, native time.
The Eta Aquariids radiant will rise between 1.20am and a pair of.20am for cities throughout Australia.
Museums Victoria
Whereas the Eta Aquariid meteors could be seen wherever within the sky, the best place to see the most effective variety of meteors is about 45 levels to the left or proper of the radiant itself.
Luckily, this 12 months we have now one other spectacular sight within the morning sky. 4 planets – Saturn, Mars, Jupiter and Venus – will all be in a line. To see the most effective meteor present, look about 45 levels to the left or proper of this line of planets.
The road of planets and the Eta Aquariid radiant as they’ll seem at round 4am on Might 7 from Sydney (rising within the east). The sky will look principally the identical from Brisbane, Canberra and Perth at 4am (native time), Melbourne, Hobart and Adelaide at 4:30am (native time) and Darwin at 5am (native time).
Museums Victoria/Stellarium
To see how the planets and radiant will rise out of your location, go to the Stellarium planetarium web site, set your location and transfer the date and time ahead to the morning of Might 7. Should you activate the “constellations” and “constellations artwork” (on the backside of the display screen), you’ll be able to watch Aquarius and the planets rising from the consolation of your laptop.
What number of meteors ought to I anticipate to see?
The Eta Aquariids are the second greatest bathe of the 12 months for folks in Australia. They’ll placed on a spectacular present – however don’t anticipate to see meteors falling like snowflakes.
When the radiant first rises above the horizon, at round 1.30am, meteors from the bathe shall be few and much between. Should you see 5 – 6 Eta Aquariids in that first hour, it is best to most likely rely your self fortunate.
That stated, these early meteors may very well be actually spectacular. Referred to as “Earth grazers”, they typically appear to streak from close to one horizon all the way in which throughout the sky. Earth grazers are the results of meteors hitting our environment at a really shallow angle, virtually edge on. They’re uncommon, however unbelievable to witness!
Because the night time goes on, and the radiant climbs greater into the sky, the variety of meteors ought to enhance. Within the hour earlier than daybreak, you can simply see 20 to 30 meteors per hour.
Oh, and a phrase of warning: meteors are like buses – should you’re anticipating 30 per hour, you’ll be able to simply wait ten minutes and see nothing, earlier than three come alongside without delay. Be sure to costume heat so you’ll be able to keep underneath the celebrities for not less than half an hour, if no more!
Learn extra:
Searching galaxies far far-off – this is how anybody can discover the universe
