Get Ready for the Geminid Meteor Shower overnight this Friday/Saturday

As usual at this time of the year, the Earth is entering a stream of debris from rock comet 3200 Phaethon, which is the source of the annual Geminid meteor shower. Forecasters expect the shower to peak on Dec. 13-14 with as many as 120 meteors per hour.

This year the nearly full Moon will reduce the number of meteors you may see but it is still well worth a look. Expected to peak from about midnight Friday Australian Eastern Daylight Time (or 1300 UT) until 9pm (1000 UT) Saturday, this meteor shower will be visible in both hemispheres.

Though you do need to keep in mind that meteor showers often peak hours before or after predictions and for sure we certainly don’t know everything that a given meteor stream might have in store!

This shower is an interesting one though, with an equally interesting history and source. The Geminids were first identified as a distinct meteor shower by R.P. Greg of Manchester UK in 1862, and the estimated ZHR rose from about 20 to 80 through the 20th century. The parent source of this shower remained unknown until 1983, when astronomer Fred Whipple linked them to the strange “rock-comet” body 3200 Phaethon. This is an Apollo asteroid also thought to be a member of the Pallas family of asteroids, 3200 Phaethon seems to be shedding enough material to produce the annual Geminid meteor shower. This makes the annual shower rare as one not produced by a comet. It’s worth noting that 3200 Phaethon also passes extremely close – 0.14 AU – from the Sun at perihelion, and gets periodically “baked” during each 1.4 year passage.

In the 21st century, rates for the Geminids have stayed above a Zenith hourly rate (ZHR) of 120, now the highest of any annual shower. It’s worth noting that an extrapolated ZHR of almost 200 were seen in 2011 when the Moon was at an equally unfavorable waning gibbous phase! The Geminids always produce lots of fireballs, capable of being seen even under moonlit skies.

With our warmer nights down under it is a great time to get out and have a look! Jupiter is also looking good after about 10:30pm and Mars and Saturn are visible in the early dawn skies as well.

Eta Aquarid Meteor Shower May 3-6

Just a reminder that the Eta Aquarid meteor shower will peak this weekend and into early next week, this shower is associated with Halley’s Comet.

The Moon will be a very slim crescent by the time the Eta’s peak on the morning of the 6th May (Monday).

It is advisable that you try to observe at least the morning before and after the peak as the maxima is very broad for this shower and it is quite possible that rates can vary.

The expected Zenith Hourly Rate is around 65 meteors per hour, but realistically this may be much lower, this shower has shown good rates in the past.

Best observing time is from around 3:30am.
The meteors will appear to “radiate” away from the star Eta Aquarii, meteors closer to the radiant will appear much shorter and ones further away will leave longer streaks, of which you can trace the origin back to the radiant.
Any meteor NOT tracing back to the radiant is classified as “sporadic” or could be a member of another shower which might be showing activity.
Some meteors near the radiant will show as a rapid pinpoint flash of light indicating a “head-on” meteor, don’t worry they won’t hit you!

Look for fast (65km/sec) white/yellowish coloured meteors which leave a 2 to 3 second “train” (sometimes longer), ie: the streak left over after the meteor “burns” out.

There will be some early morning International Space Station passes in the NE on the morning of the peak (6th May) at around 4:21am but will keep low (17 degrees) above the horizon!

Thanks to my pal – Chris Wyatt for the reminder and chart!

Lyrids Meteor Shower, peakings around tonight April 23rd.

Head out early tomorrow morning between midnight and dawn to catch the Lyrids Meteor Shower.

The Lyrids radiant is close to the constellation of Lyra (a harp). The constellation rises just after midnight in the southern hemisphere and moves across the northern sky. The Lyrids meteor shower is best viewed after midnight o well before sunrise on 23/24th April. Point your feet towards the northern sky and look about 45 degrees above the horizon. You should see a really bright white star there – this is the blue white star Vega. This shower is caused by the Earth’s atmosphere passing through the dusty pebbly debris left over from Comet Thatcher and has been known to produce spectacular meteors.

So what is a meteor? As a comet (which is a large ball of rock and ice from the outer Solar System) passes by the Sun they become quite heated up and they begin to shed gas, ice, dust particles and rocks which we see as the comets tail. This is left behind as the comet continues on its journey around the Sun.  If the comet’s orbit intersects that of the Earth’s orbit some of material strikes our atmosphere and we see a meteor.

Comet Thatcher also known was discovered by an American amateur astronomer A.E. Thatcher in 1861. This comet was the brightest in over half a century and both head and tail were visible together in broad daylight. Every spring for at least the past 2,700 years, Earth has passed through the trail, thrilling countless sky watchers with the sight of flaming dust and grit. In 1803, it was reported that it looked as if the entire sky was alight with flaming stars.

The Lyrid meteors strike our atmosphere about 95 kilometres above the earth and at speeds of around 49 km/sec or 175,000km per hour and can burn up in some pretty amazing fireballs.

Typical meteoroids which is the name given to meteors before they hit the atmosphere – range in size from grains of sand to walnuts. The bigger they are, the brighter. A meteor that actually hits the ground – a rare event fortunately is called a meteorite.

So if you want to have a look –  find somewhere away from street  lights and other bright lights where you can see clearly to the north and east. head out early in the morning either just after midnight – although the Moon will make it harder to see some of the dimmer meteors o around about  3:30 to 5 a.m. toting a thermos of hot chocolate, tea or coffee. Make sure you’re suitably rugged up for the weather and get yourself all comfy in a reclining lawn chair, banana lounge or under a blanket or sleeping bag. No special equipment required.  Look towards the North and enjoy the beauty of the early morning sky and see how man meteors you can see.

Eta Aquarids Meteor Shower May 5/6 2012

The Eta Aquarid meteor shower is the first of two showers that occur each year as a result of Earth passing through dust released by Halley’s Comet, with the second being the Orionids.  The point from where the Eta Aquarid meteors appear to radiate is located within the constellation Aquarius. This shower definitely favours the Southern Hemisphere observer as they

Created in Stellarium - finder for the eta aquarids

are usually a lightish meteor shower producing about 10 meteors per hour at their peak in the Northern Hemisphere but can peak at around 40-50 per hour here in the Southern hemisphere in a dark sky. The shower’s peak usually occurs on May 5 & 6, however this shower tends to have a broad maximum so viewing should be good on any morning from May 4 – 7.

The full moon which occurs on May 6th will probably ruin the show this year, washing out all but the brightest meteors with its glare.

But still worth having a look if you are up, to see how many Eta Aquarids can be seen in the moonlit sky. For the most part, this is a pre dawn shower. The radiant for this shower appears in the east-south-east at about 4 a.m. local time (wherever you are) and the hour or two before dawn usually offers the most meteors.