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.
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.
Application deadline for grants from the Barringer Family Fund for Meteorite Impact Research is April 6, 2012. This program provides 3 to 5 competitive grants each year in the range of $2500 to $5000 USD for support of field research at known or suspected impact sites worldwide. Grant funds may be used to aid with travel and subsistence costs, as well as laboratory and computer analysis of research samples and findings. Masters, doctoral, and post-doctoral students enrolled in formal university programs are eligible. For more details and an application, please go to: http://www.lpi.usra.edu/science/kring/Awards/Barringer_Fund/index.html
The Barringer Family Fund has been established as a memorial to recognize the contributions of Brandon, Moreau, Paul, and Richard Barringer to the field of meteoritics and the Barringer family’s strong interest and support over many years in research and student education. In addition to its memorial nature, the Fund also reflects the family’s long-standing commitment to responsible stewardship of The Barringer Meteorite Crater and the family’s steadfast resolve in maintaining the crater as a unique scientific research and education site.