Of all the meteor showers of the year, the best easily has to be the Geminds. With up to 120 shooting stars per hour, often in a variety of colours, and occurring in Australia's summer, this is the meteor shower to watch out for. The peak will be on the evening of the 14th and the morning of the 15th, which falls in the middle of the week. However, as the meteor shower runs from the 7th to the 18th, there will plenty of opportunities for viewing this great astronomical show.
Image courtesy of Jason Jenkins @ Flickr
About the Geminids
Meteor showers are caused by clouds of dust particles that are left behind by an object orbiting the sun. Normally this is a comet, but in the case of the Geminids, it is thought that the cloud of dust comes from an asteroid, 3200 Phaethon. This is a rock comet, or to put it simply, it is a solid rock similar to other asteroids, but it follows an orbit similar to a comet.
The name of the meteor shower comes from the radiant point, in this case, the constellation Gemini. This is where the shooting stars appear to originate from in the sky.
Image the constellation Gemini courtesy of Till Credner @ Wikimedia
The shooting stars themselves are usually little more than specks of dust. It is wrong to say that they run into the Earth because it is actually the Earth that smashes into the cloud of dust. The raw ridiculous speed of the Earth is so fast that the dust heats up as it comes into the atmosphere, burning brightly. Sometimes you might see a fireball or a shooting star that is caused by dust that is as large as a grain of sand.
Multicoloured shooting stars are caused by the different elements in the meteorite. Iron will glow yellow, silicon red and copper green.
Watching the meteor shower
Typically when viewing meteor showers the best time is from midnight to before the first light of predawn. While this is mostly true of the Geminids, they do start to appear earlier than many other meteor showers, around about 9 or 10 pm in some areas around Australia, though the peak is still in the early hours of the morning.
Photograph courtesy of Amir shahcheraghian @ Wikimedia
Meteor shower watching requires that you get away from city lights. This can mean heading off to bushland areas, mountain tops, or my favourite, beaches. The radiant point is the constellation Gemini, but the shootings starts are actually less likely to appear there than everywhere else in the sky. However, it can be useful to look for the radiant point when it is close to the horizon as the meteors are then most likely to appear in that quadrant of the night sky.
So once you have found somewhere dark, get rid all light. That includes camera screens, phone screens, campfires and iWatches. It takes about 20 minutes for your eyes to adjust to the dark, so sit or lie back and watch the skies. Just keep looking with up 120 shooting stars per minute predicted you should be seeing one or two every minute.
Viewing details around Australia
The Geminds runs from December 7 to 18 with the peak evening being the night of the 14th to the morning of the 15th. You can go and view the shooting stars on any night, but the information below is for the peak evening. On other nights it will be roughly the same. The main issue is to check moon rise, set and location because the moonlight can interfere with your evening sky watching by blocking out shooting stars.
In Sydney and Melbroune , viewing on the night of the 14th starts at about 11 pm. Though I think it would be better to wait until later when the radiant point is higher in the sky but before 3:45 am, when a crescent moon pops up over the horizon trying to spoil your viewing. However, as the core of the meteor shower will be to the north, so the moon won't really be a problem.
In Brisbane ,the Geminds can be veiwed from about 9 pm in the sky to the North East, and while the peak viewing time is around 4 am, you will be better off looking for them between 11 pm and 2:30 am before the rise of the moon. Though the waning crescent moon won't be too much of a problem.
In Adelaide ,you need to wait until nearly midnight for viewing the meteor shower and you should get the best view from 1:30 am right up until dawn, with the moon only turning up at 4 am.
Over in Perth you can watch the meteor shower from 10 pm until dawn, but of course after midnight will be better, especially as moonrise is not until after 3 am.
Photographing a shooting star
Capturing a shooting star in a photo is a combination of a good camera, the right settings, patience and a great deal of luck. Yes, you do need a decent camera such as DSLR or mirrorless camera. Shooting stars are both quick and fairly faint so you want to use the fastest lens you have. Your typical lens will have the smallest, that is fastest, f-stop setting of f/3.5. If that is the fastest lens you have, then use it. But if you have a f/2.5 or even better, f/2 lens, then that will be better.
Set up your camera with a nice view of the sky. The tricky bit is how long you should set the exposure for. The most common exposure length would be about 10 to 25 seconds. Though of course with a faster lens you will want to use a shorter setting. On the other hand, the longer the exposure will capture more of the star field, and if the sky has even some light in it, capture some of the scenery as well.
Photograph courtesy of Amir shahcheraghian @ Wikimedia
Shooting stars are too fast to hit the button when you see one, so you need to have the camera on continuous shooting mode. If you are with friends, turn off the camera screen to avoid messing with their night vision. Basically, you let the camera take lots of photos and then go through the shots to see if you captured a shooting star. With the expected frequency of the Geminids, your chances are pretty good. In fact, often photographs of the Geminids contain more than one shooting star.