A meteor is seen as a bright flash, or streak of light in the night sky.
They are caused when objects as small as grains of sand impact the Earth’s atmosphere at high speed and heat up due to extreme friction.
The larger to original object, the brighter the meteor. Some will even be seen as a fireball, a spectacular, slower-moving ball of light.
What is a Meteor Shower?
Meteors can be seen in dark skies at any time and can come from any angle, so you can look for them on any clear night, but the rate of these ‘sporadic’ meteors is quite low. However, throughout the year there are a number of predicable meteor showers that will provide (hopefully) a much greater number of meteors to observe.
As Comets pass through our Solar System they leave dusty trails behind them. When the Earth passes through one of these trails some of the particles of dust fall into the Earth’s atmosphere and you get a meteor shower. As the Earth travels on its orbit around the sun, it passes through the same dust trail once a year, so you get a repeating meteor shower.
In this project we will plan and observe a meteor shower, noting the rate of meteors, direction of flight, colour and type.
This might seem like a basic project, needing nothing more than a your own eyes, a notebook and a Deck Chair (Optional, but comfortable) but I find that I end up ‘Meteor Spotting’ during most of my observing sessions and it a great way to learn the value of keeping an Observing Log.
How to Observe a Meteor Shower
To plan to observe a meteor shower, you need to know when a meteor shower will be visible. There are a number or regular showers throughout the year.
Pick an observing site with a clear view of as much sky as you can. Dark areas well away from any city lights are best. Avoid street lights, or other bright lights. Check out the Finding a Dark Site page for more tips.
Get comfortable. Dress warmly and get a reclining lawn chair and pillow to sit on. Insect repellent can be VERY useful in summer!
Moonless nights are best because the sky is at its darkest and more meteors will be visible. It takes your eyes about 20 minutes to reach their maximum sensitivity in the dark (Dark adaptation).
Although meteors will follow a path from the radiant constellation, they can become visible at any point in the sky, so try not to focus on one area of the sky. Usually you will see more meteors after midnight because that’s when the night side of Earth faces in the direction in which it’s moving around the Sun, So be ready for a late night.
Settle back and enjoy!
Here’s a list of the regular Meteor Showers through the year:
|Name||Radiant Constellation||Active Dates||ZHR|
|Quadrantid||Draco||January 1 to 5||40|
|Lyrid||Lyra||April 15 to 28||10-20|
|Eta Aquarid||Aquarius||April 19 to May 28||20|
|Delta Aquarid||Aquarius||July 12 to August 19||20|
|Perseid||Perseus||July 17 to August 24||60|
|Orionid||Orion||October 2 to November 7||10-15|
|Geminid||Gemini||December 7 to 17||75|
The ZHR is the anticipated number of meteors per hour.
Because meteors travel across the sky fast, from unpredictable directions and at unpredictable times, we need to be ready for them.
Some tripods (like mine) limit the amount of upward swing. you can avoid this by putting the camera on the tripod backwards. Look carefully at the image an note that the vertical adjustment bar it sticking out at the front, rather than the back.
Set your lens to give you as wide an angle as possible and the aperture to be fully open (f/ number as low as it will go) then find ANY bright star, point your camera towards it and see if you can see the star in the camera viewfinder. The viewfinder will dim the image quite a bit so it may be hard to spot the star.
If you can see the star then adjust the lens to focus the star. don’t worry if you can’t see the star, it will just make the next stage take a bit longer.
Set the camera to manual mode and set a 10 second exposure time. Use the cable release to trigger the camera. These prevent vibration in the camera which will give you a fuzzy picture.
Once the picture has been taken, review it on the camera (be careful not to touch the lens and adjust the focus) Zoom the image up and check that the stars are well focused, showing as sharp points and not doughnuts. If the focus is not sharp then your lens is either focused too long, or too short. To correct it pick a direction to adjust the lens focus (clockwise, or anticlockwise), move it just a bit and take another picture. If this one looks sharper then you are adjusting in the right direction. If not, switch direction. Keep going until the focus is sharp. See the Focus (Rough and Fine) page for more tips.
Now that you are happy with your focus, swing the tripod around so that the camera points in the general direction of the radiant constellation. Again, be careful not to touch the lens and adjust the focus.
Take a couple of test shots with long exposure times to ensure that the images don’t get washed out by ambient light. start at 20 seconds and go up to 1 minute. The goal here is get long exposures and better chance of catching a meteor, so you might want to drop your ISO setting a bit to around 400.
If your camera has its own Intervalometer function, set it to take 0 (infinite) shots of 30 seconds exposure with 2 a two second delay between shots. If the camera does not have an internal Intervalometer (like mine), an external one can be used.
Through the night you (or rather the Intervalometer) are going to take lots of images, so make sure you have spare batteries and memory cards for the camera.
Now you can sit back and enjoy the show.
Once the night is over, review your images to see what you have captured.