Simply setting up a camera to take a series of images of the night sky can pick up a lot more than a few stars.
If you have a wide-angle lens, and live near a large city there is a good chance that some aircraft will fly into the field of view. The linear streak and alternating lights are a dead give-away of a plane having crossed the camera’s field of view. If you don’t have the alternating lights, it’s mostlikely an orbiting satellite reflecting sunlight.
Meteors are also somewhat of a common occurrence. These are easily recognized by their characteristic increasing than decreasing brightness as they burn up in the upper atmosphere. The meteor in the image above is from the Geminid shower.
The last artifact comes for outside our solar system, it is cosmic rays. The CCD or CMOS sensor of your camera works by performing an electric read-out of photons captured by the lens. Cosmic rays are high-energy sub-atomic particles that have traveled through space and managed to make it through the atmosphere down to us. The one in the photo above just happens to hit my camera sensor. As the near light-speed sub-atomic particle smashes into atoms on the sensor it looses energy, freeing up electrons which register as “light” by the CCD. Most of the time the cosmic ray will hit the sensor straight on, but sometimes it impacts at a shallow angle and causes a series of pixels to “light” up, as in the photo above.
Take time to examine your photos, you never know what surprises you may find.
With the Geminids peaking tonight and a clear sky after two nights of snow, I charged the camera battery and got a quick setup going to take some pictures of the sky. As for any nigh sky photo, both lens stabilizer and auto-focus is set to OFF and focused manually at infinity. Then found a corner of the yard shielded from stray lights and planted the tripod, roughly aiming the camera 70deg up and pointing east (the constellation Gemini was rising at 10pm).
However at -15C outside, the old battery wouldn’t last very long. I left it running for about 30 minutes, taking 20 seconds exposure at ISO 800 with a 17mm F4 lens. The camera is now thawing (covered with frost after bringing it indoors) and will wait until tomorrow before checking the pictures out.
Setup for the 2017 Geminids
In the brief moments that I was outside I caught a 2-3 meteors and one really bright one (easily visual magnitude -4). So even living in the city, the Geminids are visible and accessible to all. With my feet deep in snow I wasn’t dressed well enough to hang around in the cold wind to watch the show for long. So I hope the camera managed to capture a few.
It’s that time of the year again: the Geminid meteor shower. It is visible almost all the month of December, however the best and peak viewing, with up to 120 meteors an hour, is between December 12 and 15. It should be a good year because we are heading towards a new Moon on December 18th, so no bright moon to ruin the show.
This meteor shower is called the Geminid because the radiant (apparent direction of travel in the sky) of the meteors is centered on the constellation Gemini. However the source of the debris is not a comet like most other meteor showers, but an asteroid: 3200 Phaethon. The asteroid and orbit were discovered in 1983 and is too good of a match with the Geminids to be anything other than the source of the debris. However its makeup is closer to asteroid belt material, so it may very well be a 5km chunk from a larger asteroid, with all the associated debris.
To watch the Geminids, the best time is past midnight as the constellation will rise east around 10pm. The higher it is in the sky the better. The Geminids do regularly create fireballs: bright displays that can exhibit colour and even leave a smokey trail, so observation even in light polluted city sky is possible.
Here are some tips for the observation:
- Dress to be warm. You’ll be sitting still in the cold night. Nothing will get you indoors faster than the shivering knowing that warmth is only a few feet away.
- Lay down or recline in a chair. Standing and looking straight up is very uncomfortable and quite the strain on the neck.
- Give yourself a good 15 minutes for your eyes to adjust to the darkness If you give up after 2-3 minutes, your eyes are still adapting to night vision and will miss the fainter meteors.
- Find a spot away from sources of lights. Of course heading out of the city is best, but if you can’t, just find a spot in your backyard without the glare of street lights and neighbors’ porch lights. That also means no electronic screens to ruin your night vision.
You can also setup a camera on a tripod to see if you capture some of the meteors. Grab a short focal length, remove auto-focus and go for a 10-20 second exposure setting.
Yesterday, even if I’m located in the light polluted Montreal suburb, I decided to head out at quarter to midnight to see if I could by chance spot one or two bright meteors from the Perseids shower. As luck would have it in the 15 minutes doesn’t looking around Cassiopeia I spotted two before clouds and a rising moon sent me indoors.
But during that time scanning and waiting, it got me thinking… It took me a good minute to find a suitable spot in my backyard free of the light from the neighbours’ houses and street lights. If there was less light pollution we could have darker skies and everyone could enjoy the show.
During Earth Hour people are asked to turn off the lights for one hour to support the fight for climate change. But I always found that pretty pointless. If you want to fight climate change, it’s an every day affaire, in your daily routine and the choices you have as a consumer, not one hour in an entire year. So the one hour lights out is more of a gimmick, doesn’t really benefit anyone. But if we had an evening of lights out during the peak of the Perseids meteor shower wouldn’t that be great!
The Perseids falls in August when it’s warm and sitting outside past sunset in the cooling air is enjoyable. Kids don’t have school so they can stay up late. And the patio furniture is out, that’s all the required equipment.
So what do you say? Light out for the 2018 Perseids? I think that’s a worthwhile collective movement.
The Perseid meteor shower is scheduled to peak tonight, but a large Moon will ruin the show. The best time is tonight (August 12) after 11pm, looking north-east.
While the sky directly overhead may look darker, it’s better to look 45degrees over the horizon to see a thicker “slice” of the atmosphere.
While the Taurid Meteor Shower is expected to peak on November 11th and 12th for the Northern Hemisphere, some fireballs have already been observed and recorded.
The following video was recorded in Bangkok Thailand just before 9pm local time November 2nd
And a few days prior to that the following was captured in Poland on October 31st.
These fireballs as they streak across the sky often produce color due their chemical composition and the heat generating entering the atmosphere. Some may even leave behind a smoke trail that will persist for some time.
The Taurid Meteor Shower are remnants of a large comet that probably got broken up by repeated close encounters with Earth and other planets 20,000 to 30,000 years ago.