First things first, assuming you do have clear skies, meteor viewing requires no specialist equipment. All you need to do is to, well, look up. Of course, standing around in the dark looking up for long periods of time isn’t terribly good for your neck, so you can take your observing session up a notch and recline in a comfy chair or even just lie on the floor. It’s a social event! Invite your friends, family and neighbors and make a night of it.
However, although it’s the middle of summer in the Northern Hemisphere, sitting or laying still for long periods of time at night, depending on the weather, can still get chilly, so be sure to keep warm and lay on something soft.
So, Where to Look?
As I said, “up” is a good place to start, and so long as your eyes have adjusted to the dark, you shouldn’t have any problems spotting the Perseid meteors (or “shooting stars”) flash across the sky. But if you want to be even more pro, make sure you know where the constellation of Perseus is in the sky. Perseus can be found in the northeast between the bright star of Capella (that will be rising above the horizon after 11 p.m. local time) and the constellation Cassiopeia. SPACE.com has a handy night sky rendering that can help you track down Perseus.
Why Perseus? Well, that’s the reason why the Perseids are named after this constellation — it just so happens that the meteors from this particular shower at this time of year appear to originate in the general direction of Perseus. This is what is known as a “radiant” and all the other annual meteor showers throughout the year have been named after the constellation they appear to be radiating from. However, it is not necessary to stare directly at Perseus to see tonight’s Perseid meteors, just be aware they will be coming from that direction and sweeping directly overhead.
Now you know what direction they’ll be coming from and you know where to look (hint: “up”), what are the Perseids anyway?
The Perseid meteors are tiny grains of dust that originate from the periodic comet Swift-Tuttle. During the comet’s 133 year trundle around the sun, the ancient icy body has left a trail of dust and ice particles in its wake — much like a cometary contrail — looping around the sun. It just so happens that this trail of comet dirt crosses Earth’s orbit and, at this time in the Earth’s 365 day orbit around the sun, we hit the dust as regular as clockwork.
As Earth passes through the comet’s trail, these particles — called meteoroids — hit our atmosphere at high speed. With high velocity comes high gas pressure in front of each falling dust grain, triggering a phenomenon called “ram pressure.” This process compresses the air in front of the meteor, causing the atmospheric gases to rapidly heat up to over 3,000 degrees Fahrenheit (1,650 degrees Celsius). If the meteoroid is small, it is the ram pressure heating, not atmospheric friction (a common misconception) that vaporizes it, creating a bright, transient meteor and short-lived ionization trail. Bigger meteoroids may generate a bright streak of light as a meteor and then erupt as an even brighter “fireball,” the largest of which may even generate a bang that can be heard on the ground.
Which brings me to my next point…
What if it’s Cloudy?
A meteor’s ionization trail is usually all that remains of the vaporized comet dust that has impacted our atmosphere. Composed of ionized gas (atmospheric gas molecules that have lost or gained electrons), these trails rapidly dissipate, but they can be used to detect the frequency of meteors raining through the upper atmosphere (at around 60 miles in altitude). These ionized gases bounce radio waves back to Earth, a signal anyone with an FM radio set can detect, even if it’s cloudy. Check out astronomer Mark Thompson’s guide on how to do meteor spotting with a radio.
Of course, it’s not just by sight and radio that you can get involved in tonight’s Perseids peak; there’s always the internet.
During every meteor shower, various social media platforms, particularly Twitter, buzz with the #MeteorWatch hashtag. Connected to the UK-based MeteorWatch.org website, you can monitor the skies and report your meteor sightings from wherever in the world. Your meteor report is then logged and plotted on a dynamic map. For instructions on how to get involved, check out the MeteorWatch website.
Also, Slooh.com will be hosting a live online event for the Perseids tonight at 5 p.m. ET/8 p.m. PT, featuring professional astronomers and live feeds from their telescopes.
And of course, NASA will also be in on the action, covering the meteor shower live online with a webcast and expert guides. Many other astronomical and space organizations will be hosting their own events.
So, if you have clear skies tonight, get out there and enjoy the cosmic fireworks. The best time to see the meteors is after midnight in the early hours of Thursday morning (Aug. 13) as, like mosquitoes hitting a car’s windshield, the leading hemisphere of our planet will be rotating into the comet dust cloud at that time.
Read more at Discovery News
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