Every year around August 12/13th, the Perseid meteor shower peaks. It’s a fairly reliable shower that generates 60 or more meteors per hour. Unfortunately, this year the Moon is full at that time, washing out the sky and any fainter shooting stars.
Last year, photographer Siddhartha Saha shot a nice time lapse video of the Perseids:
At 10 seconds in, one of the meteors leaves what’s called a persistent train; a streak of vaporized material that sits in the upper atmosphere and glows. You can see the winds whipping it into a twisted shape. I’ve never seen this happen myself, but one day…
If you miss the Perseids, don’t fret: there are plenty of others this year. The Leonids and Geminids are also good performers. And any dark night will generally have a few to spot, just random pieces of fluff that hit us all the time. It adds up to about 100 tons of material a day burning up in our atmosphere, so why not go outside and see if you can spot any?
em>Tip o’ the Whipple Shield to BABloggee Anu R for the link to the video.
A pair of astronomers monitoring an all-sky camera got a surprise (PDF) when they checked data from last February: a half dozen meteors all seemed to come from the same spot in the sky, indicating they all had a common origin. After doing some calculations, they found that they probably come from a parent comet with an orbit that’s at least 53 years long. Moreover, the orbit of this comet crosses that of the Earth, meaning we may have a close encounter with this object sometime in the future.
And because I can sense the oncoming panic on the web over this news, let me break it down for you. I’ll give you the science (which is cool), how we know this unseen comet may be potentially, um, interesting, then the reason you don’t need to run around in circles screaming (spoiler: it’s rude to others nearby, but also unnecessary).
But just to be up front: should you panic? Nope. We know there are objects out there that could hit us in the future sometime. This comet is in many ways just another one. As I’ll point out below, we pass through lots of meteor streams, so there are plenty of other comets that could hit us. I know, I know, that doesn’t sound reassuring, but think about it: how often is the Earth hit by a comet? Not very often, despite having a few on the list of Potentially Hazardous Objects. So having one more we know about out there isn’t great, but in reality doesn’t really make things any worse for us.
That picture above is one of the meteors in question. You can see the streak as the tiny bit of rock (probably the size of a grain of sand) glowing as it rammed through the Earth’s atmosphere at about 35 km/sec (22 miles/sec, or nearly 80,000 mph). If you go out on any dark night, you’re bound to see the random meteor or five. But meteor showers are when we see lots of them in a short time, and they occur when the Earth passes through the dust debris left behind by a comet.
Most comets are dirty snowballs: dust, pebbles, and boulders held together by ice (water ice, but also frozen carbon dioxide and other things we normally think of as gases). This makes comets the litter bugs of the solar system, shedding material when the Sun warms them up and turns the ice into gas. The vapor blows off, and the looser material forms a ribbon or stream that stays more or less along the same orbit as the comet.
If the path of the comet intersects the orbit of the Earth, we plow through that material at the same time every year. Read More
This is a relatively nice shower to watch. There are usually 20 – 30 meteors per hour, so you’ll see one every few minutes. Sometimes — though rarely — it can peak at much higher rates, but I don’t think anything like that is predicted this year.
Watching a meteor shower is actually pretty easy. All you need is a big view of the open, dark sky — the fewer trees, buildings and lights the better — and something comfortable to relax on like a beach chair (the kind that opens up so you can lie on it). The best time to watch is after midnight; that’s when the Earth is facing into the oncoming bits of gravel and ice, and you see more meteors (like seeing more bugs hitting your car’s front windshield than the rear one). The Moon is not quite full, and should be low in the sky after local midnight. Not ideal observing conditions, but not too terrible.
If you want details, I wrote an article on 12 things you need to watch a meteor shower. It was written for the 2007 Perseids in August, but it still applies. Just dress warmly!
Also, the folks at the UK’s Sky at Night magazine put together a nice informational video about the Leonids and meteor showers (it’s from last year, but still relevant):
That’s it! Happy meteor hunting!
Leonids over Uluru image courtesy Vic and Jen Winter at ICSTARS.
The next couple of nights bring us one of the best meteor showers of the year: the Perseids. It peaks around mid-August — this year the peak is tonight, Thursday August 12 — when the Earth plows through the debris from the comet Swift-Tuttle. This year should be pretty good, as the Moon sets early, and won’t interfere with seeing fainter meteors.
If you don’t think the Perseids will be cool, then watch this:
Love it! Want more info?
Back in 2007 I wrote up a brief guide on how to observe the Perseids, and it’s still pretty much apropos of the shower this year (just replace "Sunday" with whatever day you’re observing). The most important things: the later you go out, the better since the shower really peaks after midnight; you need a clear view of as much of the sky as possible; and you don’t need any equipment, but I recommend a lounge chair to lie back on.
Other sites are covering this as well, of course:
So get out there and enjoy the shower!