Month: August 2015

The Perseids is my favorite meteor shower of the year, and this year is likely to be the best one in recent memory. Here’s when, where, and how to watch it—and just what is going to make this year so spectacular.

Top image: 2010 Perseids / image courtesy of Michael Menefee.

What Are the Perseids?

The Perseids are an annual meteor shower that greets us at the end of each summer. We’ve actually been seeing a few Perseids scattered around the sky since early last month, but the bulk of them will spill over into the sky tonight and tomorrow night. But if the Perseids are just one meteor shower out of several a year, what is it that makes it the absolute best?

Part of it is timing. Some astronomers will try to convince you of the superiority of cold-weather meteor showers, mumble-lying something (usually through chattering teeth) about “clarity” and “crispness.” Don’t be fooled: Summer meteor showers are absolutely where it’s at, and the Perseids peaks at exactly the right moment of the season, just as summer is winding down, but well before any sort of cold snap has fully hit.

But even more than the season, the Perseids appeal is really all about the fireballs.

Image: 2012 Perseids over Wyoming’s Snowy Range / David Kingham.

Comet Swift-Tuttle is responsible for the Perseids—the dust and ice from its trail is what we’re watching burn up in our atmosphere when we see meteors. Swift-Tuttle orbits Earth every 133 years and the closer it is to us, the thicker that trail—and the Perseids that we see here below—becomes. The comet is not due to come closest to us again until 2126, but that still leaves a pretty thick cover for us to see this year, with NASA estimating rates of at up to 100 meteors visible per hour.

Image: GIF of Swift-Tuttle orbit, made from data generated with JPL’s small body database.

That meteor shower rate alone would make for a pretty fantastic show. Fireballs, however, are a very special subsection of those meteors. They are unusually big and flashy, with a brightness higher than that of either Jupiter or Venus, and often even brighter than the moon.

Image: 2010 Perseids: Yes, they really are that bright / David Kingham,

The number of fireballs that you see during the Perseids simply blows every other meteor shower out of the water. It has more on average than every other meteor shower combined, excepting the Geminds and the Orionids.

Image: Fireballs over five years charted / NASA.

Even the Geminids, the only shower that comes close in number, just doesn’t touch the Perseids in terms of brightness. The Perseids are simply the biggest, baddest, and brightest meteor shower around.

Okay, but why is this year so special, then?

So, if the Perseids are pretty active every year, what makes this year exciting? Well, it’s more about what we’re not getting, than what we are. That’s right, I’m talking about our old enemy, the moon.

Image: The moon’s phases for all of 2015 timelapsed / NASA.

The new moon actually falls on August 13th, but the moonlight tonight from the almost completely waning crescent should also be pretty much negligible, meaning that for the two nights when the Perseids will be falling the thickest, we’ll have almost complete darkness against which to watch.

Image: 2010 Perseids / Fred Bruenjes via NASA.

Of course, moonlight isn’t the only enemy of the meteor shower: There’s also cloud cover. But even that is looking likely to be not much of a problem for most areas this year, with the weather looking relatively clear around the country.

When (and where in the sky) can I see the Perseids?

At a rate of over 100 Perseids per an hour, simply looking up should be enough to see at least a few. The majority of them, though, will be clustered around the top of the constellation Perseus. If you’re having trouble tracking that, look for Cassiopeia first, Persesus is below it, and the radiant—the spot where the meteors appear to branch out from—should hover somewhere right between the two:

Image: International Meteor Organization.

As for timing, you’ll see a few as soon as it gets dark but things will start to really heat up at around midnight. From then, you’ll have all night until the dawn to catch the show.

Okay! I’m in. So, how do I get ready to watch this thing?

Let’s get this out of the way: This particular meteor shower is going to be bright enough and bold enough that even a quick trip to your own backyard or rooftop is likely to yield at least something to be seen. But with just a bit of time and preparation, we can do far, far better. So let’s do it.

Where do I watch it?

The first thing you’re going to want to do is pick out a place to watch from. Make sure you drive out far enough that you’re out of range not just of the light, but of anything—whether buildings or trees—that’s going to get between you and your view of the sky. Keep an eye on the terrain around you, both natural and human-made, and try and get yourself to some higher ground, particularly those of you reading us from out in the mountains.

Image: Star trails from the 2013 shower at the Mount Lemonn Sky Center, Adam Block / University of Arizona.

If you want, you can connect with a local astronomy group, many of whom are planning group events this week. Not only will they know the good spots near you to set up camp, there will also likely be plenty of telescopes, binoculars, and cleverly-aimed cameras among the crowd to get a closer look at what you’re seeing.

But really, there’s no need to overthink it: a blanket spread out in the grass, any likely-looking patch of dark sky, and nothing but your own eyes will also do you just fine.

2010 Perseids / image courtesy of Michael Menefee.

What do I need to bring?

You don’t really need much, but there’s a few things you may want. You (wisely) chose to check out a summer meteor shower, but a light jacket isn’t a bad thing to have on hand—you may be out there for quite some time and it can get cooler around dawn. Similarly, some water, snacks, bug spray, and a blanket or two will probably be appreciated at some point in the night. I also have an old star wheel I like to bring, for ease of constellation tracking. But there are plenty of good apps as well that will get the job done as well (Sky Map is my personal choice). Just make sure you’ve downloaded your star map app of choice to your phone before you head out.

Image: GIF made via footage from NASA.

Some people will also tell you that this is a good time to break out the camping chairs. Those people are wrong and possibly seeking some kind of obscure and elaborate revenge against for you for murky reasons. Keep an eye on them, and then remember that you’re going to be tilting your head upwards for hours, possibly from midnight clear up until dawn. So make it easy on yourself and your neck: reclining chairs, a lie-down on that blanket you brought, even the hood of your car will all do quite nicely for our purposes.

Ugh, it’s cloudy/my car broke down/I’m trapped in a submarine. Why is everything the worst?

Why, indeed? But, cheer up, friend! It’s meteor shower day, the most wonderful day of the year. And, even if you can’t see it yourself, you can still share it with the rest of us through these sites:

• NASA’s Marshall Space Flight Center will be livestreaming the shower starting at 9 p.m. (Central time) tonight, complete with an astronomer’s commentary and a Q&A session.
• The Slooh Observatory will be broadcasting their view of the Perseids tonight as well, beginning at midnight.
• If you’re in the mood for something a little different, you can also opt to listen to the meteor shower as well, or to be more accurate the sounds of the meteors echoing against our radar. Pair it with your own IRL skyview—it’s delightfully eerie.

Image: 2010 Perseids / ESO.

via Gizmodo
The Best Meteor Shower of the Year Is Tonight, and Here’s How to Watch it