Monday, August 10, 2015

Things in the Sky

The Perseid meteor shower is coming up! After midnight on Tuesday, and again on Wednesday, an observer under a dark sky may see up to 100 meteors per hour - an average of nearly 2 per minute. If you live in a city, the light pollution will wash out most of the meteors, so the countryside or mountains will be a much better place to watch them.

Meteors start as small bits of material floating in space, usually dropped from comets that passed through the area. At this stage, they are called "meteoroids". When the earth passes through a cluster of these particles, they hit our atmosphere and burn up as meteors, and we have what's called a meteor shower. If you're looking up at the sky, and you see a streak of light zip a short distance and then disappear, this is a meteor.

One of the best things about this particular shower is that the moon won't come out all night, so the sky will be darker than usual - making it possible to see more meteors than in most showers.

If you go outside to a dark location, here are a few other things you may see:

During the day, anybody can tell an airplane when he/she sees one... but fewer can recognize them at night. If you see a bright star that has red and green lights on it, or makes a rumbling noise, or is flashing, it is probably an airplane. Note that if it's close to the horizon and is moving towards you, it might not even appear to be moving; this does not mean it's an alien spaceship.

Now if the "airplane" suddenly speeds up, zips over your house, and begins slowly descending as it vaporizes all your trees one at a time, it most likely is an alien spaceship. If that happens, take some photos and post them online so I can see.

Planets look like stars, except they don't twinkle as much and they're a lot brighter. I have seen Jupiter in broad daylight; imagine how much brighter it can be at night. People have reported Jupiter as an alien spaceship. Don't make the same mistake.

Artificial Satellite
An artificial satellite is a man-made object orbiting the earth. On any dark, clear night, you can see a few of these. If you see a single moving star that isn't an airplane, it's most likely a satellite.

Sometimes you may see a bright star (either moving or stationary) appear in the sky, as if out of nowhere. Then it fades away. This is called an iridium flare. It occurs when a satellite gets in a position so its solar panels reflect sunlight down at you. If the satellite is spinning, the flare can occur quite a few times in a row. I have seen this before, and it has gotten me quite confused.

International Space Station
The International Space Station, or ISS, is a large satellite in low Earth orbit. Sometimes it has people in it, but you won't be able to see the people. Instead, you would see what looks like a very bright star moving slowly across the sky. It's about as bright as an airplane, so you might confuse it for one. The difference is that there are no flashing lights or colors whatsoever. It's just a solid white light.

You aren't likely to see the ISS when you're watching meteors, but it's definitely a possibility.

You probably won't see the aurora borealis unless you live really far North, or there's a really big solar storm. It usually looks like blurry colored glowing streaks in the sky. Sometimes it looks like a diffuse glow in the sky. You've probably seen pictures, so you should know what I'm talking about. Auroras can be red, or blue, or a lot of other colors. It's said that one red aurora fooled some firefighters into thinking a city had been set on fire.

Near Earth Asteroids (NEA) are exactly what they sound like: asteroids near the planet Earth. They're extremely rare, so you probably won't see any. Plus, they're usually too dim to see. And even if you saw one, it would look like a satellite so you probably wouldn't be able to tell the difference. I'm not trying to sound pessimistic, but you probably don't even need to think about these things.

Oh, yeah! Think of giant spaceships sucking up helpless humans, and carrying them to galaxies far away. What fun! UFOs can take many shapes and forms, and are often mysterious to the observer. One common UFO sighting begins as a bright light hovering above the horizon for a minute or two. Suddenly, the light will zoom away. If the UFO moves close enough to the observer, he'll usually find that it has flashing lights and produces a roaring sound.

UFO is an acronym for Unidentified Flying Object. It's basically anything in the sky that the observer doesn't understand. Besides the UFO in the previous paragraph (which was an airplane, by the way), other common UFOs include cloud formations, weather balloons, and even the moon. Anything in the sky which is not understood by the observer is considered "unidentified," and is a UFO. A lot of people don't understand the sky, so most UFOs are man-made or natural phenomenon, not alien spaceships.

Illusions are very common during meteor-watching. These can be anything... you'll probably see a really dim shooting star, which will quickly disappear, and nobody else in your group will have seen it (even though they're all looking at the same place). Most of the time, the illusions don't seem very realistic... I've seen black dots on the sky (what? the sky is already black...!), and I've seen weird shapes flash briefly and disappear. Some of these are probably caused by the brain trying too hard to see meteors. Others are caused by involuntary eye movements. If you see an illusion, just ignore it.

So that's my list of stuff you might see during a meteor shower. Did I leave anything out? Post a comment below!