There could not be a better way to spend a balmy August evening than lying out on the ground watching meteors race across the night sky. Simply turn off your TV — there is nothing interesting on anyway — and head out with a blanket or a lounge chair and maybe a little mosquito repellant.
Even though we refer to them as “shooting stars,” meteors are not stars at all. Stars are big, far bigger than the earth, and crazy hot, like millions of degrees. If they were falling down on us, it would be terrifying to say the least. Thank goodness the stars are a long ways away.
Every year at this time, the earth in its orbit around the sun passes through a stream of space junk left over from Comet Swift-Tuttle. What we see shooting across the sky are little chunks of rocks about the size of a kernel of Grape Nuts cereal barreling into our atmosphere at a speed of 20 to 40 miles per second. A bigger chunk, say the size of a pea or a marble, would produce a sight you would remember for the rest of your life. Those little bits of rock get really hot really fast from the friction with the air. They heat up a thin column of air which glows white-hot for a second or two and that hot air is what we see.
They will appear to be coming from the constellation of Perseus, hence the name. You can see them anywhere in the sky so keep looking around. Do not stare at just one spot.
There is a problem with this year’s display, however, a big, bright problem: the moon. It is going to be almost full and will drown out a lot of the dimmer meteors. Do not let that discourage you, though, a moonlit night is always a treat. Find a place where a tree or your house will block the moon and allow you to view a large swath of dark sky. After midnight is best on the mornings of Aug. 11, 12 and 13. Most predictions put the morning of Aug. 13 at the peak of the shower.
If you do not want to stay up that late, before midnight is the time when, if you are very lucky, you might spot an earth grazer. These meteors come in at a shallow angle to our atmosphere and just skim the earth, so to speak, sometimes heading back out into space. Two years ago I saw one of these at the Methow Valley Chamber Music Festival with a group of kids who had decided that the music was not really their thing. Everyone else was inside the barn and we were out looking at Jupiter through my telescope, when we were treated to one of the most incredible meteors of my life. Brighter than the full moon, it slowly traversed the entire sky, spitting out a long tail of brilliant red and green sparks. You never know what you might see up there, so keep looking.
Find the Milky Way
August is one of the best times of the year to see the Milky Way, our home in the vast cosmos. You have to expand your perspective a bit to even begin to understand what you are looking at. Meteors are tiny and not that far away. The Milky Way is the second-largest thing you can see with the naked eye and it is really far away.
Humans have seen this sight for thousands of years, but only in the last 100 have we even begun to understand it. Imagine a pinwheel shaped configuration of hundreds of billions of stars of which our sun is just one insignificant member.
Look for a glowing band of light stretching all the way across the sky from north to south. In the south, two planets straddle its girth, brilliant Jupiter to the right and dimmer Saturn to the left. Notice that neither is twinkling, which is a big clue that they are planets, not stars.
In between Jupiter and Saturn is the very heart of the Milky Way galaxy. It is difficult for astronomers to see into its center because of all the clouds of dust and gas in the way. Like the dreadful Minotaur lurking at the heart of the labyrinth on the island of Crete, a monster lies hidden at the core of the Milky Way, a massive black hole devouring anything that gets too close.
Here are a few fun facts about our home galaxy that you may not have known. It is not named for the candy bar. I cannot believe how many people have told me that is where they think the Milky Way got its name. I hope they were not serious! In Latin it was called Via Lactea, the way of milk, and it refers to the breast milk of a divine goddess spewed out across the night sky.
It is really big. Do you want to take a tour of our galaxy? If you get on one of our fastest rocket ships, the trip across that big pinwheel would take hundreds of millions of years.
Most of it is made up of stuff we cannot see. All the stars, planets, dust and gas make up less than 10 percent of the total contents of the Milky Way. The other 90 percent plus is something called dark matter, and not only can we not see it, we do not even know what it is!
We are not sitting still. Looking up at the stars we cannot perceive any indication of motion. That is because the distances are so huge and our lives are so short. Actually our sun is cruising along at over 500,000 miles an hour through the Milky Way, tugging the earth and the other planets along with it.
Have fun with the meteor shower and be sure to check out the Milky Way. To see it in all its grandeur, a moonless night is best.