Plenty of man-made objects in sky to see
I don't think we'll ever need traffic reports for satellites over Butler, but since 1957, the dawn of the space age, more than 23,000 satellites have been launched into orbit around Earth and about a third of them are still in orbit.
In fact, Vanguard One, launched on St. Patrick's Day 1958, is still in orbit 52 years later. It's made more than 200,000 orbits around our world and has traveled more than six billion miles! Move over Energizer Bunny! Vanguard really keeps going and going and going!
Some satellites, like the U.S. Space Shuttle and the International Space Station, even have people in them.
Along with useful functioning satellites, there's also a lot of junk up there, including useless, out of commission and out of control satellites, spent rocket stages and other random space garbage. It's like a floating junkyard up above the atmosphere, in what some refer to as the "junkosphere."
Don't get me wrong, though, if you were ever lucky enough to grab an extra seat in the Space Shuttle or whatever takes its place and orbit the Earth once every 90 minutes, chances are you wouldn't see any garbage. There's a lot of space in space.
Just about anytime you stargaze you'll see starlike objects march across the heavens at a steady but sane pace. They're either seen in the early evening a little after twilight or just before morning twilight.
You're just about guaranteed to see at least one satellite zipping among the stars as you study the constellations. Satellites are seen mostly at those times because they're better able to reflect sunlight then. That's the only light they've got!
You could have the biggest floodlight ever created mounted on a satellite and have it shine back to the Earth and we'd still never see it. These satellites are at least 110 miles high, but most of the healthy ones are a lot higher than that. In fact, just by observing and comparing satellite speeds across the sky, you can estimate how high they are.
Most military reconnaissance and communications satellites are high flyers, at altitudes of 250 to 600 miles. They traverse the sky in two to three minutes, looking like brighter stars moving against the backdrop of actual distant stars.
Faster paced satellites are in much lower orbits, and in a lot of cases are not long for the orbital world. Lower trajectory satellites skim through the upper drag of the upper atmosphere, which slowly pulls them down, leaving them more and more vulnerable to being totally sucked in by the atmosphere and incinerated because of air friction.
That was the fate of Sputnik One, the first Russian satellite, and Explorer One, the First U.S. orbiter. Sputnik was launched in Oct. 1957 and burned up in the atmosphere just four months later. Explorer One, however, was launched in February 1958 and stayed in orbit until March 1970. We built them to last back then!
What powers these satellites as they circle our world? They're certainly not propelling themselves. The answer is good old fashioned Newtonian physics. Satellites are always falling toward the Earth in a curving path, much like a thrown baseball curves down toward the ground.
However, satellites are traveling at a fast enough speed after their launch that the curve of their fall matches the curvature of the Earth. They never hit the ground, provided they're high enough above the dragging atmosphere.
Most satellites travel from west to east across the sky, taking advantage of Earth's east to west rotation, which is faster toward the equator. That's why just about all U.S. space launches are at Cape Canaveral, Fla., as opposed to Fairbanks, Ala.
Some satellites travel in polar orbits south to north or vice versa. A lot of those are spy satellites so wave when you see them. There are also satellites that are geostationary and sit in one place above the Earth with their orbits in perfect sync with Earth's rotation.
The brightest satellites are the International Space Station and Space Shuttle. They are almost as bright as high flying aircraft, sometimes more so, especially when they're docked together.They can even be brighter than the very dazzling Jupiter, now in the southeastern evening sky. In fact, if conditions are right it's even possible to spot the International Space Station during the day. It's gotten that big over the years.Another really fun group of satellites to watch are the 60 plus Iridium satellites that provide worldwide cell phone service.About the size of an old Volkswagen bug, the satellites track across our heavens and rotate. As they do they dramatically flare up in brightness for a few seconds at a time when the angle of one of the solar panels is right between you and the distant sun.Sometimes Iridium flares are more than 100 times brighter than the brightest stars. This temporary flash is caused by the highly reflective solar panels on the satellites kicking all kinds of reflected sunlight our way.Presently, there are nearly four dozen satellites you can easily see with the naked eye, even in areas of city and suburban light pollution. There are some absolutely wonderful websites for keeping track of them and many, many more fainter ones. Of course, they'll also help you track the Space Shuttle and the International Space Station.One of the websites is Heaven's Above and you can find it at www.heavens-above.com. After you set it up for your location, you can keep track of every major spacecraft and satellite.The brightest ones are listed at 3.5 visual magnitude. If something is coming over this area, the website will tell you where and when to look for it. It also lists and tracks the times of Iridium flares as they spike in brightness.There's another, arguably even better, website called Real Time Satellite Tracking at www.n2yo.com/?s=25544. I love that site because it automatically reads your location from the IP address on your computer.It'll give five day predictions for the visibility of the International Space Station and many other satellites, help you make a viewing log and even show you maps of the satellite orbit and where it's at in that orbit. You can literally "watch" it orbit different parts of the world. I think it's so cool.You can even track Vanguard One, but actually spotting it in the sky requires a large telescope and a lot of skill.We're running out of time for this, but there's one thing you always want to look for when the U.S. Space Shuttle heads over this area.If the sun's angle is just right, sometimes you see a faint patchy cloud ahead of the Shuttle. You know what that is? It's toilet and other waste dumped by the shuttle. It precedes the Shuttle in the sky because of the law of conservation of angular momentum.When they dump waste from the Shuttle they shoot it out below the Shuttle so it can't get sucked back in — that's not considered astronaut friendly!What ends up happening is the potty cloud winds up in a lower orbit, and because of angular momentum, the shuttle waste zips ahead of the shuttle, truly becoming number one (and two) on the runway of space!Mike Lynch is an amateur astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis and is author of the book, "Pennsylvania Starwatch," available at bookstores and at his website: www.lynchandthestars.com.
