Ever look up in the evening skies just staring at the constellations, and suddenly notice a tiny illuminated dot floating gently across the expanse only to vanish into nowhere seconds later? That may have been the kin of an object launched into space over 50 years ago, a manmade satellite called Sputnik.

It was 52 years ago this week that the Soviet Union surprised us all by launching the first artificial satellite into orbit around our planet. Just a faint, almost invisible speck in the night sky, it collected data on the atmosphere and launched something of its own, namely the Space Race which ultimately led to our landing on the Moon.

Presently there are literally thousands of tiny manmade objects floating around up there. But doing what exactly? And how do we see one in action?

Satellites are used for a multitude of things. We addicts of Google Earth know that some satellites are up there taking a lot of high resolution, close up and personal pictures of our planet. For some, too personal. And people with GPS devices in their cell phones absolutely depend on satellites to get around.

Speaking of cell phones, there are also instruments in orbit for phone communications, and television, and radio.

Scientists use special instruments onboard satellites to see parts of the electromagnetic spectrum we cannot see. For example, with infrared detectors we can "see" the temperatures of landforms and ocean surfaces.

And of course, there are satellites not looking down on us, but looking up, out into the universe, like the legendary Hubble Space Telescope.

If you have never seen one with the naked eye, here's how.

After the sun sets, when the sky is finally dark enough to see a lot of stars, just go out in your yard, lay down and look up. That's all there is to it. Occasionally you may see a tiny fleck of light moving slowly but deliberately across the starry sphere. You will not see the red and green lights of an airplane, just that white dot.

Why early in the evening? Because it is then that the sun's light is gone for us, but not for a shiny satellite a couple hundred miles above Earth. They continue to reflect the light long after we on the surface are in the dark.

In fact, you may notice a satellite vanishing suddenly, before it gets anywhere near the horizon. That's because it is orbiting into the Earth's giant shadow. Unable to reflect the light of the sun, it fades to black.

Don't expect to see Sputnik up there. It burned up on reentry just months after its famous launch. Such is the eventual fate for most satellites.

Until next time, clear skies!