The Ten Most Important Satellites Orbiting Earth Now
First, two caveats: most of these satellites are representative of an entire class of satellites. There may be others that serve similar functions, but the satellites listed are exemplars. Also, the list is obviously U.S.-centric. If you live in Europe or Asia, there are likely different satellites that fill the roles of these all-star orbiters.
Hubble Space Telescope - By taking thousands of breathtaking photos unhindered by the blurring effects of Earth's atmosphere, the Hubble has brought the beauty and mystery of space to more people than any other observatory, not to mention the massive amount of scientific research accomplished with it.
Galaxy 14 - This communications relay carries digital TV signals for much of the east coast, including ESPN, Lifetime, Sci-Fi, CNN, A&E and my personal favorite, the History Channel.
GOES-12 - From its high-altitude geosynchronous orbit, GOES-12 keeps a constant watch on weather conditions in most of North America.
The Moon - Tides, werewolves, the Apollo Program: without our natural satellite, we'd have none of these things.
KH-13 - This U.S. spy satellite is so secret, even the name is probably wrong (the government started giving them random names after people caught onto to the KH numbering system). Who knows what black budget, cutting edge satellite intelligence gathering devices are capable of these days?
GPS IIR11 - The U.S. government's NAVSTAR program brought global positioning abilities first to the military, then to the general public. It takes a constellation of these things for the system to work, so IIR11 is just one cog among many. Without it, there'd be no geocaching!
GoldenEye - With the ability to fire an EM pulse that could have wiped out an entire nation's financial records, GoldenEye is typical of fictional satellites and representative of our fears of orbiting weapons.
International Space Station - It's a symbol of international cooperation and a frontier outpost in the quest to colonize space. The low orbit maintained by the ISS makes it one of the easiest satellites to spot with the naked eye.
NOAA 17 - Unlike the GOES satellites, the NOAA satellites have asynchronous orbits, spinning around the globe to spot developing weather patterns that affect billions of people.
LANDSAT 7 - NASA and the U.S. Geological Survey teamed up in the 1970s to create a catalogue of Earth images shot from space. Since then, not only has the data improved with huge advances in digital photography, but numerous companies (including Google) have licensed the images for their mapping software.