Jerb322Do satellites have different levels for direction they are traveling?
brianorcaOrbits are circles or ovals, and the satellite must always be moving to stay in orbit. But the time to go around depends on the distance, so there is a distance where the satellite takes 24 hours to go around, which matches the Earth’s rotation, which is geosynchronous. A subset of these is called geostationary, when the orbit is a circle around the equator, so it stays in the same spot of the sky. (Then we can aim a ground antenna just once and don’t have to adjust it.) Satellites at this distance add 1/4 second delay to any signal because of light speed. This orbit is very tight, since it can not vary in altitude by more than a few hundred meters. (More than that would cause them to drift east or west out of the assigned spot.) There are a limited number of “slots” in this orbit to keep the satellites safely separated and to prevent their signals from overlapping. Most of these are used for communication, especially TV. A few are for weather, as they can watch an entire hemisphere constantly.
Other satellites operate in a lower orbit. Here the orbital period can be as low as 90 minutes. Most of these orbits are inclined so they pass over most of the earth instead of just the equator. The orbit (circle) stays in one angle while the earth rotates underneath. Satellites here get better images because they are closer to Earth, but take a day (or more) to see everything. They also have greatly reduced light speed delays. These orbits eventually decay because of tiny amounts of air at that altitude.
That’s crazy. TIL about geostationary satellites. I didn’t think a satellite could ‘stay still’ in space above an area and have wrongly told people it’s not possible. I have some comment edits to make.
Well, the satellite isn’t standing still in space. It’s orbing Earth. It just happens to oribt Earth at the exact same speed and direction as the earth is orbiting so it just looks like it’s standing still from Earth.
Wait till you hear about legrange points. These are points where 2 massive object (like the sun and earth) create a sort of pocket where a satellite can orbit “nothing”. I have massively simplyfied it, off course.
Heard of them (UFOs sub, lots of heavy reading, skimming the physics parts) but never knew what they were. That’s a great understandable explanation, thanks.
The JWST actually sits at a Lagrange Point (L2)
There is a good write up including video and animations to explain what where and why webb.nasa.gov/content/about/orbit.html
Orbit - Webb/NASA
The James Webb Space Telescope (sometimes called Webb or JWST) is a large infrared telescope with a 6.5-meter primary mirror. Webb is the premier observatory of the next decade, serving thousands of astronomers worldwide. It studies every phase in the history of our Universe, ranging from the first luminous glows after the Big Bang, to the formation of solar systems capable of supporting life on planets like Earth, to the evolution of our own Solar System.