It can be expected to change gradually over time, but the difference from one year to the next, or even in thousands of years, will be insignificant.
Anything in an orbit is constantly accelerated. If that sounds peculiar to you, it's because you think 'accelerate' means 'speed up'. It doesn't. It means 'change speed or direction or both'. If an object is not moving at a constant speed in a straight line, then it's accelerating. An object in an orbit is constantly changing direction. So it's constantly being accelerated, even if its speed never changes.
Asteroids orbit the sun at several tens of thousands of miles per hour. The speed varies depending on the orbit.
Mainly, it has to: (1) Move at a sufficiently high speed. Near the Earth's surface, that would be about 7.9 kilometers per second (7900 meters per second). You can multiply the meters per second by 3.6 if you prefer it in kilometers/hour. (2) Be sufficiently far from Earth, to avoid air resistance. A height somewhere between 100 and 200 kilometers is required, for a relatively stable orbit. Comment: I think "in a circular orbit" is what the question is looking for as the answer.
No. The speed of any orbiting body depends only on the energy of its orbit, meaning mainly its distancefrom the central body.When a Space Shuttle astronaut performs a 'space walk', and momentarily unhooks his feet from thehull of the shuttle, he and the shuttle are both in earth orbit. The astronaut and the shuttle have thesame orbital speed, and they stay close together, even though the shuttle has somewhat more massthan the astronaut has.
Orbiting bodies travel faster at the closest point of approach to the primary. Planets and comets travel fastest at perihelion, the closest point of approach to the Sun. With comets, it's really obvious; Halley's Comet, for example, orbits between close the Venus to beyond Neptune. In its 76-year orbit, it spends about 3 years inside the orbit of Jupiter, and 73 years beyond it. Same with Earth and the other planets, although the eccentricity of Earth's orbit is only about 3%. So the difference between "fast at perihelion" and "slow at aphelion" isn't very much. The Earth reaches perihelion in January, so that's when it is moving fastest. If the people in Australia wanted to brag about how their summers are hotter than ours in the Northern Hemisphere because they're closer to the Sun during their summer, they would have a very good point!
8600000000mph
No. An A.U. is the average radius of the Earths orbit around the Sun. (which can be measured in light years or light minutes (about 8) if you want).
That's a 'geosynchronous' orbit. If it also happens to be over the equator, so that the satellite appears to stay at the same point in the sky, then it's a 'geostationary' orbit.
Average speed is an average value of speed over a given time. If your speed is constant (not changing), then your average speed will equal your speed at any given moment in time.
We know that the answwer must be "No", simply because we know that NOTHING is faster than the speed of light.
5.43 km per second.
Its speed will vary greatly as its orbit is highly eccentric. It will be slower when further out from the sun on its 11,000 year orbit. Its average speed is around 1.04 km/s.
If an object is moving in a circle (like a teather ball or a planet in orbit, although orbit is not a perfect circle), then its velocity is always changing (remember that velocity is speed AND direction, and since the direction is changing, the velocity is changing). It's position is also always changing as a result of having a velocity.
The Moon orbits Earth at an average speed of 3,700 km/h (2,300 mph).
It is the orbital velocity (speed and direction) or orbital speed (rate of motion). It is usually stated as "average orbital speed" but is actually "mean orbital speed."
If a satellite is in an elliptical orbit around the Earth, the Earth will be at one of the focii. The speed of the satellite will then constantly be changing. It will move the fastest when it is nearest to the Earth (perigee) and slowest when it is furthest away (apogee).
car is not always moving at constant speed