Mars

[Eyersey1234]

Why is Mars's year longer than an earth year?

[The Mad Monk]

Because Mars is farther away from the sun, it has to travel a greater distance around the sun. It takes Mars about twice as long as it does for Earth to make one circle around the sun.

[Eric Mc]

The further a planet (or any object) is away from the sun, the slower it travels around the sun. That means, combined with the greater distance covered by its orbit, the "year" on that planet will be longer than for a planet closer in.

Mercury, which is only 36 million miles away from the sun, has a year of only 88 earth days.

Neptune takes 165 earth YEARS to travel once around the sun.

[The Mad Monk]

Eric Mc said:

The further a planet (or any object) is away from the sun, the slower it travels around the sun. That means, combined with the greater distance covered by its orbit, the "year" on that planet will be longer than for a planet closer in.

Mercury, which is only 36 million miles away from the sun, has a year of only 88 earth days.

Neptune takes 165 earth YEARS to travel once around the sun.

Why don't they move faster?

[Eric Mc]

Newton's and Kepler's Laws.

[welshjon81]

Earths orbital distance 584 million mliles
Mars orbital distance 1,426 million miles

[XM5ER]

The Mad Monk said:

Why don't they move faster?

In layman's terms, because they'd fly off into space.

[AshVX220]

XM5ER said:

The Mad Monk said:

Why don't they move faster?

In layman's terms, because they'd fly off into space.

But I take it they are all actually moving faster than Earth through space though aren't they?

[CrutyRammers]

The ones further out have a higher velocity, yes. It's like swinging a weight around you on a bungie. Close in , they take less time to go around. Swing faster, the bungie will stretch and the weight will get further away and take longer to go around, but will be travelling faster.

[The Mad Monk]

CrutyRammers said:

The ones further out have a higher velocity, yes. It's like swinging a weight around you on a bungie. Close in , they take less time to go around. Swing faster, the bungie will stretch and the weight will get further away and take longer to go around, but will be travelling faster.

Lets see if I have got this right.

Presumably, any planets going round too fast would have, long ago, passed out of the Sun's gravitational field and gorn orf into outer space?

We are left with the planets that have a stable orbit from Mercury out to Pluto.(If we still count Pluto.)

Is that about it?

[Eric Mc]

More or less. Early in the life of a solar system, planets and other bodies are being shuttled around by gravitational interactions. Some crash into each other or into the parent star. Others are flung out of orbit to become interstellar nomads. What's left are the objects that have settled into (more or less) stable orbits.

[CrutyRammers]

The Mad Monk said:

Eric Mc said:

The further a planet (or any object) is away from the sun, the slower it travels around the sun. That means, combined with the greater distance covered by its orbit, the "year" on that planet will be longer than for a planet closer in.

Mercury, which is only 36 million miles away from the sun, has a year of only 88 earth days.

Neptune takes 165 earth YEARS to travel once around the sun.

Why don't they move faster?

To come back to this one a bit, the speed defines the orbit, rather than the orbit defining the speed. The faster an object is travelling, the higher its orbit will be. So if it moved faster, it would also move further away from the sun.