what does a planet have to have to be a planet??????????????????????????

Question

I really do need this for shcool and it would be helpful if someone could look on "NASA.GOV" to try to find it I can't

PLEASE HELP

Answer 1

The new classification of bodies in our solar system:

1. Planets
2. Dwarf planets
3. Small solar-system bodies

To be a "classical planet", the object must:

* orbit the Sun,
* be massive enough for its own gravity to pull it into a nearly round shape
* clear the neighborhood around its orbit.

To be a "dwarf planet", the object must comply with the first two rules above, but not the third. Also, the object must not be a moon. All other objects orbiting the Sun are "small solar-system bodies."

Answer 2

Here is the formal, newest definition:
A planet, as most recently defined by the International Astronomical Union (IAU), is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, not massive enough to cause thermonuclear fusion in its core, and has cleared its neighbouring region of planetesimals.

So, in clear language:
1) it has to be big enough: you could not have something the size of Earth be a cube. The gravity would rapidly pull down the corners and the cube would become rounded. If an object has a strange shape, chances are that it is way too small.

2) It can't be too big: otherwise, the pressure of all that mass, at the centre, will trigger nuclear fusion and you'll have a star, not a planet.

3) There can't be more than 1 on the same orbit

Ceres, Pallas, Juno and Vesta were planets until around 1850. They were OK with rules 1 and 2 but not with number 3. The status of planet was taken away from them when the 5th, 6th, 7th... asteroids were found on similar orbits.

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A planet does not need to have an atmosphere (even though the ones in our system do) nor does it need to sustain life. It doesn't even need bedrock (check out Jupiter).

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NASA does not define what is a planet. It is the International Astronomical Union (IAU)

Answer 3

I don't know about "independently" orbiting. The exact wording of the definition is:

1) A planet is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.

The debates have clarified that "clearing its orbit" refers to the process that happened during the formation of the planets. It does not talk about the presence of bodies that later strayed into the orbit after the accretions took place, nor to objects in resonant orbits.

The definition may be difficult to apply outside our solar system.

(2) A "dwarf planet" is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape [2], (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.

Answer 4

1. It must be an object which independently orbits the Sun
2. It must have enough mass so that gravity pulls it into a roughly speroidal shape
3. It must be large enough to "dominate" its orbit (ie. its mass must be much larger than anything else which crosses its orbit

these were determined in 2006 when pluto was demoted because it does not meet the third requirement.

Answer 5

don't tell people to go do your research for you. you could go to NASA.GOV as easily as I could. Planets have bedrock and atmosphere. There is your answer you whining little chit.

Answer 6

To keep it simple, it has to sustain life. Examples, plants, animals, etc... Also, abundant of water.