Are all planets circular or round in shape ??

Question

Do any one know if astronomers have discovered any non circular planets ? Why couldn't a planet be some odd shape ??

Answer 1

Any object with enough mass will be a spherical shape (though some will not be a perfect sphere due to rotation causing a bulge at the equator).

This is because the sphere is the most efficient shape to enclose a volume of mass, and the planets we know of so far are all massive enough that their gravity pulls the material in all directions towards the centre, creating basically a sphere.
The planets in other solar systems are spherical in shape, mainly because they have only found planets that are more massive than the Earth (and therefore the gravity of the object has caused it to be a sphere).
Even Mercury and Pluto (which are much less massive than the Earth) are sufficiently massive enough that their gravity has made them into spheres.

Asteroids and comets are not massive enough to pull the material in the object into a spherical shape.

Answer 2

A simple answer:
Planets seem to be spheres, not cubes or cylinders or oddball rocky shapes. Some smaller bodies such as asteroids or Mars moons Phobos and Deimos, do have odd shapes, but larger bodies like the nine planets and most of their moons do look like spheres. That's because of the nature of gravity. You can think of gravity as a force that points inward toward the center of the planet so that every part of the surface is pulled evenly toward the center, resulting in a spherical shape.
Of course, planets are not perfect spheres because mountains and valleys and even skyscrapers are all deviations from the spherical shape. However, as planets get larger, gravity gets stronger, until eventually large objects on the surface are crushed under their own weight. That's why we don't have mountains that are 50 miles high or skyscrapers that are 2,000 stories tall. Planets stay basically spherical because any large deviations get crushed.

Although gravity keeps planets close to spherical, there are other forces that cause deviations from the basic spherical shape. For example, the rotation of the earth once every 24 hours, causes an apparent centrifugal force which creates a bulge at the equator. In fact the earth's diameter at the equator is 7,926 miles while the diameter between the poles is only 7,900.

Answer 3

Well, not all planets are perfectly circular at all. As a matter of fact most are odd shaped...not square or triangular but maybe slightly oval. Some smaller bodies such as asteroids or Mars moons Phobos and Deimos, do have odd shapes, but larger bodies like the nine planets and most of their moons do look like spheres. That's because of the nature of gravity. You can think of gravity as a force that points inward toward the center of the planet so that every part of the surface is pulled evenly toward the center, resulting in a spherical shape. Of course, planets are not perfect spheres because mountains and valleys and even skyscrapers are all deviations from the spherical shape. However, as planets get larger, gravity gets stronger, until eventually large objects on the surface are crushed under their own weight. That's why we don't have mountains that are 50 miles high or skyscrapers that are 2,000 stories tall. Planets stay basically spherical because any large deviations get crushed.

Answer 4

All of the planets in our Solar System are pretty much round balls, or spheres. They may be a little squashed due to high speed of rotation.

A planet's odd shape might mean that it was struck by something after it cooled off and became solid. I don't think you will ever see a gas giant planet in any shape other than a sphere.

Answer 5

From August last year one of the criteria for a planet is that is must be spherical. Other planets around other stars that have been discovered are more Jupiter size and larger, but because of the distance most cannot be seen through a telescope. It is assumed that because of the gravity of the planet they will also be spherical

Answer 6

The shape of a celestial body depends on it's size,mass and structural strength.
A body like earth is spherical but with some high mountains.
A more massive body would have greater gravity and if it was similar matter to earth the mountains would not be as high. This applies to any celestial body no matter what it's size.

Answer 7

Gravity. Gravity pulls each and every little thing right into a center ingredient, turning out to be the only shape available, a sphere. If something has adequate mass, it has adequate gravity to pull down all its uneven facets and type a sphere. Asteroids in area are not around because of the fact they have not got adequate gravitational stress to tutor themselves right into a sphere. however the planets are not ideal spheres, they are Oblate Spheroids. meaning the are bulging out on the Equator and somewhat flattened on the poles. this occurs simply by planets rotation. because of the fact the planet rotates particularly speedy centrifugal stress motives the equator to Bulge outwards and the poles to flatten down somewhat.

Answer 8

Gravity tends to pull everything towards itself including the matter planets are made up of. It is also necessary that the matter is equidistant from the centre of gravity so that the planet could revolve with minimal resistance from its gaseous elements...or atmosphere.
Also, planets are basically a huge mass of dust particles being swirled around with such force that they group together very compactly and any odd stick-outs of matter would be smoothed over with time.
Check out "Cosmos-by carl sagan" on youtube. Especially on Planet formation.

Answer 9

They are all spherical-ish, but not spheres.

Some get highly deformed due to asteroids if the planetoid mass is somewhat smaller in size edging towards the masses of large asteroids.

Many asteroids, even large ones, are strangely shaped masses.

Answer 10

Hi. If an object was square then all of the peaks would tend to move towards the center (they would 'fall' down). Your other answers explain why.