can someone tell me what a planet is?

Question

ok here r the guidelines you cant give me a link or a definition from any website (wikipedia) i realize that the IAU is in session about this but i just want your definition of a planet.

Answer 1

and which one are you from?

Answer 2

Until 2005 there was no exact definition of what a planet is. Now, i would define a planet as a body which is larger than the smallest accepted planet Pluto. A planet must also orbit the sun, and it must be large enough so that it's own gravity makes the planet maintain a spherical shape. At present we have a spacecraft en route to Pluto and will be there in 2015. I believe that once we are able to see Pluto close up that Pluto will be declassified as a planet and reclassified as an asteroid. Pluto is also smaller than 7 other moons in our solar system. Not even the Hubble Space telescope can get a clear image of what Pluto looks like.

Answer 3

A nonluminous celestial body larger than an asteroid or comet, illuminated by light from a star, such as the sun, around which it revolves. In the solar system there are nine known planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto.

Answer 4

There is no clear cut Defintion of a "Planet". Rather than try to construct a detailed definition of a planet which is designed to cover all future possibilities, the WGESP (Working Group on Extrasolar Planets) has agreed to restrict itself to developing a working definition applicable to the cases where there already are claimed detections, e.g., the radial velocity surveys of companions to (mostly) solar-type stars, and the imaging surveys for free-floating objects in young star clusters. As new claims are made in the future, the WGESP will weigh their individual merits and circumstances, and will try to fit the new objects into the WGESP definition of a "planet", revising this definition as necessary. This is a gradualist approach with an evolving definition, guided by the observations that will decide all in the end.

Emphasizing again that this is only a working definition, subject to change as we learn more about the census of low-mass companions, the WGESP has agreed to the following statements:

1) Objects with true masses below the limiting mass for thermonuclear fusion of deuterium (currently calculated to be 13 Jupiter masses for objects of solar metallicity) that orbit stars or stellar remnants are "planets" (no matter how they formed). The minimum mass/size required for an extrasolar object to be considered a planet should be the same as that used in our Solar System.

2) Substellar objects with true masses above the limiting mass for thermonuclear fusion of deuterium are "brown dwarfs", no matter how they formed nor where they are located.

3) Free-floating objects in young star clusters with masses below the limiting mass for thermonuclear fusion of deuterium are not "planets", but are "sub-brown dwarfs" (or whatever name is most appropriate).

These statements are a compromise between definitions based purely on the deuterium-burning mass or on the formation mechanism, and as such do not fully satisfy anyone on the WGESP. However, the WGESP agrees that these statements constitute the basis for a reasonable working definition of a "planet" at this time. We can expect this definition to evolve as our knowledge improves.

Answer 5

Planets are heavenly bodies that revolve around the Sun.
There are nine planets in our solar system- Mercury, Venus, Earth,Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. Scientists think that there are other planets in our solar system that are not discovered yet.

Answer 6

A planet is a large, nonluminous celestial body, one of the nine in the solar system, that revolves around a star and often has one or more satellites.

Answer 7

Aside from the obvious, that it revolves around a star, it's probably easier to say what it isn't.
Planets vary greatly in their make up, i.e. Earth, Saturn, and Jupiter are not at all the same.

Answer 8

hmm i would say a planet is a sphere in shape, made up of different atmoshpheres and gases, depending upon the planet. some are environments for lifeforms such as Earth.They are in orbit around the sun. i dunno it's actually kinda hard without looking at a source

Answer 9

a planet is an object that orbits a star and is relatively large in size but smaller than that star.