What is the physical difference between a star and a planet?

Answer 1

Stars are made of gas, and generate their own heat and light through fusion.

Planets are made of solids or gases. They may be entirely gaseous, we do not know. (For example, nobody knows if Jupiter has a metallic core or not).

At any rate, the major difference is one of scale: Because stars are huge, they can maintain fusion reactions. Planets are smaller, and therefore can't.

So there's your difference: Stars = fusion, planets = not.

Answer 2

The line between a star and a planet can be hazy, but a simple way to distinguish a star from a planet is a star at least for a brief time generate energy from nuclear reactions, a planet never does. Mass is another differnce, full fledged stars have at least 75 times the mass of Jupiter, a brown dwarf between 13 and 75 Jupiter masses. Stars are mostly or entirely made of plasma, or ionized gasses. Planets are not, though the matter in their interiors is also highly compressed. They have liquid or solid layers in their interoirs, but even a brown dwarf is composed entirely of gasses. A 50 Jupiter mass brown dwarf or a 100 Jupiter mass red-dwarf star can actually be smaller than Jupiter, but much denser than any gas giant planet. Thus the cores of a star are much denser than any planet.

Answer 3

We have two types of planets in out Solar System:
!.) Hard crust planets with solid cores, examples: Mercury,
Venus, Earth, Mars, Pluto.
2.) Gas planets possibly with some metals in their molten cores, examples: Neptune, Jupiter, Uranus.

Stars are bigger than gas giant planets but still mainly composed of gases. There may be some other materials within their cores. These massive objects are huge in comparison to planets and their mass is so huge that the pressure of the mass of gas onto the star's core is intense enough to set of and maintain the nuclear fusion of Hydrogen into Helium. That nuclear fusion is what produces the heat and radiation that we see and feel from the Sun, our star. The surface temperature os our star is 10,000 Degrees F. This differs quite a bit from the surface temperature of planets which ranges from about 850 Degrees F to -400 degrees F., depending upon the planet you are talking about.

The surface of the Sun, oru star, is molten liquid gases. Down below the surface of the Sun, the core temperatures are at several millions of degrees F. A lot of people with years of experience in physics suggest that the molten liquid gases in the core of stars is under such intense heat and pressure that the gases form a metallic like substance which is unknown here on Earth.

Answer 4

A star is an atomic furnace that converts helium atoms to hydrogen atoms through atomic fusion and radiates heat. Planets are satellites of stars and could be either terrestial or gaseous orbs. They do not have the size or mass to turn on like a star.

Answer 5

Stars have to have fusion going on inside them, or at least, they have to be massive enough for fusion to happen without being neutron stars or black holes. Planets have to be too small to have fusion going on inside them. There is another class of objects, 'brown dwarfs', which are not massive enough to be proper stars but still too massive to be proper planets, and which do not fuse anything, but I'm not sure which side they usually get on. One way or the other, the distinctions are a bit fuzzy as there are objects of pretty much all masses out there.

Answer 6

Stars give off their own light and heat energy due to nucelar fusion reactions in their cores and thus makes them visible. Planets cannot generate these temperatures and can only reflect this light to become visible.

Planets are usually much smaller than stars, and are found orbiting stars.

Answer 7

Stars are undergoing fusion of hydrogen into helium, giving off heat and light, while planets don't. Planets are not all alike though, like Jupiter is basically a giant ball of gas, while Mercury is a rock.

Answer 8

The only difference between them is mass. If Jupiter were a bit more massive, it would have sufficient gravity to compress its hydrogen to a point that it would initiate nuclear reactions and thus become a star. Our solar system came very close to being a binary star system. Some refer to Jupiter as a failed star.

Answer 9

Lots of differences, the most obvious physical difference is that a star emits light and a planet only reflects light. Plus all the orbiting information and yadda, yadda, yadda.

Answer 10

Stars are the suns of other solar systems. Suns are made of gases. While planets are made of gas and rock, which rotate around the sun.