Planets and stars differ in their mass, composition and life cycle. Stars are usually structurally simple bodies of high mass that produce energy by way of nuclear fusion of hydrogen into helium. Planets are much smaller, do not generate light and usually orbit stars.Know More
Solar systems form when clouds of gas and dust coalesce into protostellar accretion disks. Most of the mass in such a disk falls toward the center, which provides the mass and energy required to drive the nuclear fusion engine that powers a star throughout its life. Outside the star, small eddies in the accretion disk collapse locally to form small bodies. These small objects grow in size as they collide with one another over millions of years. The largest of these bodies become planets.
Unlike stars, planets can be gaseous or rocky. Some worlds, such as the dwarf planet Pluto, incorporate ice as a major component of their makeup. At the lower size range, dwarf planets can resemble comets, which are formed in ways similar to planets. The largest possible planet would have a mass 75 times that of Jupiter. Above that threshold, the world's mass is sufficient to sustain fusion, and it is, by definition, considered a brown dwarf star.Learn more about Planets
NASA states that for an astronomical body to be considered a moon, that object must orbit a planet. For a planet to be classified as such, it must meet certain strict criteria set by the International Astronomical Union.Full Answer >
The planet Mercury was named by ancient Romans after their messenger god and the god of travelers, Mercury. They believed that their messenger god, Mercury, had wings on his shoes and could fly quickly from one place to another.Full Answer >
The planet Saturn is named after Saturnus, an ancient Roman god associated with agriculture, wealth and liberation. It is the sixth planet from the Sun and second only in size to Jupiter. This size makes it visible to the naked eye.Full Answer >
There is no evidence of life existing on Venus, and current scientific theories suggest that it is very unlikely that the planet can support life. The planet's high temperature and lack of water are cited as reasons for its hostility to harboring life.Full Answer >