terrestrial planet definition of terrestrial planet in the Free Online Encyclopedia.

terrestrial planet, the earth or a planet that resembles the earth in its physical characteristics. The terrestrial planets in the solar system are the earth earth, in geology and astronomy, 3rd planet of the solar system and the 5th largest, the only planet definitely known to support life. Gravitational forces have molded the earth, like all celestial bodies, into a spherical shape.
..... Click the link for more information. , Mercury Mercury, in astronomy, nearest planet to the sun, at a mean distance of 36 million mi (58 million km); its period of revolution is 88 days. Mercury passes through phases similar to those of the moon as it completes each revolution about the sun, although the visible
..... Click the link for more information. , Venus Venus, in astronomy, 2d planet from the sun; it is often called the evening star or morning star and is brighter than any object in the sky except the sun and the moon.
..... Click the link for more information. , and Mars Mars, in astronomy, 4th planet from the sun, with an orbit next in order beyond that of the earth.

Physical Characteristics

Mars has a striking red appearance, and in its most favorable position for viewing, when it is opposite the sun, it is twice
..... Click the link for more information. . These planets are approximately the same size, with the earth the largest. They are considerably denser than the Jovian planets Jovian planets, the planets Jupiter , Saturn , Uranus , and Neptune . They are all larger and more massive than the earth. Since they rotate faster, they are more flattened at the poles than are the terrestrial planets .
..... Click the link for more information. , ranging from a specific gravity of 4 for Mars to 5.5 for the earth. Because they spin less rapidly than the Jovian planets, the terrestrial planets are less flattened at their poles.