Rocky Planets

A terrestrial planet, telluric planet, or rocky planet, is a planet that is composed primarily of silicate rocks or metals. Within the Solar System, the terrestrial planets accepted by the IAU are the inner planets closest to the Sun: Mercury, Venus, Earth and Mars. Among astronomers who use the geophysical definition of a planet, two or three planetary-mass satellites – Earth's Moon, Io, and sometimes Europa – may also be considered terrestrial planets; and so may be the rocky protoplanet-asteroids Pallas and Vesta. The terms "terrestrial planet" and "telluric planet" are derived from Latin words for Earth, as these planets are, in terms of structure, Earth-like. Terrestrial planets are generally studied by geologists, astronomers, and geophysicists. Terrestrial planets have a solid planetary surface, making them substantially different from the larger gaseous planets, which are composed mostly of some combination of hydrogen, helium, and water existing in various physical states.

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How do rocky planets really form?

Astronomers find the remnants of rocky planets in two stars that evolved into white dwarfs billions of years ago.

An international research team proposes a new theory for the Earth’s formation. It may also show how other rocky planets were formed

Two New Rocky Planets Discovered Close to the Solar System

How NASA's Roman telescope could help find Earth-like planets by surveying space dust. Finding out how much of this material these systems contain would help astronomers learn more about how rocky planets form and guide the search for habitable worlds by future missions.

Massive Rocky Planets Probably Don’t Have big Moons

Moons might not form around rocky planets much larger than Earth

Distant rocky planets may have exotic chemical makeups that don’t resemble Earth’s

After studying the chemical composition of "polluted" white dwarfs, astronomers have concluded that most rocky planets orbiting nearby stars are more diverse and exotic than previously thought, with types of rocks not found anywhere in our Solar System.

Rocky Planets Might Need to be the Right age to Support Life

New Study Reveals Intricate Chemical Link Between Rocky Planets And Their Stars

The Astronomer Who’s About to See the Skies of Other Earths. After the ultra-powerful James Webb Space Telescope launches later this year, Laura Kreidberg will lead two efforts to check the weather on rocky planets orbiting other stars.

Proximity to Sun’s Magnetic Field Determines Composition of Rocky Planets, Study Says