Geology of solar terrestrial planets Earth, and Mars) have substantial atmospheres; all have impact craters and tectonic surface features such as rift valleys and volcanoes. The term "inner planet" should not be confused with "inferior planet", which refers to any planet that is closer to the Sun than the observer's planet is, but usually refers to Mercury and Venus. The Solar System is believed to have formed according to the nebular hypothesis, first proposed in 1755 by Immanuel Kant and independently formulated by Pierre-Simon Laplace. This theory holds that 4.6 billion years ago the Solar System formed from the gravitational collapse of a giant molecular
A Beautiful Planet twisted, inverted; you can completely lose your spatial awareness about where you are and what your attitude is, and you can easily get tangled up in that safety tether if you're not cautious. Every single movement you make, you're making an effort to think [things] through." After spending almost the entire film scrutinizing the Earth and the ISS (with its astronauts) in low Earth orbit, one of the final scenes of "A Beautiful Planet" briefly examines an important extrasolar planet (a planet outside of our solar system) which was discovered in 2014. The planet, Kepler-186f, was the first approximately-Earth-sized planet