In the Dust of This Planet: Horror of Philosophy

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The planets were originally thought to have formed in or near their current orbits. This has been questioned during the last 20 years. Currently, many planetary scientists think that the Solar System might have looked very different after its initial formation: several objects at least as massive as Mercury may have been present in the inner Solar System, the outer Solar System may have been much more compact than it is now, and the Kuiper belt may have been much closer to the Sun. [48] Terrestrial planets [ edit ] This model, known as the nebular hypothesis, was first developed in the 18th century by Emanuel Swedenborg, Immanuel Kant, and Pierre-Simon Laplace. Its subsequent development has interwoven a variety of scientific disciplines including astronomy, chemistry, geology, physics, and planetary science. Since the dawn of the Space Age in the 1950s and the discovery of exoplanets in the 1990s, the model has been both challenged and refined to account for new observations. This is still 10–20 times more than the current mass in the main belt, which is now about 0.0005 M Earth. [59] A secondary depletion period that brought the asteroid belt down close to its present mass is thought to have followed when Jupiter and Saturn entered a temporary 2:1 orbital resonance (see below).

The outer planets' orbits are chaotic over longer timescales, with a Lyapunov time in the range of 2–230million years. [102] The formation of the Solar System began about 4.6 billion years ago with the gravitational collapse of a small part of a giant molecular cloud. [1] Most of the collapsing mass collected in the center, forming the Sun, while the rest flattened into a protoplanetary disk out of which the planets, moons, asteroids, and other small Solar System bodies formed. If you insist on including Pluto, it would come after Neptune on the list. Pluto is truly way out there and on a wildly tilted, elliptical orbit (two of the several reasons it was demoted).In all cases, this means that the position of a planet along its orbit ultimately becomes impossible to predict with any certainty (so, for example, the timing of winter and summer becomes uncertain). Still, in some cases, the orbits themselves may change dramatically. Such chaos manifests most strongly as changes in eccentricity, with some planets' orbits becoming significantly more—or less— elliptical. [103] Related: 15 stunning places on Earth that look like they're from another planet Types of planets in the solar system The Exploit: A Theory of Networks, co-authored with Alexander R. Galloway. University of Minnesota Press, 2007. ISBN 978-0816650446.

Main article: Late Heavy Bombardment Meteor Crater in Arizona. Created 50,000 years ago by an impactor about 50 metres (160ft) across, it shows that the accretion of the Solar System is not over. There have been five human-made objects so far, Voyager 1, Voyager 2, New Horizons, Pioneer 10 and Pioneer 11, that have crossed the threshold into interstellar space.Darklife: Negation, Nothingness, and the Will-to-Life in Schopenhauer," Parrhesia no. 12 (2011), p. 3.