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Saturn's natural satellites
Saturn is currently known to have 56 moons, many of which were discovered very recently, and 3 additional un-confirmed, hypothetical moons. However, a precise number of moons can never be given, as ... > more -
Comet Shoemaker-Levy 9
Comet Shoemaker-Levy 9 (SL9, formally designated D/1993 F2) was a comet which collided with Jupiter in 1994, providing the first direct observation of the collision of two solar system ... > more -
Near-Earth object
Near-Earth objects (NEO) are asteroids, comets and large meteoroids whose orbit intersects Earth's orbit and which may therefore pose a collision danger. Due to their size and proximity, NEOs are ... > more -
Solar wind
A solar wind is a stream of charged particles (i.e., a plasma) which are ejected from the upper atmosphere of a star. When originating from stars other than the Earth's Sun, it is sometimes called a ... > more -
Spacecraft propulsion
Spacecraft propulsion is used to change the velocity of spacecraft and artificial satellites, or in short, to provide delta-v. There are many different methods. Each method has drawbacks and ... > more -
Space exploration
Space exploration is the physical exploration of outer space, both by human spaceflights and by robotic spacecraft. While the observation of objects in space—known as astronomy—pre-dates ... > more -
Galaxy formation and evolution
The formation of galaxies is still one of the most active research areas in astrophysics; and, to some extent, this is also true for galaxy evolution. Some ideas, however, are now widely accepted. ... > more
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