Search results
Results from the WOW.Com Content Network
Of the Solar System's eight planets and its nine most likely dwarf planets, six planets and seven dwarf planets are known to be orbited by at least 300 natural satellites, or moons. At least 19 of them are large enough to be gravitationally rounded; of these, all are covered by a crust of ice except for Earth's Moon and Jupiter's Io. [1]
The first known natural satellite was the Moon, but it was considered a "planet" until Copernicus' introduction of De revolutionibus orbium coelestium in 1543. Until the discovery of the Galilean satellites in 1610 there was no opportunity for referring to such objects as a class.
For example, if a TNO is incorrectly assumed to have a mass of 3.59 × 10 20 kg based on a radius of 350 km with a density of 2 g/cm 3 but is later discovered to have a radius of only 175 km with a density of 0.5 g/cm 3, its true mass would be only 1.12 × 10 19 kg.
The satellites of Mars include : Non functional but (probably) orbiting: Viking 1 & 2 orbiter; Mariner 9; Mars Global Surveyor; Mars 2, 3, 5; Phobos 2;
Several factors make placing a spacecraft into an areostationary orbit more difficult than a geostationary orbit. Since the areostationary orbit lies between Mars's two natural satellites, Phobos (semi-major axis: 9,376 km) and Deimos (semi-major axis: 23,463 km), any satellites in the orbit will suffer increased orbital station keeping costs due to unwanted orbital resonance effects.
It is projected that parameters for surface habitats will be comparable to those of terrestrial planets like Earth and Mars, namely stellar properties, orbit, planetary mass, atmosphere and geology. Of the natural satellites in the Solar System's habitable zone – the Moon , two Martian satellites (though some estimates put those outside it ...
From a circular orbit, thrust applied in a direction opposite to the satellite's motion changes the orbit to an elliptical one; the satellite will descend and reach the lowest orbital point (the periapse) at 180 degrees away from the firing point; then it will ascend back. The period of the resultant orbit will be less than that of the original ...
The Sun, a spectral class G2V main-sequence star; The inner Solar System and the terrestrial planets. 2021 PH27; Mercury. Mercury-crossing minor planets; Venus. Venus-crossing minor planets. 524522 Zoozve, Venus' quasi-satellite; Earth. Moon; Near-Earth asteroids (including 99942 Apophis) Earth trojan (2010 TK 7) Earth-crosser asteroids. Earth ...