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 seven largest natural satellites in the Solar System (those bigger than 2,500 km across) are Jupiter's Galilean moons (Ganymede, Callisto, Io, and Europa), Saturn's moon Titan, Earth's moon, and Neptune's captured natural satellite Triton. Triton, the smallest of these, has more mass than all smaller natural satellites together.
The known icy moons in this range are all ellipsoidal (except Proteus), but trans-Neptunian objects up to 450–500 km radius may be quite porous. [10] For simplicity and comparative purposes, the values are manually calculated assuming that the bodies are all spheres. The size of solid bodies does not include an object's atmosphere.
The Earth's only natural satellite, the Moon is the brightest object in the sky after the Sun. The first full moon of 2024 will rise on Jan. 25 at 12:54 p.m. EST. Traditionally known as the Wolf ...
The Galilean moons are named after Galileo Galilei, who observed them in either December 1609 or January 1610, and recognized them as satellites of Jupiter in March 1610; [2] they remained the only known moons of Jupiter until the discovery of the fifth largest moon of Jupiter Amalthea in 1892. [3]
Trojan moons Calypso and Telesto (trojans of Tethys), and Helene and Polydeuces (trojans of Dione). These small moons share their orbits with Tethys and Dione, leading or trailing either. [180] [181] Outer large satellites Rhea, Titan, Hyperion, and Iapetus. [179] Titan is the only satellite in the Solar System to have a substantial atmosphere ...
For Earth this means a period of just under 12 hours at an altitude of approximately 20,200 km (12,544.2 miles) if the orbit is circular. [16] Molniya orbit: A semi-synchronous variation of a Tundra orbit. For Earth this means an orbital period of just under 12 hours. Such a satellite spends most of its time over two designated areas of the ...
The Roman numbering system for satellites arose with the very first discovery of natural satellites other than Earth's Moon: Galileo referred to the Galilean moons as I through IV (counting from Jupiter outward), refusing to adopt the names proposed by his rival Simon Marius. Similar numbering schemes naturally arose with the discovery of ...