Watch this video about other moons in our solar system! Moogega Stricker. We on Earth have just one moon, but some planets have dozens of them. Up first are Mercury and Venus. Neither of them has a moon. Any moon would most likely crash into Mercury or maybe go into orbit around the Sun and eventually get pulled into it.
Mars has two moons. Their names are Phobos and Deimos. Next are the giant outer planets. Saturn, Uranus and Neptune also have some irregular moons, which orbit far from their respective planets. Saturn has two ocean moons — Enceladus and Titan. Both have subsurface oceans and Titan also has surface seas of lakes of ethane and methane.
The chunks of ice and rock in Saturn's rings and the particles in the rings of the other outer planets are not considered moons, yet embedded in Saturn's rings are distinct moons or moonlets.
These shepherd moons help keep the rings in line. Titan, the second largest in the solar system, is the only moon with a thick atmosphere. In the realm of the ice giants, Uranus's inner moons appear to be about half water ice and half rock. Miranda is the most unusual; its chopped-up appearance shows the scars of impacts of large rocky bodies. Neptune's moon Triton is as big as Pluto and orbits backwards compared with Neptune's direction of rotation.
Pluto's large moon Charon is about half the size of Pluto. Like Earth's Moon, Charon may have formed from debris resulting from an early collision of an impactor with Pluto.
Scientists using the Hubble Space Telescope to study Pluto found four more small moons. Eris, another dwarf planet even more distant than Pluto, has a small moon of its own, named Dysnomia. Haumea, another dwarf planet, has two satellites, Hi'iaka and Namaka.
Ceres, the closest dwarf planet to the Sun, has no moons. Scientists weren't sure if asteroids could hold moons in their orbits until the Galileo spacecraft flew past asteroid Ida in Images revealed a tiny moon, later named Dactyl. Read More. The next full Moon is the Beaver Moon, and there will be a near-total lunar eclipse. Full Moon Guide: November - December Terrestrial planets also have a molten heavy-metal core, few moons and topological features such as valleys, volcanoes and craters.
In our solar system , there are four terrestrial planets, which also happen to be the four closest to the sun: Mercury, Venus, Earth and Mars. During the formation of the solar system , there were likely more terrestrial planetoids, but they either merged with each other or were destroyed. The definition of "planet" from the International Astronomical Union is controversial. The IAU defines a planet as a celestial body that is in orbit around the sun, has a nearly round shape, and has mostly cleared its orbital neighborhood of debris.
Scientists are divided in particular on the third point , with some saying that it's hard to define how much clearing a planet does, while others saying a world like Pluto would clear less than a world like Earth.
This means that some astronomers argue that the dwarf planet Pluto should be classified as a planet, along with various other dwarf planets scattered throughout the solar system. Mercury is the smallest terrestrial planet in the solar system, about a third the size of Earth.
It has a thin atmosphere, which causes it to swing between burning and freezing temperatures. Mercury is also a dense planet, composed mostly of iron and nickel with an iron core. Its magnetic field is only about 1 percent that of Earth's, and the planet has no known moons.
The surface of Mercury has many deep craters and is covered by a thin layer of tiny particle silicates. In , scientists found extensive evidence of organics — the building blocks of life — as well as water ice in craters shaded from the sun. Mercury's thin atmosphere and close proximity to the sun mean it's impossible for the planet to host life as we know it. Venus , which is about the same size as Earth, has a thick, toxic carbon-monoxide-dominated atmosphere that traps heat, making it the hottest planet in the solar system.
Venus has no known moons. Much of the planet's surface is marked with volcanoes and deep canyons. The biggest canyon on Venus stretches across the surface for 4, miles nearly 6, kilometers.
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