Which is the biggest moon in the solar system? A moon is a natural satellite rotating around a planet. While moons vary in size, each moon is much smaller than its planet.
There are 176 known natural moons orbiting planets in our Solar System. 168 moons orbit the “full-size” planets (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune), while 8 moons orbit the smaller planets calling dwarf planets (Ceres, Pluto, Haumea, Makemake, and Eris). Several moons in our solar system are larger than Pluto, and two moons are larger than Mercury. Many people think that the answer to ‘what is the largest moon in the Solar System’ is our Moon. It is not. Our Moon is the fifth largest moon in the solar system. Let’s explore the moons of the solar system. Below are the top 10 largest moons in the solar system.
Oberon is Uranus’ second-largest moon, orbiting at a distance of around 584,000 kilometers. Its orbital period is approximately 13.5 days, coincident with its rotational period. In other words, Oberon is a synchronous satellite, tidally locked, with one face always pointing toward the planet. Composed of roughly half ice and half rock, Oberon has one giant mountain that rises about 6 km off the surface. It was discovered in 1787 by William Herschel. The Uranian system has been studied up close only once the spacecraft Voyager 2 took several images of Oberon in January 1986, allowing 40% of the moon’s surface to be mapped. It has a diameter of 1523 km.
The ninth biggest moon in the existing solar system in terms of size is Rhea. Giotto Domenico Cassini, an Italian-French astronomer, found Rhea in 1672. It is the second-largest moon of Saturn. Rhea is an icy body with a density of about 1.236 g/cm3. The diameter of Rhea is 1528 km. The moon was named after the goddess Rhea in Greek mythology, who was revered as the mother of the gods. On March 6, 2008, NASA announced that Rhea might have a tenuous ring system. It would mark the first discovery of rings about a moon. The first images of Rhea were obtained by Voyager 1 & 2 spacecraft in 1980–1981.
Titania is the largest of the moons of Uranus and the eighth largest moon in the Solar System at a diameter of 1,578 kilometers, an average of 436,000 kilometers from its planet. It takes the moon about 8.7 days to orbit Uranus, and it is in a synchronous orbit with its planet. William Herschel discovered Titania on January 11, 1787. The satellite was named after Titania, a character from William Shakespeare’s A Midsummer Night’s Dream. Uranus is unique in that it is the only planet whose moons were not named after figures from Greek mythology. Instead, they were named after characters from a poem by Alexander Pope and played by William Shakespeare. The moon was not given its current name until 1852 by William Herschel’s son, who suggested names for four of Uranus’ satellites. Scientists believe the moon is about half water ice and half a dense material such as rock. There are fewer craters on Titania than are on Oberon, which tells scientists that Titania is actually the younger moon. Like on Oberon, the surface elements on Titania have been named after characters in works by Shakespeare; all of the physical features are named after female characters. The giant crater on the satellite discovered is Gertrude, named after Hamlet’s mother, approximately 326 kilometers in diameter. The only probe to explore Titania was the Voyager 2, which took many satellite pictures in 1989.
Triton is the largest of Neptune’s 13 moons. British astronomer William Lassell discovered Triton on October 10, 1846, just 17 days after the discovery of Neptune. It was named after the Greek god Triton, who was the son of Poseidon. It is the only large moon in our solar system that orbits in the opposite direction of its planet’s rotation. Triton has a diameter of 2,700 km. Triton is one of the coolest objects in our solar system. It is so cold that most of Triton’s nitrogen is condensed as frost, giving its surface an icy sheen that reflects 70 percent of the sunlight that hits it. Triton is the coldest known object in the Solar System. Its surface temperature averages only -391F (-235C).
Galileo Galilei found Europa in January 1610. Progressively better observations of Europa have occurred over the centuries by Earth-bound telescopes and space probe flybys starting in the 1970s. It is only slightly smaller than our moon. On September 8, 2014, NASA reported finding evidence confirming earlier reports of plate tectonics in Europa’s thick ice shell – the first sign of such geological activity on another world other than Earth. Europa orbits Jupiter in just over 3.5 days, with an orbital radius of about 670,900 km. Europa has a diameter of 3,100 km.
The Moon is Earth’s only natural satellite. Our planet’s trusty companion is an airless, silent world without any signs of life. Because of its small size, the Moon’s force of attraction is too weak to hold the gases it would need to form an atmosphere. The Moon rotates in lockstep with Earth, constantly displaying the same face, with black volcanic maria filling the space between the brilliant old crustal highlands and the notable impact craters on its near side. The Moon is a spherical rocky body, probably with a small metallic core, revolving around Earth in a slightly eccentric orbit at a mean distance of about 384,000 km. Its diameter is 3475 km.
Io is a large, rocky, volcanically active moon of Jupiter. It has a diameter of 3,636 km. Io’s mean distance from Jupiter is 422,000 km. It was discovered in 1610 by Galileo Galilei, along with the other Galilean satellites. Cassini has made further observations–Huygens in 2000 and New Horizons in 2007 and from Earth-based telescopes and the Hubble Space Telescope as technology has advanced. It has the highest density of all the moons and is the driest known object in the Solar System. It was named after the mythological character Io, a priestess of Hera who became one of Zeus’s lovers.
With a diameter of over 4,800 km, Callisto is the third largest satellite in the solar system and almost Mercury’s size. It was discovered in 1610 by Galileo Galilei. Callisto is the outermost of the Galilean satellites (Ganymede, Europa, Io, Callisto). Callisto is named for the beautiful daughter of Lycaon, who followed the chaste goddess of the hunt, Artemis. Unfortunately, since Callisto was seduced by Zeus (the Greek equivalent of the Roman god Jupiter) and became pregnant, she was banished by Artemis. Zeus changed Callisto into a bear to protect her from Hera’s jealousy. Later, Zeus placed Callisto and their son in the sky and mother and son.
Titan is Saturn’s largest moon and the second largest in the solar system. On March 25, 1655, it was discovered by the Dutch astronomer Christiaan Huygens. Titan is the only natural satellite known to have a dense atmosphere. Titan’s atmosphere is active and complex, and it is mainly composed of nitrogen (95 percent) and methane (5 percent). Titan also has a presence of organic molecules that contain carbon and hydrogen, often including oxygen and other elements similar to what is found in Earth’s atmosphere and that are essential for life. It has a diameter of 5,152 km.
Ganymede is a satellite of Jupiter and the largest satellite in our solar system. Interesting and fun facts about Ganymede, it is more significant than Mercury and Pluto and three-quarters the size of Mars. It has a diameter of 5,268 km. It is orbiting at about 1.070 million km and takes about seven Earth days to orbit Jupiter. Ganymede is composed of approximately equal amounts of silicate rock and water ice. It is a fully differentiated body with an iron-rich, liquid core, and it might have ice and oceans stacked up in several layers. Galileo Galilei uncovered Ganymede on January 7, 1610. Along with three other Jovian moons, the discovery was the first time a moon was discovered orbiting a planet other than Earth. Galileo’s discovery eventually led to the understanding that planets orbit the sun instead of our solar system revolving around Earth. Galileo called this moon Jupiter III. When the numerical naming system was abandoned in the mid-1800s, the moon was named after Ganymede, a Trojan prince in Greek mythology. Zeus, a counterpart of Jupiter in Roman mythology, carried Ganymede, who had taken the form of an eagle, to Olympus, where he became a cupbearer to the Olympian gods and one of Zeus’ lovers.