The “Big Seven” are the largest moons in the solar system, including Ganymede, Titan, Callisto, Io, Moon, Europa, and Triton. They are interesting and unique, with features such as volcanic activity and subsurface oceans. Luna is also unusual, being a large moon compared to the planet it orbits. Four of the Big Seven orbit Jupiter and are named the Galilean moons.
The “Big Seven” refer to the largest moons in the solar system. The Big Seven are larger than all other moons in the solar system by a significant margin. They are, in decreasing order of size: Ganymede (Jupiter), Titan (Saturn), Callisto (Jupiter), Io (Jupiter), Moon (Earth), Europa (Jupiter) and Triton (Neptune). They range in diameter from 2707 km to 5262 km. The eighth largest moon in the solar system is Titania, the largest moon of Uranus, with a diameter of 1578 km.
The Big Seven moons are also among the most interesting moons in the solar system, from volcanic Io, which looks like a sulfur-coated pizza, to Triton, which is believed to be a captured Kuiper belt object. Ganymede is so large that it has its own magnetic field, while Titan is the only moon in the solar system with its own atmosphere. Europa is suspected to have large subsurface oceans with conditions that astronomers have long considered suitable for life.
Despite our close familiarity with it, Luna is also quite unusual. From the point of view of the Earth, it almost perfectly covers the disk of the Sun, which is purely a coincidence. Considering the size of the planet it orbits, the Moon is immense: A similarly sized planet, Mars, has only a couple of small moons, and Venus and Mercury have none at all. For this reason, among other things, the Moon is thought to have formed from the debris of a massive impact, in which a Mars-sized planetoid crashed into Earth and kicked up huge chunks of the crust to form the Moon. Where this planetoid went, no one knows.
Four of the Big Seven orbit the largest planet in the solar system, Jupiter. Originally discovered by Galileo Galilei in 1610 using an early telescope, these are named the Galilean moons in honor of him. They have been extensively studied and photographed in close flybys by numerous space probes. Another probe, Juno, is expected to visit Jupiter in 2016.
Protect your devices with Threat Protection by NordVPN
