Hailed as the vacuum cleaner of the Solar System, planet Jupiter plays an important role in facing the maximum comet impacts because of its gravity well and location. The brilliant planet Jupiter dazzles anyone with a clear sky. Roman observers named Jupiter after the patron deity of the Roman state following Greek mythology, which associated it with the supreme god, Zeus. But when Galileo turned his telescope skyward in 1610, Jupiter took on new significance.
Galileo discovered the planet’s four principal moons — and witnessed the first clear observation of celestial motions centered on a body other than Earth. Astronomers recognized Jupiter as the largest planet in the solar system long before any spacecraft provided detailed exploration. The planet’s mammoth size — 88,846 miles (142,984 kilometers) at the equator — holds 2.5 times the mass of all the other planets combined. This makes Jupiter the most dominant body in the solar system after the Sun.
The planet’s mammoth size holds 2.5 times the mass of all the other planets combined.
The planet’s volume is so great that 1,321 Earths could fit inside it. Jupiter is a magnificent example of a gas-giant planet. It has no solid surface and is composed of a small rocky core enclosed in a shell of metallic hydrogen, which is surrounded by liquid hydrogen, which, in turn, is blanketed by hydrogen gas. By count of atoms, the atmosphere is about 90-percent hydrogen and 10-percent helium.
The planet’s volume is so great that 1,321 Earths could fit inside it.
Jupiter’s dominance of the solar system has led to many spacecraft missions, beginning with Pioneer 10’s 1973 flyby. A year later, Pioneer 11 passed the great planet. But sophisticated, close-up study of the giant planet began with the twin flybys of NASA’s Voyagers in 1979. Voyager 1 and 2 increased our jovian knowledge immensely. They mapped the planet’s moons, took detailed images of the Jupiter’s complex atmosphere, and even discovered a faint set of rings.
one of the greatest events in solar system history — Comet Shoemaker-Levy 9’s spectacular crash into the giant planet.
NASA’s Galileo mission, which entered jovian orbit in 1995, gave scientists another windfall. Even as it approached Jupiter in 1994, Galileo witnessed one of the greatest events in solar system history — Comet Shoemaker-Levy 9’s spectacular crash into the giant planet. Galileo sent a probe plummeting into Jupiter’s atmosphere. The probe sampled the atmosphere directly and returned much information before immense pressure deep below Jupiter’s clouds crushed it. Check out this NASA’s video footage and simulation of the Shoemaker-Levi 9 crash on Jupiter.
In 2003, at mission end, Galileo itself met the same fate.
Jupiter’s size and compositional similarity to brown dwarfs and small stars have led some to label it a “failed star.” Had the planet formed with more mass, they claim, Jupiter would have ignited nuclear fusion and the solar system would have been a double-star system.
Life might never have evolved on Earth because the temperature would have been too high and its atmospheric characteristics all wrong. But although Jupiter is large as planets go, it would need to be about 75 times its current mass to ignite nuclear fusion in its core and become a star. Astronomers have found other stars orbited by planets with masses far greater than Jupiter’s. What about sub-stellar brown dwarfs?
Our largest planet still doesn’t come close to these “almost stars.” Astronomers define brown dwarfs as bodies with at least 13 times Jupiter’s mass. At this point, a hydrogen isotope called deuterium can undergo fusion early in a brown dwarf’s life. So, while Jupiter is a planetary giant, its mass falls far short of the mark for considering it a failed star.
Even though it cannot have life, recent studies and discoveries that there could be a possibility that Jupiter’s moon Europa may have presence of life there due to the presence of underground oceans.
-end-
