Space Station Info :: Jupiter Exploration

Jupiter Exploration

A number of probes have visited Jupiter.

Pioneer Flyby Missions

Pioneer 10 flew past Jupiter in December of 1973, followed by Pioneer 11 exactly one year later. They provided important new data about Jupiter's magnetosphere, and took some low-resolution photographs of the planet.

Voyager Flyby Missions

Voyager 1 took this photo of the planet Jupiter on January 24, while still more than 25 million miles (40 million kilometres) away. Click image for full caption.
Voyager 1 flew by in March 1979 followed by Voyager 2 in July of the same year. The Voyagers vastly improved our understanding of the Galilean moons and discovered Jupiter's rings. They also took the first close up images of the planet's atmosphere.

Ulysses Flyby Mission

Galileo Mission

Jupiter as seen by the space probe Cassini. This is the most detailed global color portrait of Jupiter ever assembled. There is only one spacecraft to orbit Jupiter and it is the Galileo orbiter, which went into orbit around Jupiter in December 7, 1995. It orbited the planet for over seven years and conducted multiple flybys of all of the Galilean moons and Amalthea .

The spacecraft also witnessed the impact of Comet Shoemaker-Levy 9 into Jupiter as it approached the planet in 1994, giving a unique vantage point for this spectacular event. However, the information gained about the Jovian system from the Galileo mission was limited by the failed deployment of its high-gain radio transmitting antenna. An atmospheric probe was released from the spacecraft in July, 1995.

The probe entered the planet's atmosphere in December 7, 1995. It parachuted through 150 km of the atmosphere, collecting data for 58 minutes, before being crushed by the extreme pressure to which it was subjected. It would have melted and vaporized shortly thereafter. The Galileo orbiter itself experienced a more rapid version of the same fate when it was deliberately steered into the planet on September 21, 2003 at a speed of over 50 km/s, in order to avoid any possibility of it crashing into and possibly contaminating Europa, one of the Jovian moons.

Cassini Flyby Mission

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In 2000, the Cassini probe, en route to Saturn, flew by Jupiter and provided some of the highest-resolution images ever made of the planet.

Overview of Jupiter

Jupiter being the biggest planet is the fifth planet from the Sun and by far the largest within our solar system. Some have described the solar system as consisting of the Sun, Jupiter, and assorted debris, and others describe it as the solar system's vacuum cleaner, due to its immense gravity well. It, and the other gas giants Saturn, Uranus, and Neptune, are sometimes referred to as " Jovian planets."

Jupiter's Moons

Jupiter's 4 Galilean moons, in a composite image comparing their sizes and the size of Jupiter (Great Red Spot visible). From the top they are: Callisto , Ganymede, Europa and Io. Jupiter has at least 63 moons. The four large moons, known as the "Galilean moons", are Io, Europa, Ganymede and Callisto. Ganymade is the largest moon in the solar system.

Classification of Jupiter

There were initially four groups It used to be thought that Jupiter's moons were arranged neatly into four groups of four, but recent discoveries of many new small outer moons have complicated the division; there are now thought to be six main groups, although some are more distinct than others.

Europa , one of Jupiter's many moons.

The inner groups of four small moons all have diameters of less than 200 km, orbit at radii less than 200,000 km, and have orbital inclinations of less than half a degree.

The four Galilean moons were all found by Galileo Galilei , orbit between 400,000 and 2,000,000 km, and include some of the largest moons in the solar system.

Themisto is in a group of its own, and it orbits halfway between the Galilean moons and the next group.

The Himalia group is a tightly clustered group of moons with orbits around 11-12,000,000 km from Jupiter.

Carpo is another isolated case; at the inner edge of the Ananke group, it revolves in the direct sense.

The Ananke group is a collection with rather indistinct borders, averaging 21,276,000 km from Jupiter with an average inclination of 149 degrees.

The Carme group is a fairly distinct group that averages 23,404,000 km from Jupiter with an average inclination of 165 degrees.

The Pasiphae group is a dispersed and only vaguely distinct group that covers all the outermost moons.

It is thought that the groups of smaller moons may each have a common origin, perhaps as a larger moon or captured body that broke up into the existing moons of each group.