The extra mass of Jupiter compresses its interior to a greater extent than that of Saturn. Why is Saturn almost as big as Jupiter, despite its smaller mass? Jupiter’s greater mass compresses it more, thus increasing its density.

Jupiter’s Great Red Spot makes Earth’s storms look puny by comparison. The Great Red Spot stretches about 1.3 times the size of Earth with winds that can reach maximum speeds of up to 400 miles per hour! The storm has been raging on Jupiter for at least 150 years and possibly as long as 400 years or more.

What would happen to Jupiter if we could somehow double its mass? Its density would increase but its diameter would barely change.

There are three layers of clouds on Jupiter, and each one is composed of different molecules. At one level there are clouds of ammonia, at another level there are clouds made of ammonia and sulfur, and at a third level there are clouds of water (H2O).

Why do the jovian planet interiors differ? Accretion took longer further from the Sun, so the more distant planets formed their cores later and captured less gas from the solar nebula than the closer jovian planets. Different layers represent clouds made of gases that condense at different temperatures.

Uranus

All Jovian planets have rings:

• Jupiter: faint, dusty rings.
• Saturn: bright, spectacular rings.
• Uranus: dark, thin rings.
• Neptune: dark, thin rings & ring arcs.

1) Why do jovian planets bulge around the equator, that is, have a “squashed” appearance? Their rapid rotation flings the mass near the equator outward. The extra mass of Jupiter compresses its interior to a greater extent than that of Saturn.

All four jovian planets have ring systems. Others have smaller, darker ring particles than does Saturn. Why do the jovian planets have rings? They formed from dust created in impacts on moons orbiting those planets.

The atmosphere of Saturn’s largest moon is extremely dense, even thicker than Earth’s atmosphere, and is comprised mainly of nitrogen gas. “The main theory has been that ammonia ice from comets was converted, by impacts or photochemistry, into nitrogen to form Titan’s atmosphere.

153 minutes

Having expended almost every bit of the rocket propellant it carried to Saturn, operators deliberately plunged Cassini into the planet to ensure Saturn’s moons remain pristine for future exploration—in particular, the ice-covered, ocean-bearing moon Enceladus, but also Titan, with its intriguing pre-biotic chemistry.

It was eight years ago on January 14, 2005 that the Huygens spacecraft descended through Titan’s murky atmosphere and touched down – if a bit precariously – by bouncing, sliding and wobbling across the surface of Saturn’s largest moon Titan.

Venus is named for the ancient Roman goddess of love and beauty, who was known as Aphrodite to the Ancient Greeks.

On March 1, 1966 the Venera 3 Soviet space probe crash-landed on Venus, becoming the first spacecraft to reach the surface of another planet. Its sister craft Venera 2 had failed due to overheating shortly before completing its flyby mission.