Jan 13, 2026 · Facts About Jupiter Jupiter is the largest and oldest planet in our solar system. If Jupiter was a hollow shell, 1,000 Earths could fit inside. But the "King of Planets" is no lumbering giant — …

Of the eight planets, Mercury and Venus are the only ones with no moons. The giant planets Jupiter and Saturn lead our solar system’s moon counts. In some ways, the swarms of moons around these …

In Depth Jupiter’s moon Ganymede is proving to be a fascinating world. Not only is it the largest moon in our solar system, bigger than the planet Mercury and the dwarf planet Pluto, but NASA’s Hubble …

Europa orbits Jupiter every 3.5 days and is locked by gravity to Jupiter, so the same hemisphere of the moon always faces the planet. Jupiter takes about 4,333 Earth days (or about 12 Earth years) to …

Oct 21, 2025 · NASA’s real-time science encyclopedia of deep space exploration. Our scientists and far-ranging robots explore the wild frontiers of our solar system.

In the outer solar system, the gas giants Jupiter and Saturn and the ice giants Uranus and Neptune have dozens of moons. As these planets grew in the early solar system, they were able to capture smaller …

Oct 21, 2025 · Europa is one of the largest of Jupiter’s more than 90 moons. It's the sixth-closest moon to the planet.

Jun 26, 2019 · The discovery led to the understanding that planets in our solar system orbit the Sun, instead of our solar system revolving around Earth. Galileo spotted what he thought were bright stars …

Oct 21, 2025 · Mars is the fourth planet from the Sun, and the seventh largest. It’s the only planet we know of inhabited entirely by robots.

According to one well-supported theory, the shifting orbits of the four giant planets (Jupiter, Saturn, Uranus, and Neptune) could have caused most of the original material -- likely 7 to 10 times the …