Catch two transits of Io, spot sparkling star clusters, and view Mars at aphelion while the April Full Moon lights the sky ...

Saturn gained a whopping 128 new official moons, as the International Astronomical Union recognised discoveries from a team ...

Callisto lies much farther east, and Io sits alone to Jupiter’s west. By midnight in the Central time zone, Europa has pulled ahead and is just slipping in front of the jovian disk. Ganymede ...

Jupiter's volcanic moon Io doesn't appear to have a subsurface ocean of ... Coupled with similar but smaller gravitational tides from fellow moons Europa, Ganymede and Callisto, it means that a huge ...

But it hasn’t always been this way. Jupiter’s four largest moons – Io, Europa, Ganymede and Callisto – were the first ever discovered orbiting another planet. They were spotted by Galileo ...

But it hasn’t always been this way. Jupiter’s four largest moons – Io, Europa, Ganymede and Callisto – were the first ever discovered orbiting another planet. They were spotted by Galileo ...

The latter will reach Jupiter the following year, performing similar studies of Callisto, Ganymede, and Europa. Since Ganymede and Callisto are farther from Jupiter, they experience less tidal ...

Curious about what planets look like through a telescope? This guide breaks down what you’ll see based on your telescope’s ...