Why do Jupiter’s large moons outnumber Saturn’s?

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Why do Jupiter’s large moons outnumber Saturn’s?

Jupiter's large moons - Ganymede, Callisto, Io and Europa - number four. But Saturn has just one large moon, Titan. Why? It may be the planets' magnetic fields.

Paul Scott Anderson

April 12, 2026

Supermassive black holes could merge in 100 years

For the first time, astronomers have direct evidence of a close pair of supermassive black holes in a galaxy. These black holes could merge in 100 years.

EarthSky Voices

April 10, 2026

The Year Without a Summer: The chaos of 1816

1816 was The Year Without a Summer, following the eruption of Tambora in 1815. The haze was so thick, people could see sunspots with their eyes alone.

Kelly Kizer Whitt

April 10, 2026

Looking for sky almanacs? EarthSky recommends …

Here are some almanacs that show you the rising and setting times for the sun, moon, planets and satellites in your sky.

Bruce McClure

April 10, 2026

Native Americans played dice more than 12,000 years ago

Native Americans played dice games more than 12,000 years ago. That's 6,500 years earlier than Bronze age people in the Old World did.

Shireen Gonzaga

April 9, 2026

Pareidolia is seeing things like faces in random objects

Seeing things such as a creepy face in satellite imagery is called pareidolia. Now, a new study says we're more likely to see angry men in random objects.

Editors of EarthSky

April 9, 2026

What is the Earth’s most distant spacecraft?

The most distant spacecraft from Earth is Voyager 1. Launched in 1977, Voyager 1 is a few billion miles farther from Earth than its sibling, Voyager 2.

Editors of EarthSky

April 9, 2026