The Seven Wonders of the Solar System

People like to make lists of things, especially lists of superlatives: the best, fastest, oldest, largest, heaviest and so on. There are lists of the ten fastest animals and the ten longest rivers and even of the ten highest-paid rock stars. The Guinness company created a small industry from publishing lists exactly… » 9/14/14 3:30pm 9/14/14 3:30pm

Iapetus is one of the weirdest moons in the solar system, and one of its weirdest features is its prominent, equatorial mountain range. Now, Popular Science reports on a new theory as to the origins of this peculiar ridge: The mountains, researchers posit in a study recently published in arXiv, fell from spaaaaaaaace. » 4/17/14 5:55pm 4/17/14 5:55pm

The biggest avalanches in the solar system happen on Saturn's moon…

Iapetus, already one of the strangest moons in our solar system, just got a little weirder. Images from the Cassini space mission reveal that the mysterious moon is home to massive ice avalanches second in size only to landslides seen on Mars. Studying them, say researchers, could help us better understand geological… » 7/30/12 7:25am 7/30/12 7:25am

10 Moons Every Person Should Know

Pretty much everyone can rattle off the names of our solar system's eight (formerly nine) planets, but ask the average person to list some moons and you'll be lucky if they can tell you more than two or three. » 3/12/12 12:03pm 3/12/12 12:03pm

How the solar system's strangest moon, Iapetus, lost its rings

One of the weirdest of the solar system's moons is Iapetus. This is a medium-sized (1,471 km (914 miles) satellite of Saturn, orbiting about 3,561,300 km (2,213,000 miles) from the planet. Seen from the surface of Iapetus, Saturn looms about four times larger than a full Moon in Earth's sky. » 1/31/12 4:35pm 1/31/12 4:35pm

Meet Iapetus, Saturn's mysterious "yin-yang" moon

More than 60 moons are known to orbit Saturn, but few of them are as visually striking as Iapetus. Named formally after the Greek mythological Titan, Iapetus is sometimes referred to as the "painted," or "yin-yang" moon, due to puzzling variations in its surface composition. » 1/13/12 5:00pm 1/13/12 5:00pm

Astronomers say Saturn's moon Iapetus may have once had a mini-moon all…

Call it moonception, if you'd like. Astronomers say that a moon-with-a-moon scenario could explain some of the strange features of Iapetus, the third-largest of Saturn's 62-known moons. » 10/17/11 11:18am 10/17/11 11:18am

Iapetus is Saturn's amazing disappearing moon

Of all the hundreds of moons in the solar system, none are weirder than Saturn's satellite Iapetus. We've already talked about its walnut-shaped ridge, but that's nothing compared to the weird optical illusion that lets it disappear from our telescopes. » 3/16/11 5:25pm 3/16/11 5:25pm

The solar system's weirdest moon once had a moon all its own

Saturn's moon Iapetus has a gigantic ridge running along its equator that's twice the height of Mount Everest and covers 75% of the moon's equator. And its existence points to something stranger still: Iapetus once had its very own moon. » 12/14/10 12:10pm 12/14/10 12:10pm

Saturn's Mysterious Splattered Moon

Iapetus may be Saturn's most enigmatic moon, with an unknown dark material splattering most of the surface and a strange ridge that makes one side of the moon resemble a walnut. Astronomers hope the Cassini spacecraft can unlock its mysteries. » 8/10/09 4:00pm 8/10/09 4:00pm