Could The Joker Really Appear On Gotham This Season!?

Check out new Avengers: Age of Ultron pics. Another geek icon joins AKA Jessica Jones. Freddie Prinze Jr. talks about Star Wars: Rebels' second season. Plus glimpses of Inside Out, Seventh Son, Minions and Person of Interest, and what's next for Sleepy Hollow, Once Upon a Time and Defiance. Behold, Spoilers! » 2/03/15 6:00am 2/03/15 6:00am

Astronomers Capture A Rare Glimpse Of Eclipsing Jovian Moons

Earlier this month, astronomers surveying Jupiter's moon Io received an early Christmas surprise when another Jovian moon, Europa, unexpectedly passed in front of it. » 12/29/14 9:30am 12/29/14 9:30am

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

Weather Channel Reporter Won't Stop Mispronouncing This Moon's Name

Earlier this week, The Weather Channel's Matt Sampson hosted an interesting little news segment about violent volcanic activity recently detected on Jupiter's moon Io. But Sampson didn't call the planet by its name, which is pronounced "eye-oh." Instead, he – well, we don't want to spoil it. [Warning: Video Autoplays] » 8/10/14 4:30pm 8/10/14 4:30pm

I could watch this time-lapse of Jupiter (and Io) all day long

A redditor by the name of bubbleweed shot this time-lapse of Jupiter moving in relation to its moon, Io, over the course of five and a half hours, and boy howdy is it beautiful. » 1/11/14 2:00pm 1/11/14 2:00pm

Alien life in our solar system, according to pulp-art legend Frank R.…

Almost fifty years after his death, Frank R. Paul remains one of the biggest names in science fiction art and pulp magazine illustration. These visions of life on moons and planets throughout our solar system (recently posted to reddit with no attribution to Paul, his work, or his impact) provide us with another… » 4/08/13 3:20pm 4/08/13 3:20pm

How Someone Measured the Speed of Light by Accident

At a time when many thought the Speed of Light was infinite, a few brave souls tried to come up with a definite number for it. Most of them failed. There was one guy, however, who wasn't even trying, but came up with a great way to guess. Take a look at how he took his measurement, and what it has to do with the moons… » 12/13/12 4:00pm 12/13/12 4:00pm

Experience one (spectacular) day in orbit around Jupiter

Io keeps the same face toward Jupiter as it orbits the planet. For this reason, Jupiter appears to hang motionless in Io's sky. Just as the Earth's Moon does, Jupiter goes through phases as Io orbits it. Here's a gallery showing the view from a location in the northern hemisphere during the course of a single day.… » 5/14/12 3:29pm 5/14/12 3:29pm

A breathtaking reminder of just how gigantic Jupiter really is

If you're looking for a reminder of how impossibly huge Jupiter is, just take a gander at this image from Cassini. That tiny satellite in front is Io...which is almost the same size and relative distance as our own Moon. » 4/08/12 11:00am 4/08/12 11:00am

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

The weirdest moons in the solar system, and what it would look like to…

It would sometimes seem as though there are two solar systems: One including planets, and another including moons. Until recently, most books about the solar system focused on the planets, stopping only to acknowledge the existence of their satellites with a kind of half-embarrassed nod. They would be discussed as a… » 11/10/11 8:00am 11/10/11 8:00am

Sulfur volcanoes erupt on Jupiter's moon Io

The moon Io is home to over 400 active volcanoes, making it the most geologically active place in the solar system. And in this image created from the Galileo probe, you can see two huge volcanoes erupting from the surface. » 5/22/11 9:00am 5/22/11 9:00am

Beneath the surface of Jupiter's moon Io, there is an ocean of magma…

Jupiter's moon Io is a hotbed of geological activity, with over 400 active volcanoes. Because of this high level of activity, scientists have been debating for years about what's going on under the moon's surface. Now we know. » 5/12/11 11:26am 5/12/11 11:26am

The Rough Guide to Solar System Mountaineering

The great challenge for any climber is to conquer each continent's tallest mountain. But tomorrow's climbers can consider a far more extreme challenge: leaving Earth to climb the tallest peaks of the solar system. Here's how they'll do it. » 10/01/10 9:30am 10/01/10 9:30am

Jupiter's Explosive Moon Io Built Its Atmosphere Out of Frozen Volcano…

At last, a decades-old mystery has been solved about the atmosphere on Jupiter's volcano-riffic moon Io. This moon, whose super-lavalicious geological situation has earned it the titles "pizza face" and "most volcanically active body in the solar system," is special to the heart of io9 because we love fire. Turns out… » 10/15/07 6:16pm 10/15/07 6:16pm