Cassini space probe images a cloudy summer day on Saturn's largest moon

By observing clouds develop on other planets, scientists may glean new insights into those planets’ dynamic behavior and chemical makeup.

First Look

What does a cloudy summer day look like on Titan? As it turns out, not much like the ones on Earth.

On Friday, NASA released a time-lapse video showing methane clouds swirling around the northernmost region of Saturn’s largest moon. The footage was captured by the space agency’s Cassini spacecraft in late October.

Time-lapse videos can help researchers tell the difference between noise caused by cosmic rays and actual weather conditions. And by observing developing clouds on other planets, scientists can glean new insights about those planets’ dynamic behavior and chemical makeup.

To produce this video, Cassini snapped a photo of Titan’s atmosphere once every 20 minutes for 11 hours. Over the course of the footage, several sets of clouds can be seen developing and fading. NASA reported in a press release:

Most prominent are long cloud streaks that lie between 49 and 55 degrees north latitude. While the general region of cloud activity is persistent over the course of the observation, individual streaks appear to develop then fade. These clouds are measured to move at a speed of about 14 to 22 miles per hour (7 to 10 meters per second).

Previous climate models of Titan predicted moderate-to-high cloud activity in the north during early summer. But Cassini has observed far less, which suggests that our current understanding of the moon’s seasonal weather and climate is incorrect or incomplete.

Over the course of its commission, Cassini has provided a wealth of information about Saturn and its satellites. The probe, which launched in 1997 and arrived in 2004, has even observed geological features that may remind us of home.

In September, it pinged back photos of linear sand dunes on Titan – not unlike the ones found on Earth’s Sahara Desert, except that the moon’s sand was made of grainy hydrocarbons instead of silicates.

In August, researchers used Cassini’s radar images to confirm that flowing liquid methane had carved deep canyons into Titan’s surface. The Christian Science Monitor’s Ben Rosen reported:

The canyons’ depth and steepness show the process that created them occurred over a long period of time or eroded the canyons’ surfaces much faster than other parts of Titan. This could have occurred because the terrain was once at a high elevation (like the process that formed the Grand Canyon), or quickly dropped to the moon’s sea level (like the process that formed Arizona’s Lake Powell).

That same liquid methane may even make a primordial soup, researchers say. Though there is not yet any data to support or refute the theory, Titan’s methane oceans – combined with a nitrogenous atmosphere and sunlight – could theoretically contain the right “prebiotic conditions” to support life forms, according to a July study.