Within our solar system, few worlds have much in common with Earth. Sure, Venus is about the same size, and Mars may have once (billions of years ago) resembled Earth in terms of its chemistry… But in many ways, Titan, the largest moon of Saturn, seems to be the world most similar to home.

This moon remained a mystery from the time of its discovery in 1655 until the Cassini/Huygens mission managed to peer beneath its veil of thick clouds in 2004. And that mission has made astounding discoveries.

Underneath its obscuring atmosphere, Titan looks shockingly similar to Earth: the lander saw dunes and valleys, as well as beaches and most surprisingly, seas!

We caught the glint of sunlight off these massive methane lakes before, but another near pass by Cassini has allowed us to make a radar map of the topography of Titan’s surface to get a sense of the depth of these alien oceans. It also provided a chance to build upon our understanding of how mountains and valleys here on Earth affect weather patterns around them.

And Cassini has also helped us understand Titan’s unusual atmosphere. A recent NASA press release describes how the moon forms a chemical mix near the surface “like L.A. smog on steroids.” The presence of complex aerosols has long puzzled scientists, but Cassini’s data provided clues to identify the missing link in the process: polycyclic aromatic hydrocarbons (PAHs). (The Academy’s planetarium director recently blogged about a diagram that accompanied that press release.)

Cassini is approaching ten years in orbit around the ringed planet, and its work continues. A future objective is to determine if waves occur on any of Titan’s three largest seas, not too far a stretch given the observations of massive dunes sculpted by wind, but astronomers are still working to piece together the delicate balance of wind, temperature, chemical composition, and viscosity of these alien shores.

Every pass gives us more information about Titan’s clouds and the world beneath them—fleshing out our knowledge of this most familiar-seeming moon.

Josh Roberts is a program presenter and astronomer at the California Academy of Sciences. He also contributes content to Morrison Planetarium productions.

Image: NASA/JPL-Caltech/SSI

Reporting at the AAAS Meeting in Washington DC last week, the multi-disciplinary scientists discussed using radar to look at the aeroecology– the interactions of organisms in the lower atmosphere.

Using “doppler” weather satellites, a biologist like Winifred Frick of UC Santa Cruz is able to track the movement of Brazilian bats in Texas. These bats are important in the agriculture of the area– eating insects that would otherwise be crop pests. Frick stressed that these bats are observable in a cave, but not in-flight– they are too small for transmitters. But with the radar she was able to look at the broad scale migration and the phenological patterns across this particular population.

This information is essential to know as the climate changes because seasonal changes and conditions heavily influence the animals’ behavior. When bats emerge from their caves too early, they risk predation. When they emerge too late, they miss their dinner– the insects. With the radar data, Frick learned in dry conditions bats will emerge sooner, in wet, later.

The technology is incredible. Meteorologists can measure the amount of raindrops in a raincloud and now there’s an algorithm to figure out the amount of bats in a “bat cloud”. The radar can also distinguish between birds, bats and insects. Frick mentioned how she could watch the radar and see a cloud of pink insects fly over a bat cave and then follow a yellow cloud of bats emerge and overtake that pink cloud.

In addition, there is 20 years of data from these radars that the scientists can comb through to look for patterns in different areas for different species.

(Science in Action interviewed Dr. Frick on camera recently about the white nose fungus that is killing bats on the East Coast. Stay tuned for that story.)

Image: W. Frick/Central Coast Bat Research Group; (radar map, inset) SOAR