IBM Researchers Use Atomic Force Microscopy To Peer Through Titan's Haze

Scientists are trying to learn all they can about the largest moon orbiting Saturn called Titan. One reason for the scrutiny of Titan is that researchers believe it might hold clues about the early stages of the evolution of life here on Earth. The challenge of studying Titan is that the moon is covered in a hazy atmosphere of brownish-orange fog comprised of organic aerosols.

The nature and origin of that organic aerosol is a mystery. In the laboratory, IBM researchers have discovered new details on how the haze of Titan may have formed and what the chemical makeup might look like. Scientists have resolved molecules of different sizes, giving a snapshot of the different growth stages for the molecules in the haze.

The moon's haze is made of nanoparticles construed of a wide variety of large and complex organic molecules that contain carbon, hydrogen, and nitrogen. The molecules form a cascade of chemical reactions when ultraviolet and cosmic radiation hits a mix of methane, nitrogen, and other gases.

Planetary scientists currently believe that the Earth could've been surrounded by a similar haze about 2.8 billion years ago. Studying the haze around Titan today allow scientists to see what that atmosphere of ancient Earth might've been like. Scientists know about the makeup of the haze around Titan thanks to the Cassini spacecraft that orbited Saturn between 2004 and 2017.

The spacecraft captured direct measurements from the moon's atmosphere, but we still don't understand all the details of Titan's atmosphere. In the lab experiment, the team used a mixture of methane and nitrogen. They then triggered chemical reactions through electric discharge mimicking conditions in the atmosphere of Titan.