Acetylene and hydrogen molecules are disappearing from the atmosphere of Saturn's moon, Titan.
It's a mystery befitting Sherlock Holmes' investigative skills, a mystery NASA scientists hope to crack.
Saturn's Largest Satellite
About fifty percent larger than Earth's moon, Titan is Saturn's largest satellite and the only moon with an atmosphere.
It has long been known for its methane- and ethane-rich atmosphere, and has intrigued scientists when they discovered lakes of liquid methane on its surface.
Titan is a frigid place, with temperatures hovering around minus three hundred degrees Fahrenheit, but despite the cold, scientists wonder if Titan may harbor life.
Carbon Based Life
Life as we know it on Earth is carbon based, and Titan has the same hydrocarbon building blocks for living organisms. But, can life exist at such low temperatures, and if it does, can we detect its presence? Missing molecules may be our first clue.
Hydrogen molecules should be produced when ultraviolet light breaks down methane and acetylene molecules in Titan's atmosphere.
Some hydrogen is lost to space, but observations from the Cassini spacecraft don't see build up near the surface as expected.
Likewise, methane is converted into acetylene or benzene molecules which sink to the surface. Lots of benzene has been found, but acetylene is mysteriously missing.
So What's Happening To The Hydrogen And Acetylene?
Scientists say something must be converting them back into methane. But they are not sure what.
An unknown catalyst, perhaps? Another intriguing possibility is that some bacteria like organisms are using the molecules for energy.
Scientists are going to need more than a magnifying glass to solve this mystery. They hope to send a probe to Titan with instruments to test for living organisms.
Only then will we know for sure.