Titan, rich in organic matter, has long been one of the targets for the exploration of extraterrestrial life, but a new study published in the American Journal of Planetary Science estimates that even if life exists, the total amount of life on Titan could be surprisingly small — the entire planet's microbes combined weigh as much as a puppy. This discovery provides a new dimension for human exploration of extraterrestrial life.

Titan (also known as Titan) is Saturn's largest moon and the only planetary moon in the solar system with a thick atmosphere. Titan's surface is dotted with rivers, lakes, icy boulders, and soot-shaped "sand dunes" formed by liquid methane, and its geomorphological features are similar to those of the early Earth, while the ice crust hides an ocean of liquid water, making it one of the most striking objects in the solar system.

A team of researchers from the University of Arizona and other institutions in the United States further evaluated the evidence for the existence of life on Titan by analyzing the relevant biological metabolic processes.

Using bioenergetics modeling, they focused on the transport and utilization of glycine, the simplest amino acid on Titan. Titan's atmosphere synthesizes large amounts of organic matter, including amino acids, and it is theorized that microorganisms in the oceans beneath the ice crust need a steady supply of these organic substances. However, only a small fraction of organic matter can enter the ocean through temporary waterways created by meteorite impacts.

Model calculations show that such a small supply of organic matter can only support the growth of microorganisms for a maximum of a few kilograms, which weighs only as much as a puppy.

The researchers believe that this finding not only suggests that NASA's planned Titan exploration program needs to adjust its strategy to find life, but also means that the presence of abundant organic matter may not be the same as habitability.

Comprehensive Xinhua News Agency and other reports