A team of scientists just discovered the longest organic molecules yet seen on Mars, the fourth planet from the Sun and and a tantalizing venue for humankind’s search for life beyond Earth.

While the presence of these molecules is not proof of ancient life on Mars, scientists say it shows we could detect chemical signatures of past life, if it ever existed.

The Mars Curiosity rover’s onboard mini-lab has helped confirm the existence of the largest organic molecules ever found on the Red Planet. The trio of long-chain compounds preserved in Martian soil are believed to be the remnants of prebiotic components required for life to develop on Earth.