"Broccoli, along with other plants and microorganisms, emit gases to help them expel toxins. Scientists believe these gases could provide compelling evidence of life on other planets.
These types of gases are made when organisms add a carbon and three hydrogen atoms to an undesirable chemical element. This process, called methylation, can turn potential toxins into gases that float safely away into the atmosphere. If these gases were to be detected in the atmosphere of another planet using telescopes, they would be suggestive of life somewhere on that planet."