Comets may reveal secrets of search for life in outer space

For a planet to sustain life, it must have organic matter made up of the elements carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur. It is these elements that combine to create the organic molecules necessary for life on Earth and other planets.

But how were these elements transported to the planets?

According to historical theories, Earth was bombarded by asteroids, comets, and other cosmic objects. Some believe that comets are the “best candidates” to bring water and the molecules necessary for life to form on Earth.

Now, experts at the University of Cambridge's Institute of Astronomy have discovered that comets can do the same for distant exoplanets.

To decipher the mystery, experts developed mathematical models that theoretically demonstrate that comets could provide the building blocks of life to exoplanets.

According to the team of experts, comets contain many types of molecules necessary for life, but they only distribute these molecules to planets under certain circumstances.

They believe that if the comet moves slowly enough, at less than 15 km/s, when it hits the planet's surface, it will bring back intact life molecules.

If the comet moves faster than this, the essential molecules will not survive when it hits the planet, because the high speed and heat produced during the collision will cause them to break apart.

The ideal place for a slow-moving comet to easily preserve life molecules is a system of low-mass exoplanets orbiting a host star like the Sun.

In such a system, the comet could be attracted by the gravity of the exoplanets, weaving through the exoplanets' orbits, causing it to slow down before colliding.