Picture an alien. Is it a grey figure with huge eyes, a green tentacled creature with a giant brain or a terrifying scaly monster with sharp teeth and claws?

If we ever meet an alien, we might find that they resembleLook like. us a lot more than we expect. A research project has found that humans might be part alien.

Humans are made up of a complex composition of chemicals, one of which is peptides. When joined together, peptides form proteinsA kind of molecule that drives all biological processes. They make up around one-fifth of our total body mass and without them our bodies could not function. They fold into 3D shapes, making them extraordinarily complicated as a whole., the substances that help our body stay alive.

The new research finds that the matter that makes up space between the stars provides the perfect conditions for peptide creation. 

The peptides that make life possible might have formed in space then arrived on Earth in a meteorA space rock that hits the atmosphere of the Earth. or cometConsisting mainly of dust, ice and gas, comets also orbit the Sun, with tails that can be millions of miles long..

Perhaps this makes us aliens, native to the stars rather than the Earth? The particles that allow us to exist could be older than the formation of Earth. Early lifeforms may have even arrived on Earth already living.

We arguably act like aliens towards our own planet in the way we exploit, reshape and damage it. We have wreakedCaused something to happen in a violent and often uncontrolled way. untold damage on the Earth and used its resources for our own ends.

Others find this idea absurd. There is no firm evidence that we actually came from space particles.

But even if the matter that makes us comes from space, we are creatures of this planet. We are the result of a chain of evolution that takes place only on Earth, and we cannot live in any other known atmosphere.

Are we all aliens?

Yes! We were born in space and to space we will return.

No! We might be made of cosmic particles, but we exist thanks to the combination of resources - air, water, sunlight, soil - that only the Earth provides.

Resemble - Look like.

Proteins - A kind of molecule that drives all biological processes. They make up around one-fifth of our total body mass and without them our bodies could not function. They fold into 3D shapes, making them extraordinarily complicated as a whole.

Meteor - A space rock that hits the atmosphere of the Earth.

Comet - Consisting mainly of dust, ice and gas, comets also orbit the Sun, with tails that can be millions of miles long.

Wreaked - Caused something to happen in a violent and often uncontrolled way.