It's the ultimate scientific mystery.
Scientists at NASA's Jet Propulsion Lab are studying the earliest chemical reactions that may have led to the formation of life on Earth — research, tantalizingly, that could help us figure out if we're alone in the universe.
The researchers combined the earliest known building blocks of life, which date back to roughly four billion years ago, at JPL's Origins and Habitability Lab in a simulation last year.
The scientists are after answering a very intriguing question: "Did Earth’s first life forms create energy with the same chemical reactions used by living organisms today?" a recent JPL blog post on the research reads.
One of the biggest challenges in studying these early processes is simulating an atmosphere that is completely void of oxygen. The element didn't exist in large quantities in our atmosphere until lifeforms capable of producing it in large numbers came along.
Removing all traces of oxygen for an experiment is easier said than done and requires specialized equipment, including an airtight box and filters that can catch any oxygen atoms that may have escaped.
"Science is all about repetition," said JPL research scientist Laurie Barge, who co-leads the Origins and Habitability Lab, in the blog post. "We want to do experiments again and again, and that’s hard to do when you have to spend so much time making sure that not even a tiny bit of oxygen has crept into your test tube."
Another way to study these early processes is to examine other planets or moons that are made up of the same stuff that the Earth was made up of billions of years ago.
"It would be very interesting to validate and check some of our laboratory results against results from another world," said Jessica Weber, who leads the metabolism research at the Origins and Habitability Lab, in the statement.
"Finding an environment like this would help us better re-create early Earth in our lab experiments," she added, "and that would get us closer to answering some of those big questions about life on our own planet and potentially on others."
READ MORE: Removing Traces of Life in Lab Helps NASA Scientists Study Its Origins [JPL]
More on the formation of life: NASA First Look at Japanese Asteroid Samples Reveal the Building Blocks for Life