Scientists may have found protein, one of the building blocks of life, inside a meteorite that spent potentially millions of years hurtling through the cold vacuum of space.
The first-time discovery, if confirmed, could have profound implications for our understanding of how, and where, life comes from—and could add a wrinkle to humanity’s widening hunt for extraterrestrial life.
If the meteorite did indeed arrive on Earth with a payload of protein, it could bolster the notion that life—or at least the processes that result in life—could exist across the vast expanse of the universe and not just on our planet.
“Protein is a good indicator of possible life,” Gilbert Levin, a former NASA scientist who helped to lead an early search for life on Mars, told The Daily Beast.
But experts warn that there are still more questions than answers as far as the possible space-protein is concerned. It’s way too soon to celebrate a major breakthrough.
A team of researchers from Harvard University, superconductor firm Plex Corporation, and science-supplier Bruker Scientific found evidence of a protein inside of a meteorite that plummeted to Earth in what is now Algeria.
Proteins are the “workhorse molecules of life,” to borrow NASA’s phrasing. They form the structure of organic tissue and make up the enzymes that regulate chemical reactions in living bodies.
The team revealed its findings in a paper that it first posted online in late February. The highly-technical, 33-page paper describes what is, in essence, a simple process of discovery.
Harvard’s Julie McGeoch and her colleagues used tiny, sanitized tools to drill into the meteorite and collect powder from deep inside the rock.
They then mixed the powder in various liquids, including water and chloroform. The team fired a laser into the liquid suspensions, turning them into gases. Finally, the scientists applied a process called “mass spectrometry,” bombarding the samples with electrons in order to break up the molecules and make them easier to analyze.
What they found, if real, could change our conception of life’s origins. Deep inside the meteorite resided a so-called “hemolithin protein” made up mostly of glycine and amino acids. It also had “caps” at both ends composed of oxygen, lithium and iron, a unique arrangement that no one has ever seen before on protein.
The unconfirmed discovery builds on years of earlier work. In 2004, NASA flew its Stardust probe through the atmosphere of the Wild 2 comet two billion miles from Earth.
The probe deployed a sponge-like material to soak up the comet’s gases and dust. The probe jettisoned the samples back to Earth, where scientists spent years analyzing them.
In 2009, NASA announced the major findings. The agency had found, in the Wild 2 samples, an amino acid called glycine, which living organisms use to make proteins.
“The discovery of glycine in a comet supports the idea that the fundamental building blocks of life are prevalent in space, and strengthens the argument that life in the universe may be common rather than rare,” said Carl Pilcher, director of the NASA Astrobiology Institute in California.
The Harvard team’s space-protein could underscore NASA’s earlier discovery and fuel further efforts to probe deep space for signs of life. NASA is already looking for evidence of life on Mars and is organizing a mission to Jupiter’s moon Europa to extend the search. Enceladus, a moon of Saturn, is another top target.
But experts advise caution. The Harvard team’s paper is still awaiting peer review. For that reason, the team and several outside experts declined to discuss the possible protein discovery with The Daily Beast.
John Rummel, a scientist with the California-based SETI Institute, which analyzes space signals for evidence of alien communication, told The Daily Beast the protein in the Algerian meteorite could have crept into the space rock after it landed on Earth.
The Harvard team claimed in their paper that they found isotopes in the protein pointing to an extraterrestrial origin, but Rummel said he wasn’t convinced. He cited a French study finding that meteorites hitting the desert can pick up Earth contaminants after just 24 hours in the sand.
The Harvard team members and other scientists promised to open up about the possible protein discovery after more researchers get a chance to review the initial findings. If the Algerian meteorite’s protein payload does indeed change our conception of life, it won’t happen overnight.
And even if the current protein discovery fizzles, the effort behind it could lead to other important findings in the future, Rummel said. “I am hoping that the analytical techniques and the work of this group will continue.”