The Milky Way is full of toxic, grease-like molecules, according to astronomers from Australia's University of New South Wales (UNSW) and Turkey's Ege University.
To estimate the amount of "space grease" in the galaxy, scientists manufactured material with the same properties as the interstellar dust that exists in the regions between stars for a study published in the journal Monthly Notices of the Royal Astronomical Society. This dust is partly made up of a carbon-based, grease-like substance, along with other substances.
The scientists wanted to address the question of how much organic material—substances that contain carbon and are essential for life—exists in interstellar space, something that has long been unclear. Only half of the carbon expected to exist in these regions is found in its purest form. The rest is chemically bound with hydrogen either in a grease-like form (aliphatic carbon) or a gaseous version (aromatic carbon).
In a lab, the researchers recreated the process by which organic molecules are produced by carbon stars—stars that contain more carbon than oxygen. They then analyzed the resulting material to determine the amount of aliphatic, or grease-like carbon, that was produced.
"Combining our lab results with observations from astronomical observatories allows us to measure the amount of aliphatic carbon between us and the stars," Tim Schmidt, from UNSW's School of Chemistry, said in a statement.
The results showed that there roughly 100 greasy carbon atoms for every million hydrogen atoms. This accounts for between a quarter and a half of all the carbon in interstellar space. Using this ratio, the scientists calculated that in the Milky Way there is an estimated 10 billion trillion trillion tons of space grease, or enough for 40 trillion trillion trillion packs of butter.
The grease is certainly not edible, however. "This space grease is not the kind of thing you'd want to spread on a slice of toast!" Schmidt said. "It's dirty, likely toxic and only forms in the environment of interstellar space—and our laboratory. It's also intriguing that organic material of this kind—material that gets incorporated into planetary systems—is so abundant."
The researchers now want to find out what the abundance of aromatic carbon is. Together with the latest findings, this will enable scientists to understand how much of this element is available to create life.
