Comet Lovejoy (formally designated as C/2014 Q2) was caught partying earlier this year. It was spewing large amounts of ethyl alcohol (same type in alcoholic beverages) and other organic compounds into space according to observations made during its closest approach to the Sun.
Ethyl alcohol was one of 21 different organic molecules discovered in gas from the comet. Glycolaldehyde, a simple sugar, was also detected.
This latest observation is just another piece of evidence hinting at comets as a source of complex organic molecules needed for life to begin.
Comets, like Lovejoy, are ancient pieces left over from the formation of our solar system. Scientists believe they are snapshots of what our solar system looked live shortly after its formation.
Comets usually chill in the orbits that keep them away from the Sun’s heat. But sometimes, a comet gets a nudge closer to the Sun. As the comet gets closer, it heats up and releases gases. Scientists then train telescopes onto the gas to determine what the comet is made up of.
Stefanie Milam, a co-author on the paper and from the NASA’s Goddard Space Flight Center, explains the significance of the Comet Lovejoy observations.
“During the Late Heavy Bombardment about 3.8 billion years ago, when many comets and asteroids were blasting into Earth and we were getting our first oceans, life didn’t have to start with just simple molecules like water, carbon monoxide, and nitrogen. Instead, life had something that was much more sophisticated on a molecular level. We’re finding molecules with multiple carbon atoms. So now you can see where sugars start forming, as well as more complex organics such as amino acids — the building blocks of proteins — or nucleobases, the building blocks of DNA. These can start forming much easier than beginning with molecules with only two or three atoms.”
How astronomers on Earth spot alcohol from Comet Lovejoy
As Comet Lovejoy was releasing 20 tons of water per second in late January, scientists spotted a microwave glow from the comet using a nearly 100-foot diameter radio telescope at Pico Veleta in the Sierra Nevada Mountains of Spain.
As sunlight energizes molecules in Lovejoy’s atmosphere, each one glows at specific microwave frequencies. The IRAM 30-meter telescope (seen above) can identify multiple frequencies at the same time and determine what molecules are being observed and how much.
Organic molecules found in other comets
Remember when the Philae lander bounced off Comet 67P’s surface before eventually landing? The unforeseen bounce actually yielded some science. As Philae first touched down, gas-sniffing instruments Ptolemy and COSAC kicked on. Floating for another two hours, these instruments sampled gas and dust from the comet.
Early results from the COSAC instrument published in late July revealed 16 organic compounds. Four of them – methyl isocyanate, acetone, propionaldehyde and acetamide – were detected for the first time in comets.
Ptolemy detected water vapour, carbon monoxide, carbon dioxide and small amounts of organic compounds including formaldehyde.
There’s still a big question surrounding these observations. “The next step is to see if the organic material being found in comets came from the primordial cloud that formed the solar system or if it was created later on, inside the protoplanetary disk that surrounded the young sun,” said Dominique Bockelée-Morvan from Paris Observatory, a co-author of the paper.