Today I learned that astronomers from Copenhagen University have found simple sugar molecules floating in the gas around a star some 400 light years away, suggesting the possibility of life on another planets. (Source: x)
The Correlation of Sugar and Life
Sugars are a form of stored energy (like fats and proteins). Thus, theoretically, extraterrestrial life could beak down carbohydrates into simpler molecules in their metabolic processes much like life on earth. In addition, sugars themselves have to be made by life forms (e.g., photosynthesis in plants and gluconeogenesis in humans). So, this entails that there could be life forms out there to harvest as well as make these sugars.
Sugars Far, Far Away
I couldn’t just grasp how we can identify something as small as sugar molecules from so far away. However, with some further internet research, I have learned that molecules such as glycoaldehyde, the sugar in question, can emit electromagnetic radiation of very specific wavelength when they undergo some sort of transition. Many molecules have rotational transitions (where they can drop from a faster spin rate to a slower spin rate), and all of them have vibrational transitions (where a chemical bond or bonds in the molecule drops to a slower vibrational mode).
When a molecule undergoes one of these transitions, it emits a very specific wavelength. Most of the common molecular lines have wavelengths ranging from a centimeter to fractions of a millimeter.
Take a cloud of gas in space, and you’ve eventually got enough molecules emitting these lines that the lines become detectable by terrestrial telescopes like the Atacama Large Millimeter Array, which was used in this detection.
Sorry guys, false alarm. Turns out Neil Armstrong chucked a half-eaten Mars bar out of the Eagle Lander before heading home, and we just found it.