This snakelike gas cloud (center dark area) in the constellation Musca resembles a skinny filament. But it’s actually a flat sheet that extends about 20 light-years into space away from Earth, an analysis finds. (Dylan O’Donnell, deography.com/WikiCommons)
When thinking and talking about “astrobiology,” many people are inclined to think of alien creatures that often look rather like us, but with some kind of switcheroo. Life, in this view, means something rather like us that just happens to live on another planet and perhaps uses different techniques to stay alive.
But as defined by NASA, and what “astrobiology” is in real scientific terms, is the search for life beyond Earth and the exploration of how life began here. They may seem like very different subjects but are actually joined at the hip; having a deeper understanding of how life originated on Earth is surely one of the most important set of clues to how to find it elsewhere.
Those con-joined scientific disciplines — the search for extraterrestrial life and the extraordinarily difficult task of analyzing how it started here — together raise another most complex challenge.
Precisely how far back do we look when trying to understand the origins of life? ...