LMR-084 · Life
Biosignatures
Chemical fingerprints of life. JWST is sniffing for them right now.
§ A first look
§ Depths
Six ways into the same idea — from bedtime story to chalkboard. No order required.
L1 · Crayon
Told like a bedtime story.
For a curious 10-year-old. No jargon. Just a picture in your head.
When we point a telescope at a planet around another star, we can't see anything alive on it directly. But we can look at the colours of light that come through the planet's air, and those colours tell us which gases are floating around in it. Certain gases wouldn't last long on their own — they'd disappear unless something is constantly making more. On Earth, plants and tiny living things constantly make the oxygen we breathe. If we ever see a strange mix like that in another planet's air, it would be a hint that something alive might be there. That kind of hint is called a biosignature. Possibly the most expensive game of 'spot the smell.'
§ Strange but true
- 01Oxygen in an alien atmosphere would be a smoking gun — it's so reactive, something living has to keep making it.
- 02Methane + oxygen together is a near-impossible chemical pair without life to refresh both.
- 03JWST is already sniffing the air of planets around other stars, looking for the chemistry of breathing.
§ From the field journal
Biosignatures
"Chemical fingerprints of life. JWST is sniffing for them right now."
— observed, sketched, not yet fully understood.
§ Nearby
Constellations near Biosignatures
→
Exoplanet
There are more planets in the galaxy than stars in it.
→
JWST
A telescope tuned to see the first galaxies that ever lit up.
→
Habitable Zone
The 'not too hot, not too cold' orbit. Earth is in it. Probably others are too.
→
Drake Equation
A recipe for guessing how many alien civilizations there might be.