“The Pale Orange Dot” –NASA Looks at Early Earth as an Alien Planet
For astronomers trying to understand which distant planets might have habitable conditions, the role of atmospheric haze has been hazy. When haze built up in the atmosphere of Archean Earth, the young planet might have looked like this artist’s interpretation – a pale orange dot.
In the best case, haze in a planet’s atmosphere could serve up a smorgasbord of carbon-rich, or organic, molecules that could be transformed by chemical reactions into precursor molecules for life. Haze also might screen out much of the harmful UV radiation that can break down DNA.