Explanation:
How strange could alien life be?
An
indication that the fundamental elements that compose most terrestrial life forms
might differ out in the universe was found in unusual
Mono Lake in
California,
USA.
Bacteria in Mono's lakebed gives
indications
that it not only can tolerate a large abundance of normally toxic
arsenic,
but possibly use arsenic as a replacement for
phosphorous,
an element needed by every other known Earth-based life form.
The result is surprising -- and perhaps controversial -- partly because arsenic-incorporating
organic molecules were thought to be much more fragile than phosphorous-incorporating organic molecules.
Pictured above is 7.5-km wide Mono Lake as seen from nearby Mount Dana.
The inset picture shows GFAJ-1, the unusual bacteria that might be able to
survive on
another world.
Best Astronomy Images:
APOD Editor to speak in Philadelphia on Jan 5 and New York City on Jan 7