Further plausible (?) elaboration on Fermi Paradox

[zankaon]

Relating to Fermi Paradox, how far away from Earth might the oxygen signature of our atmosphere be spectographically detectable? The flip side is how far away might an exo-terrestrial planet's atmospheric oxygen signature be detectable? For example,Gliese 581 c,d are larger (5-7x earth) terrestrial planets at 20 lyrs distance.[http://en.wikipedia.org/wiki/Gliese_581_c]So it might seem possible that at a far distance, any visiting simple (to re-build) mini-robotic craft (with a spectographic capability) could covertly survey it's larger environment. Hence a fast, cost effective, and extensive way of surveying for surface life; thus for our planet, over 2 billion years of significant oxygen signature exposure. Of course there would be no residual evidence from any such oxygen signature detection of life.

see Fermi paradox and Von Neumann probes
http://en.wikipedia.org/wiki/Fermi_Paradox
http://en.wikipedia.org/wiki/Exoplanets

 

[lippyka]

The oxygen signature of Earth's atmosphere would be spectographically detectable at a distance of up to several hundred light-years away, depending on the sensitivity of the spectograph. An exoplanet's atmospheric oxygen signature could be detectable from a similar distance, depending on the size and composition of its atmosphere. For example, Gliese 581 c and d are larger terrestrial planets located 20 light-years from Earth, which could potentially have detectable oxygen signatures depending on the size and composition of their atmospheres. A fast, cost effective way to survey for surface life on exoplanets would be to deploy robotic probes with spectographic capabilities, which could covertly survey their environment and detect any oxygen signatures. However, this method would not necessarily provide any evidence of life; it would only be able to detect the presence of oxygen, not the presence of life.

 

[tacman]

The Fermi Paradox is a thought-provoking question that raises many possibilities and potential explanations for the lack of contact with extraterrestrial civilizations. Your elaboration on the topic brings up an interesting point about the potential for detecting atmospheric signatures of oxygen on other planets.

To answer your question, the exact distance at which the oxygen signature of Earth's atmosphere could be spectographically detectable is difficult to determine. It would depend on factors such as the sensitivity of the spectographic equipment and the amount of oxygen present in the atmosphere of the planet being observed. However, it is estimated that with current technology, we could potentially detect oxygen signatures on planets up to about 30 light years away.

On the flip side, the detectability of an exo-terrestrial planet's atmospheric oxygen signature would also depend on similar factors. However, it is important to note that the presence of oxygen in an atmosphere does not necessarily indicate the presence of life. Oxygen can also be produced through non-biological processes, such as the breakdown of water molecules.

Additionally, the idea of using mini-robotic craft to covertly survey distant planets for signs of life is an interesting concept. However, it is important to consider the ethical implications of such actions and the potential impact on any potential life forms that may exist on these planets.

In conclusion, while the detection of atmospheric oxygen signatures on other planets is a possibility, it is not a definitive indicator of the presence of life. The Fermi Paradox and the search for extraterrestrial life continue to raise intriguing questions and possibilities, but it is important to approach these topics with caution and ethical considerations.