Anybody Out There?

After more than eight months in space, Curiosity has landed on Mars. As it continues its self-checks, it has been sending back stunning images of Earth's sister planet, such as this one from Mars' Gale Crater.

Besides its studies of Mars' climate and geology, Curiosity will be searching for evidence that Mars could at one time have been suitable for life.  Curiosity will also be gathering information necessary for a potential manned landing.

As of this moment, Earth is the only place in the universe that we know of where life exists. The odds that there is life somewhere out there are very high. Considering the vastness of space, the odds are also very high that intelligent life exists somewhere besides Earth. 

Still, after decades of searching, we have not found any other life,let alone other intelligent life. Physicist Enrico Fermi reportedly commented “...so where are they?” on the absence of any signs of other intelligent life in spite of the probability that such life exists.

I am not sure what would be the more awe-inspiring scenario – that we are totally alone in the vastness of this universe or that our galaxy is teeming with advanced technological civilizations. If we are indeed alone, then, as the only beings capable of looking into space-time and understanding it, we have an awesome responsibility. On the other hand, if Curiosity can provide definitive evidence that life existed at one time on Mars, then at least part of our burden is lifted. If life arose on two planets just in our solar system, then with billions of other solar systems out there, maybe life is not as rare and as fragile as it has seemed until now.

Besides the search for evidence of life or its possibility, the other special objective of the Curiosity mission is to gather information necessary for a manned mission to Mars – currently planned for 2030. Frankly, I am disappointed that we haven't already had a manned landing on Mars. It's been 43 years since man set foot on the Moon. It has been many years since the last manned Moon mission and since then, we have traveled nowhere else. If we spent less on weapons systems and war and more on space systems and exploration, we might have been there by now and the world would have been better off. A manned mission to Mars would be a truly heroic achievement – all the more so, if this could be done by an international team. It would engage the adventurous and scientific energies of mankind and we would be one step closer to making space exploration a reality.

So, here's wishing the best to our robotic envoy. Good luck, Curiosity.

Related

The Drake equation is the classical formula for calculating the probability of the existence of technological civilizations. It was presented in 1961 by astronomer/astrophysicist Frank Drake.

The equation is usually written:

N = R* • fp • ne • fl • fi • fc • L

Where,

N = The number of civilizations in The Milky Way Galaxy whose electromagnetic emissions are detectable. 

R* =The rate of formation of stars suitable for the development of intelligent life.

fp = The fraction of those stars with planetary systems.

ne = The number of planets, per solar system, with an environment suitable for life.

fl = The fraction of suitable planets on which life actually appears.

fi = The fraction of life bearing planets on which intelligent life emerges.

fc = The fraction of civilizations that develop a technology that releases detectable signs of their existence into space.

L = The length of time such civilizations release detectable signals into space.

The factors that one plugs in are conjectural. Basically, you can get any answer you want to believe.

The authors of the Wikipedia entry on the Drake equation used maximum and minimum values that have been proposed in recent years for the factors in the equation. The answer ranged from a low of 8 x 10^-20 - i.e., not only are we alone in our galaxy, we may be alone in the whole universe – to a high of 182 million detectable civilizations! Hmm, that's no help.

In a 2007article in Cosmos Magazine , Tim Dean estimated a more useful range for N, the number of detectable civilizations in the Milky Way Galaxy.  He calculated N to be between 0.00127 (As Dean writes: “To put that in perspective, it means that over a 100,000-year period, around 127 detectable civilisations will crop up but they may not overlap.") and 245 detectable civilizations in the Milky Way Galaxy. 

Fermi's paradox is based on Fermi's “so where are they?” comment - the apparent contradiction between the high probability that intelligent life exists given the scale of the universe and the absolute lack of any evidence that it does exist elsewhere. The Wikipedia entry is excellent and I'll just summarize its theoretical answers to Fermi's paradox here. The arguments fall into one of two categories – there are few, if any, other technologically advanced civilizations or they do exist but we do not see the evidence.

Few, if any, other civilizations have arisen because...

• No other civilizations have ever arisen
• It is the nature of intelligent life to destroy itself
• It is the nature of intelligent life to destroy others
• Life is periodically destroyed by natural events
• Human beings were created alone.
• There are many, many more young universes than old, Universes with civilizations will almost always have just one, the first to arrive. This argument is based on multi-verse theory.

They do exist but we see no evidence because...

• Communication is impossible due to problems of scale
• Communication is impossible for technical reasons
• They choose not to interact with us
• They are here but unobserved