Observation tells us that there is life on Earth. A question that has to some extent obsessed humanity for centuries "is there life anywhere else". We have no observations that directly answer that question. Until recently we did not even have observations that proved that there were planets around any other star than our Sun. Recent observations are beginning to answer some of our questions, and as is usual in science, leading to more questions.

The space program has given us unprecedented information about the other planets in our solar system. Before then we only had fuzzy pictures of the surfaces of other planets. We didn't even know if a man could stand on the moon, or sink in a surface that was deep in dust. We have walked on the Moon, and brought back rock samples for detailed laboratory analysis. We have sent a probe to Mars that has done detailed chemical analysis looking for indicators of life. So far, we have found no proof of life on Mars. We will soon send another probe that has more sophisticated capabilities to answer that question. The bottom line for right now is that we have not found indicators of life within our solar system other than on Earth.

With respect to all of space we have found what might be a precursor to life. That precursor is what we call self-replicating molecules. A molecule is two or more atoms that join together, like carbon and oxygen. Self-replicating molecules are molecules that can make duplicates of themselves if the right atoms get close enough. Advanced telescopes and sensors have allowed us to observe these molecules in space.

The next question about planets around other stars has also recently been answered. With our advanced technology we have been able to determine that there are planets around other stars. We have been able to define a "habitable zone" where the planet would not be too hot, nor too cold to sustain life. We have very recently been able to determine that there are planets around other stars in their "habitable zones". We are beginning to be able to determine what elements are in the atmospheres of those planets. The content of the atmosphere is important for the existence of life. Our advances in technology are giving us tremendous capabilities to answer some very exciting questions.

Astrophysicists often have the capability to look at the really big picture. In the May 5 Washington Post, Speaking Science, the headline reads, "Stephen Hawking just moved up humanity's deadline for escaping Earth." In November of last year he gave humanity a deadline of 1,000 years to find a new planet to call home. In a new documentary that will be out this summer by BBC's "Tomorrow's World" , "Hawking claims that Mother Earth would greatly appreciate it if we could gather our belongings and get out – not in 1,000 years, but in the next century or so." His reasoning is, "With climate change, overdue asteroid strikes, epidemics, and population growth, our own planet is increasingly precarious."

Now comes the really big question. Can we get to other habitable planets? Mars may be habitable, if we develop the needed technology. We have the technology to make the trip in a "tolerable" amount of time, maybe. However I doubt we could get people there alive. Space hazards – radiation to mention one - would almost certainly kill any human traveling to Mars. Based on the physics that we currently understand, there is no way to get to other stars. Basic physics, based on Einstein's theory of relativity, tells us that nothing can travel faster than the speed of light. It would take an infinite amount of energy to accelerate something to the speed of light and traveling at the speed of light to even the closest star would take years. Unless a new Einstein comes along and discovers a new physics, we can't get there from here, and they can't get here from there.

I'm hoping for a new physics.