U3A Talk - Are We Alone in the Universe?

“Are We Alone in the Universe?” Our solar system has planets – Mars, Jupiter, etc. – and dozens of moons. Some of them might possibly harbour some sort of primitive life, such as bacteria. Meanwhile our galaxy, the Milky Way, has more than 200 billion stars, most of which seem to have planets. Astronomers have estimated that there may be more than ten billion planets that could sustain life. The question is, “are there any aliens out there?” Another scintillating talk by Adam Hart-Davis.