Are we Alone in the Universe?

Use the Drake equation to calculate the number of civilisations in our galaxy. For fifty years, the Search for Extra Terrestrial Intelligence has been scanning the galaxy for a message from an alien civilisation. So far to no avail, but a recent breakthrough suggests they may one day succeed. Horizon joins the planet hunters who've discovered a new world called Gliese 581 c. It is the most Earth-like planet yet found around another star and may have habitats capable of supporting life. NASA too hopes to find fifty more Earth-like planets by the end of the decade, all of which dramatically increases the chance that alien life has begun elsewhere in the galaxy.

Other episodes for this season

How to Kill a Human Being
Episode 1 - How to Kill a Human Being
Total Isolation
Episode 2 - Total Isolation
What on Earth is Wrong With Gravity?
Episode 3 - What on Earth is Wrong Wi...
Is Alcohol Worse than Ecstasy?
Episode 4 - Is Alcohol Worse than Ecs...
How to Make Better Decisions
Episode 5 - How to Make Better Decisi...
How to Live to be 101
Episode 6 - How to Live to be 101
Prof. Regan's Supermarket Secrets
Episode 7 - Prof. Regan's Supermarket...
Are we Alone in the Universe?
Episode 8 - Are we Alone in the Universe?
How Much is Your Dead Body Worth?
Episode 9 - How Much is Your Dead Bod...
How Does Your Memory Work?
Episode 10 - How Does Your Memory Work...
The President's Guide to Science
Episode 11 - The President's Guide to...
How Mad Are You? (1 of 2)
Episode 12 - How Mad Are You? (1 of 2)
How Mad Are You? (2 of 2)
Episode 13 - How Mad Are You? (2 of 2)
Jimmy's GM Food Fight
Episode 14 - Jimmy's GM Food Fight
Do You Know What Time It Is?
Episode 15 - Do You Know What Time It...
Allergy Planet
Episode 16 - Allergy Planet
Where's My Robot?
Episode 17 - Where's My Robot?