Proof of life: how would we recognise an alien if we saw one?

What would convince you that aliens existed? The question came up recently at a conference on astrobiology, held at Stanford University in California. Several ideas were tossed around – unusual gases in a planet’s atmosphere, strange heat gradients on its surface. But none felt persuasive. Finally, one scientist offered the solution: a photograph. There was […]

The Tallest Tree in the World: Hyperion

Standing at 379.7 feet (115.7 meters) tall, a redwood tree named “Hyperion” is officially the tallest tree in the world. Redwoods (scientific name: Sequoia sempervirens) are the tallest trees in the world, they easily reach heights of 300 feet (91 meters) and even more. They are not the tallest only, also evergreen and very long-lived: […]