Orbital Path signs off with a site visit to NASA’s mysterious and extraordinary building 29.

Billion-year-old asteroid dust, coming right up!

Astronomers investigate a mystery that is 13 billion years old.

NASA develops a futuristic space laser. Launches it into orbit. And aims it directly back at planet Earth.

Humans! Time to get over your three-dimensional selves. 
Brian Greene — world renowned physicist, bestselling author, NOVA host, and serial Colbert guest — explains why.

Has a Bronx plumber’s son become the Einstein of our time?

Three billion years ago, there were organic molecules on Mars. But was there life?

Adults don’t have all the answers — or all the questions. In our second edition of TELESCOPE, Michelle grapples with an 8th-grader’s question about the fate of the Earth.

Adam Riess was only 41 when he was named a Nobel Prize winner. The Johns Hopkins distinguished professor of astronomy shared in the award for his work on something called “dark energy” -- a discovery that over the past 20 years has profoundly shifted our understanding of the universe. Riess made news again recently when he and colleagues working with the Hubble Space Telescope announced new findings about the rate at which the universe is expanding -- findings which simply cannot be explained by physics as we know it. It’s weird and profound stuff. Our story begins a century ago, with a riddle posed by a curious part of Einstein’s Theory of General Relativity — something called the “Cosmological Constant.” The fate of the universe just may hang in the balance.

Adults don’t have all the answers — or all the questions. So Michelle takes on some astronomical queries from 8th-graders.