The Smithsonian is sharing images of astronaut graffiti aboard the Apollo 11 command module, including this tribute to the spacecraft. Smithsonian Air and Space Museum hide caption

toggle caption Smithsonian Air and Space Museum

"We are very different from all previous species, and we have the power to endure. We also have the power to destroy ourselves." — Lord Martin Rees Ryan Lash/TED hide caption

toggle caption Ryan Lash/TED

TED Radio Hour

Lord Martin Rees: How Can We Ensure Our Survival As A Species?

Astronomer and cosmologist Lord Martin Rees asks whether our species will endure despite the many existential threats we face.

Listen Loading… 7:45
  • Playlist
  • Download
  • Embed
    <iframe src="http://www.npr.org/player/embed/466049421/466437188" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">

A simulation shows gravitational waves coming from two black holes as they spiral in together. S. Ossokine , A. Buonanno (MPI for Gravitational Physics)/W. Benger (Airborne Hydro Mapping GmbH) hide caption

toggle caption S. Ossokine , A. Buonanno (MPI for Gravitational Physics)/W. Benger (Airborne Hydro Mapping GmbH)

NASA Administrator Charles Bolden speaks at a panel discussion on the search for life beyond Earth at NASA headquarters in 2014. Joel Kowsky/NASA hide caption

toggle caption Joel Kowsky/NASA

Luxembourg City, the capital of Luxembourg — shown here in 2012 — mixes the medieval and the modern. The tiny European nation is making a serious bid for the futuristic, too. Loop Images/UIG via Getty Images hide caption

toggle caption Loop Images/UIG via Getty Images

(Left) Bob Ebeling in his home in Brigham City, Utah. (Right) The Challenger lifts off on Jan. 28, 1986, from a launchpad at Kennedy Space Center, 73 seconds before an explosion killed its crew of seven. (Left) Howard Berkes/NPR; (Right) Bob Pearson/AFP/Getty Images hide caption

toggle caption (Left) Howard Berkes/NPR; (Right) Bob Pearson/AFP/Getty Images

A view from Earth of a slender crescent moon in close proximity to the two brightest planets in the sky, Venus and Jupiter. Justin Lane/epa/Corbis hide caption

toggle caption Justin Lane/epa/Corbis

A NASA team has attached nearly all of the hexagonal segments that will together make the primary mirror for the James Webb Space Telescope (pictured are practice segments). Chris Gunn/NASA hide caption

toggle caption Chris Gunn/NASA

The imagined view from Planet Nine back toward the sun. Astronomers think the huge, distant planet is likely gaseous, similar to Uranus and Neptune. Caltech/R. Hurt (IPAC) hide caption

toggle caption Caltech/R. Hurt (IPAC)

An artist's impression of the superluminous supernova as it would appear from a planet in the same galaxy, about 10,000 light-years away. The exploding star is 570 billion times brighter than our sun. Jin Ma/Beijing Planetarium/Science hide caption

toggle caption Jin Ma/Beijing Planetarium/Science