Stellar astronomer and TED Senior Fellow Lucianne Walkowicz works on NASA’s Kepler mission, searching for places in the universe that could support life. So it’s worth a listen when she asks us to think carefully about Mars. In this short talk, she suggests that we stop dreaming of Mars as a place that we’ll eventually move to when we’ve messed up Earth, and to start thinking of planetary exploration and preservation of the Earth as two sides of the same goal. As she says, “The more you look for planets like Earth, the more you appreciate our own planet.”



  • tipping point – the point at which a series of small changes or incidents becomes significant enough to cause a larger, more important change
  • poised – be or cause to be balanced or suspended
  • treasure trove – a collection or store of valuable or delightful things
  • habitable – suitable or good enough to live in
  • terrestrial planet – a rocky planet is a planet that is composed primarily of silicate rocks or metals


Think about it

Answer the questions below. Pause at times indicated in brackets.

  • What is Kepler? What does it do? (1:09)
  • What is happening to the planet Earth? (1:42)
  • Which aspects of Mars are studied by scientists? Why? (2:50)
  • Why is she worried about colonization of Mars? (4:10)
  • What is Fermi’s paradox? Why does Lucianne believe we should not use Mars as a backup planet?


Practice makes perfect

Fill in the blank spaces with the missing words.

Even ________ just the past few years, we ________ greatly expanded our knowledge of how Earth fits within the context of our universe. NASA’s Kepler mission has discovered thousands of potential planets around other stars, indicating that Earth is ________ one of billions of planets in our galaxy. Kepler is ________ space telescope that measures the subtle dimming of stars as planets pass ________ front of them, blocking just a little bit of that light from reaching us. Kepler’s data reveals planets’ sizes as ________ as their distance from their parent star. Together, this helps us understand whether these planets are small and rocky, like the terrestrial planets in our own Solar System, and also how _____–_ light they receive from their parent sun. ________ turn, this provides clues ________ to whether these planets that we discover might be habitable or not.


Explore it more