Getting to another star: what scientists think is actually possible
Sara Seager and David Kipping both discuss how we might reach other stars, and Ann Druyan tells the story of Voyager and its Golden Record, the craft already on its way out. Together they give a sober picture of the distances involved and of what has been done so far.
How long would it take to reach the nearest star with conventional methods? Show answer
Tens of thousands of years, according to Sara Seager. The star is more than four light years away.
Why is the nearest star an interesting target? Show answer
It appears to have a planet of about Earth's mass in its habitable zone.
What is Breakthrough Starshot? Show answer
A plan to push thousands of tiny chips on light sails with ground lasers to a fraction of light speed for a flyby.
Why does a light sail help? Show answer
It carries no fuel. The energy stays on the ground in the lasers, so the craft can weigh about a gram.
Why send many tiny probes instead of one large ship? Show answer
Mass production accepts that most will fail and counts on a few surviving the journey.
What is Seager's speculation about sending humans? Show answer
It may be easier to send raw biological materials and instructions to print humans than to send people.
What is the solar gravitational lens idea? Show answer
Place a telescope about 500 times the Earth-Sun distance away, where the Sun's gravity focuses light from a distant planet.
Why does David Kipping reject warp drives? Show answer
You cannot have relativity, faster-than-light travel and causality all at once.
What has humanity actually sent toward the stars? Show answer
The two Voyager spacecraft, launched in 1977, which have reached the edge of the Sun's domain.
What is remarkable about Voyager's engineering? Show answer
Built to last about a dozen years, it was still communicating after 42, running on about 11 watts.
What is on the Golden Record? Show answer
About 118 images of life on Earth, 27 pieces of music and a sound essay telling the planet's story.
What does Ann Druyan think is holding us back? Show answer
Nerve more than capability. She says we have the engineering and physics but are a little paralyzed.