I'm Alan Olga and this is clear and vivid conversations about connecting and communicating. I was working on how you would identify planets that could host life.

And that was something that not many people did then because we had none.

We didn't know if they existed.

And so I was making an educated bet that they must exist and so it's preparing us for when we found these first

signals we would have to look for and he basically had these two planets that fit that were at the right distance and small enough to be rocks,

and he wanted me to have a look at them to see whether or not those could be potential

habitats.

That's Lisa Kaltenager. could be potential habitats.

That's Lisa Kaltenager. She's a pioneer in figuring out how we might tell

if any of the trillions of other planets out there in the galaxy

might harbor life. And if so what kind of life, perhaps even a kind of life

we've never imagined.

This is her second visit to Clear and Vivid and we'll be talking about her new book,

Alien Earth's.

This is great. The last time we spoke, we said we couldn't wait to talk again and now here we are two years

later.

It is perfect. Isn't it nice? I get the impression that a lot has

happened in those two years. Yeah you have to bring me up to date. Absolutely.

So basically since we've discovered the first exoplanet in 1995, every other day we know of one more.

And so we up to 5,600 known planets to date and we have 10,000 candidates, a bit more actually that we're still vetting, making sure that the signal is good, that there was no error on the detector.

So we really now up from hundreds of exoplanets when we talked last time

to now having more than 5,600 confirmed planets around the

...