I'm John Batchel with my colleague David Livingston, Doctor Space of the Space Show,

and we're delighted to be able to speak to Harold Connolly, a mission sample scientist for Osiris Rex's return of a sample, a small sample, of Benu, the asteroid Benu, a carbonaceous chondrite.

And the new language I've learned, Harold, to start this conversation,

is that there's evidence of hydrothermal layer inside Benu.

What does that mean?

Right.

So in the early stages of geologic change of rocks known as metamorphism, what happens is fluid begins

to move through as the rock slowly heat up. In this case, in an asteroid, when the ices that were

accreted began to melt. And that fluid moves through, it interacts with the minerals that are

already there, and it changes them to new minerals.

And that fluid continues to change in composition as it moves through and changes different

minerals. And eventually that fluid begins to precipitate out new minerals as well. And that's

the sequence that we're talking about here today. And why is that important to discover that in Banu?

Did we know that before, or is this the first time it's been revealed?

No, great point.

So one of the major issues we have is that the meteorites have fall to Earth are

essentially devoid of these late-stage minerals that form from

fluid moving around an asteroid, known as evaporates, or commonly we call them salt. So what we have

here is a pristine sample, as well as a sample from asteroid Rugu, where in the case of Benuo,

we discovered a whole suite of these salts, which we have the sample

preserved in nitrogen, both at Johnson Space Center in the curation facility, when it gets shipped

to colleagues around the world who are analyzing it and in their laboratories. And those salts

...