Astronomers Find Exoplanet That May Be Covered In Water

12:11 minutes

This illustration shows what exoplanet K2-18 b could look like based on science data. K2-18 b, an exoplanet 8.6 times as massive as Earth, orbits the cool dwarf star K2-18 in the habitable zone and lies 120 light years from Earth. Credit: NASA, ESA, CSA, Joseph Olmsted (STScI)

Scientists using the James Webb Space Telescope made an exciting discovery this week: Exoplanet K2-18 b, 120 light years away from our solar system, could be covered by a water ocean, similar to Earth. Astronomers say this could be a big leap in our exploration of life on other planets.

This news comes amid another JWST discovery: The earliest black holes seem to be much larger than black holes today. This news also provides evidence that black holes can form without stars, a theorized phenomenon that has never been directly observed.

Joining Ira to talk about these and other science stories of the week is Tim Revell, Deputy U.S. Editor of New Scientist, based in New York, New York.

Segment Guests

Tim Revell

Tim Revell is Executive Editor at New Scientist in London, England.

Segment Transcript

IRA FLATOW: This is Science Friday. I’m Ira Flatow. Later in the hour, what we can learn from radioactive wildlife and the struggle of keeping cool while waiting for public transit.

But first, scientists using the James Webb Space Telescope have made an exciting discovery– exoplanet K2-18b, 120 light years away from our solar system, could be covered by a water ocean, and it shows evidence of possible life. Scientists say this could be a big leap in our exploration of life outside of our planet.

And joining me to talk about this story and other science news of the week is my guest Tim Revell, Deputy US Editor for New Scientist, and host of the New Scientist weekly podcast. He’s based in New York. Welcome back, Tim.

TIMOTHY REVELL: Hello. Thanks for having me.

IRA FLATOW: You’re welcome. This sounds pretty exciting. What makes it so special?

TIMOTHY REVELL: Yeah, there’s been a lot of excitement about this one this week. And a lot of that has come from a tentative sign of this molecule called dimethyl sulfide, or DMS, that’s been spotted in the planet’s atmosphere. And the thing about DMS is that it’s only produced by life, on Earth anyway, and that’s mostly by phytoplankton. So that could mean that it’s a sign of life on K2-18b, too.

But it’s worth saying that it’s still just a tentative sign. So we need to do a bit more analysis to really confirm that it is actually present there. And then, of course, it’s also possible that though we currently only know a way for life to produce this molecule, it’s possible that there’s a chemical process that we don’t know of that could also produce it.

IRA FLATOW: What else would they look for to see if there are signs of life?

TIMOTHY REVELL: So typically they look for molecules that can only be produced by life in various different forms. That would be like a real cast iron evidence that there is life on an exoplanet. But they also look for things that we know on Earth is what makes Earth pretty habitable.

So there’s this zone around a star called a habitable region or a habitable zone. And that’s where a planet is far enough away from its star that it’s not too hot, but they’re also close enough that it’s not too cold. And the idea being that you want to have the temperature conditions just right so that liquid water could exist on the planet. And that’s what they found with K2-18b, that it’s actually in this habitable zone.

And then they’ve also found some extra indicators that there could be liquid oceans there, and that’s the presence of methane and carbon dioxide in its atmosphere. And those, astronomers say, really are good indicators that it would have water oceans.

IRA FLATOW: Aha. That’s terrific. The JWST has been pretty busy. It has found supermassive black holes from a long time ago. Tell us why that’s important.

TIMOTHY REVELL: Yeah, these are very interesting. So one of the things that we’re really hoping JWST would be able to do is spot some of the universe’s earliest Black holes, which we couldn’t see with any of the other telescopes that are currently in existence. And it’s been able to do that.

It spotted 20 extremely old supermassive black holes. And it found out that they appeared to be misbehaving based on what we imagine black holes should be doing across the universe. Because very similar black holes that are a little bit younger compared to newer black holes, these older black holes seem to be the wrong size. So they’re between 10 to 100 times too big relative to the other objects in their nearby galaxy.

And so one way of viewing it is that the black holes, well, they’re a little bit too big. But another way of viewing it is that the galaxies that they inhabit are a bit too small. But either way, astronomers are saying something strange is going on.

IRA FLATOW: So what are the implications of early black holes being so huge?

TIMOTHY REVELL: Yeah, so one, we don’t know why they would be this big yet. But one possibility is that what we’re actually observing is a completely different type of black hole than we’ve ever seen before. And that’s called a direct collapse black hole.

Normally, every black hole that we’ve observed before, well, they form from collapsed stars. When stars get to the end of their life, they become black holes– some of them do. But what could have happened in the very early universe is there was enough hydrogen and helium gas flowing about that it could come together and go straight into forming a black hole.

And so there needs to be a little bit further analysis to work out whether that’s what JWST is seeing. But so far, this is the strongest evidence, yet, of us seeing such a black hole.

IRA FLATOW: Let’s move back here to Earth for the historic dangerous flooding in Libya. Just how intense has this flooding been?

TIMOTHY REVELL: Yeah, it’s been really catastrophic. So thousands of people have died in the Eastern Libyan city of Derna. And it could be up to 20,000 people. We just don’t know the numbers yet. And the water, it’s come from a storm called Storm Daniel that’s been hitting the Mediterranean region, and recently Libya, in particular.

And what happened was the storm moved over the very warm Mediterranean waters at this time of year, and that made the storm intensify. And then by the time it got to Libya, it had a huge amount of water that it dumped over near Derna. And then the rain, well, it filled a normally very dry riverbed at this time of year. And that just caused a huge amount of pressure to build up at two dams that are built to protect the city from floods.

Those both then collapsed. They couldn’t withhold that water. And that unleashed a huge torrent across the city, sweeping away entire neighborhoods. One estimate at the moment is that it could be as much as a quarter of the city has been destroyed. And much of the city is now covered in mud.

IRA FLATOW: Do we know if this is a climate change-related event?

TIMOTHY REVELL: So they’ve yet to do the study that definitively says this one was made much more likely because of climate change. But these sorts of storms, they are– we know it’s a pattern that they are becoming more intense. And they tend to linger around areas a little bit longer because of climate change. So that pattern where the storm moved over hot water and intensified, that’s what we’re seeing increasingly happen across the planet. And that is because of warmer temperatures across the planet.

IRA FLATOW: Was it a case that the infrastructure was just not prepared for this level of flooding?

TIMOTHY REVELL: Yeah. So the World Meteorological Organization, their head said earlier this week that had the country had better warning systems in place, that there was enough time for many people to have fled. That wouldn’t have necessarily protected the city. Of course, if the dams had been stronger, that could have done. But Libya has had a decade of serious conflict, so much of its infrastructure has just been greatly reduced in effectiveness.

IRA FLATOW: We hear about earthquakes, flooding, and it’s always the early warning system that’s not working too well. We’ve got more climate news. And this one is a study that says Earth is not doing so well when it comes to supporting humanity. This doesn’t seem so good. What are the details here, Tim?

TIMOTHY REVELL: Yeah, so this is all about a thing called planetary boundaries. And these were broad measures that are meant to look at Earth’s health as a whole that were developed a few years ago by some researchers at the Potsdam Institute for Climate Impact Research in Germany. And there are nine of these measures. And a new study– well, it says that on six of them, Earth is operating beyond the safe operating space for humanity.

IRA FLATOW: Hmm. That’s not good. How are we doing on the other three metrics?

TIMOTHY REVELL: Yeah, so the other three– well, two of them, it says that we’re actually going in the wrong direction as well. And then there’s only one where it seems to be OK. And the things that these planetary boundaries cover– well, the one in the main six group, they represent Earth’s climate, biodiversity, land, fresh water, nutrient pollution, that sort of thing.

And then the ones in the other three, that’s the acidity of the oceans and the health of the air. And those we’re not currently outside the safe operating space, but it’s getting worse. And then the final one is the ozone layer, which is actually doing OK.

IRA FLATOW: Any chance turning things around here?

TIMOTHY REVELL: Yeah, so something that these researchers have been looking at is what the interplay is between the different planetary boundaries. And they found, in repeated simulations, that they’re interconnected. So if one of them worsens, then many of the others do, too. But also, if one of them improves, that can also have effects on the others as well.

And so, for example, they suggest that if we really focused on improving how we treat Earth’s land, for example, by planting many, many trees, that could have a big impact on the biodiversity, planetary boundary, the climate change planetary boundary. It would also improve fresh water. That have many, many different effects.

IRA FLATOW: All right, given all the gloom and doom today, we could use some fun news. And you’ve got a story about how cockatoos make their own drumsticks for mating displays. Are we talking musical birds here?

TIMOTHY REVELL: Yeah, these creatures are absolutely amazing. So the specific cockatoos we’re talking about are called palm cockatoos. And they’re basically like the Ringo Starr of nature.


So they’ve got these rock star spiky crests. They have a very cool red patch on their cheeks. And the males, like you say, they make drumsticks from twigs or seedpods. And then they bash them against trees as part of their mating display to the females. And part of it that I really love is once they’re done, they throw away their drumsticks, which is really like end of a rock concert type of move.

IRA FLATOW: Yeah, yeah. [LAUGHS] They don’t smash them on the tree, though.

TIMOTHY REVELL: Yeah, they don’t smash them on the tree. Although, I imagine sometimes they do break.


But what’s been discovered now is that– we’ve known this for a while that they have these mating displays. But what’s been discovered now is that each drummer has a specific drumstick preference.


TIMOTHY REVELL: Yeah. So when they throw away their drumsticks, obviously this is a perfect opportunity for researchers to go around and collect them. And so they gathered up over 250 drumsticks, and then they found that each individual cockatoo, they seem to have really specific preferences. So some of the ones, they prefer a long, pointy drumstick, and they then stick with that basically the whole of their lives. And other ones, they prefer short stumpy ones. Some of them prefer the seedpods over the twigs. But either way, it’s an individual preference that they stick with.

IRA FLATOW: Our last story is about a really cool superglue alternative made from biodegradable materials. Tell me about that one. I’m waiting for that.

TIMOTHY REVELL: Yeah, so it’s made from soybean oil. And it’s meant to hold as well as most standard epoxies. And so those are glues that are used in many, many different applications, but they’re made out of plastic. And so they take thousands of years to biodegrade.

And this new glue, well, it was inspired by the way that mussels can hold onto rocks. And the glue that they create themselves for that is– it’s organic material. It’s a biosubstance. The team that built this glue from soybean oil, they calculate that if we started using that instead, that the related emissions from glue would go down by about five-fold.

IRA FLATOW: Wow, wow. How much stress can this superglue take?

TIMOTHY REVELL: Yeah, so one of the interesting things about it is depending on exactly how they make it, they can vary how strong it is and how long it lasts. So that means they think that this glue could be used for everything from sticking labels onto cardboard boxes. But maybe for those you’d only want a glue that lasts a week or two before it breaks down and wouldn’t have to be that strong for paper on cardboard. But that they could also make ones that would last years that could be used for things like electronics or even in car manufacturing.

IRA FLATOW: I’m waiting. When could I get this in my market?

TIMOTHY REVELL: Yeah, so that’s always the we might have to wait a little bit moment. They’ve not made this yet at a commercial scale. And that will be the tricky bit. But they think they could be able to do that. And they’ve worked out roughly how much it would cost to do that, which is often a– pun not entirely intended– sticking point in these–

IRA FLATOW: Good one.

TIMOTHY REVELL: –this bits of research. [LAUGHS] And they reckon it would be maybe about 30% more expensive than standard epoxy. So that would be a bit of an increase. But potentially, if it had big environmental benefits, you could get companies willing to switch for that sort of price difference.

IRA FLATOW: Right. Well, Tim, as always, thank you for bringing us such good stuff.

TIMOTHY REVELL: Thanks for having me.

IRA FLATOW: Tim Revell, Deputy US Editor for New Scientist and host of the New Scientist weekly podcast based in New York.

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