Special: Space

WREN GILLET: Hi Wren here with a BTN special that is out of this world, yep it's a space special! Coming up we find out what happens to our bodies in space and learn all about black holes!

WATER ON MARS

WREN: But first, to Mars. Scientists say that deep under the planet's surface is an ocean's worth of liquid water. Justina finds out what it could mean for the possibility of life on the Red Planet.

JUSTINA: Ever dreamt of a drink that's out of this world, like seriously out of this world. Introducing Mars Water. Straight from the newest discovery on the Red Planet.

ASTRONAUT: Mm, I can taste the iron.

JUSTINA: Mars Water, where the future is refreshing. Available 2060 at your nearest space station.

Yep. According to scientists, Mars water is a real thing. You see scientists from the University of California reckon they've discovered liquid water under the surface of Mars and say there's enough of it to cover the planet with an ocean at least a kilometre deep. Although.

VASHAN WRIGHT, UNIVERSITY OF CALIFORNIA: The liquid water is roughly eleven to twenty kilometres beneath the subsurface and getting that liquid water would be quite challenging.

So, how did they figure all this out? Introducing NASA's Mars InSight Lander. It touched down on the planet in 2018…

ANNOUNCER: Touchdown confirmed.

…and until it shut down a few years ago it's been sitting quietly listening to the pulse of Mars measuring how fast seismic waves from Marsquakes travel through the planet. And because sound travels at different speeds through different materials, they could work out water was deep inside the planet.

DR. CLARE KENYON, ASTROPHYSICIST: This is the first time that we have evidence for liquid water on Mars, which is why this is so exciting.

VASHAN WRIGHT, UNIVERSITY OF CALIFORNIA: Water affects just about everything about our planet's evolution. We know that water is a key ingredient for life as we know it. It means that it's potentially habitable in the mid crust of Mars.

While Mars is hundreds of degrees colder than Earth and hardly has any oxygen. Mars and Earth actually have a lot in common. Mars has got polar ice caps, volcanos and seasons. And some scientists reckon that billions of years ago Mars was a lot like Earth today.

DR. CLARE KENYON, ASTROPHYSICIST: There's actually history that Mars had surface water a long time ago in the past. So, when we look at the rocks, we see evidence of, you know, dried out by ocean basins or lake basins, and we see streams; we see canyons that look like they were carved by water just like on Earth.

In fact, Scientists think it's one of the few places in our solar system, other than Earth, where life may have once existed. And may still exist… errr, probably not like this…

ALIEN: Oh.

…but in some tiny form. Some also think that Mars could one day support human life. And some big companies and organisations are spending a lot of time and money to try to get there, conducting all sorts of experiments to work out how they could make the journey and live on the surface. And while the discovery of liquid water is big news it may not be that helpful.

DR. CLARE KENYON, ASTROPHYSICIST: Drilling 10 kilometres down is really hard, even on Earth, let alone on Mars.

And there are some other things to work out.

DR. CLARE KENYON, ASTROPHYSICIST: So you've got to be able to land, you know, you've got to build a habitat, which we don't really know how to do yet, and then you've got to somehow have a ship to get you back in, you know, about a year. And that's a very long time to do all those things. And you'd want to get it right if you're going all that way.

But while it might be some time before we see humans living on the red, dusty planet, and taking a refreshing sip of cool, Martian water. It's still an exciting step in our understanding of life in our solar system.

Did you know

Did you know, Mars got its name from the ancient Romans. The planets reddish colour reminded them of blood so they named it after their god of war — Mars!

ASTRONAUTS RETURN

WREN: Earlier this year astronauts Butch Wilmore and Suni Williams finally headed back to earth after an eight day mission turned into a nine month stay on the International Space Station. It got us wondering how space affects the human body. Here's Aiden.

AIDEN MCNAMARA, REPORTER: It was a moment nine months in the making.

NASA, VOICE FROM CONTROL ROOM: And splash down. Crew 9 back on Earth.

REPORTER: As Butch Wilmore and Suni Williams finally arrived home.

In case you need catching up, let's rewind. The two NASA astronauts arrived at the International Space Station last June; originally booked for an 8 day stay, but the capsule they were set to ride home in was deemed unsafe, so they were kind of stranded in space.

STEVE STICH, NASA COMMERCIAL CREW PROGRAM MANAGER: I want to make it very clear that Butch and Suni are not stranded in space.

REPORTER: Ah ok, well, they were at least stuck there for a bit. Long enough to see out the Paris Olympics, the US election…

BUTCH WILMORE, NASA ASTRONAUT: I actually voted early, a couple of weeks ago.

…and Christmas.

In fact, they were up there for a total of 286 days, orbiting the earth more than 4,500 times. That's 286 days without breathing fresh air or having a proper shower. But one more thing they had to get used to pretty quickly was how space would affect their bodies.

STEVAN GILMORE, NASA LEAD FLIGHT DOCTOR: There's an adaptation phase that happens right away when you get up to space.

REPORTER: This is Doctor Stevan Gilmore, the lead flight surgeon for the mission.

He says when people go to space the human body has to adjust to being in microgravity.

That means there's hardly any gravity pulling them down — which makes them float around in a constant state of weightlessness. While it might look pretty fun, there are some not-so-fun side effects. The first thing that hits is…

STEVAN GILMORE: Basically a kind of motion sickness in some people to adapt to this new environment that doesn't have gravity in it.

REPORTER: You see on Earth you always know which way is up or down.

But in space, there's no clear sense of direction and the human brain gets pretty confused leaving astronauts feeling dizzy or sick. But after a few days they start to adjust to their new environment and start to feel a lot better. Then there's the bone and muscle loss. Without that downward pull we're used to our muscles get weaker because they don't have to work as hard and our weight-bearing bones like our spines and hips lose density because they don't have to support our bodies as much.

STEVAN GILMORE: Those all start decreasing if you don't do anything to counteract it.

REPORTER: That's why there's a high-tech gym on the International Space Station, where astronauts work out at least two hours a day, six days a week to keep their bones and muscles healthy and strong.

STEVAN GILMORE: We kind of view exercise as a great big pill that we have the crew take.

REPORTER: There are heaps of other weird and wacky things that our bodies have to deal with in microgravity.

Like facial puffiness, having a weakened immune system, even vision changes. But there is one pretty cool thing that happens all to do with our height. Believe it or not, space actually makes you taller. Without gravity pushing your spine down, every vertabrae has a chance to move up. So astronauts can actually grow a few centimetres while they're up there, but they do shrink back to normal when they come home.

Speaking of coming home, that's another big adjustment. You might've noticed Butch and Suni were helped out of their spacecraft and wheeled away on stretchers. That's because their bodies have to get used to gravity again and it'll take some time for them to regain their balance and strength.

STEVAN GILMORE: They kind of have to do the same thing but in reverse.

REPORTER: In fact, they're in for weeks of planned medical tests, studies, and reconditioning and should be back to their normal Earth selves within the next few months.

Quiz

How many Aussies have gone to space? 2, 4, or 6?

It's 2, Kinda. Paul Scully-Power and Andy Thomas have both been to space, But in order to do so they had to become US citizens.

BLACK HOLE DISCOVERY

WREN: Finally, an Australian team of astronomers have discovered the fastest-growing black hole that's ever been observed by humans. Thomas found out more about the discovery and what black holes are.

THOMAS MIDENA, REPORTER: Oh, hi, I'm just trying to wrap my head around this.

Black holes. Weird things in space that suck things in.

DOCTOR WHO: That's a black hole. But that's impossible.

It's no wonder they've inspired so much science fiction.

TREASURE PLANET: a black hole.

So, what is a black hole?

CHRISTIAN WOLF, AUSTRALIAN NATIONAL UNIVERSITY: Black holes are really just a lump of mass, like the sun, like the Earth, like my body or a rock in the garden. But what makes them black is that the gravity is so strong that not even light can escape.

Black holes usually form when a massive star reaches the end of its life. Having burned all of its energy, it implodes, collapsing in on itself to an infinitely small point known as a singularity, which sucks in everything around it, including light.

CHRISTIAN: Everything that's inside of it, we cannot see. And the border of the black hole we call the event horizon. That's the place once you go beyond not even light can leave.

Outside of the event horizon is something called the accretion disc.

CHRISTIAN: An accretion disk is a giant storm around a black hole. It's all the material that gets laid out for the meal that black hole is going to have over the next weeks and months.

From a distance, glowing accretion discs can look just like stars. But, in 2019 we got our first up close look at an actual black hole. Followed by this photo which was taken in 2022.

CHRISTIAN: That's Sagittarius A star, the black hole at the centre of our Milky Way.

It's about 26 million kilometres in diameter. So, if this was the Earth, then in comparison, the Sagittarius black hole would be about the size of this entire oval. But if you think that's big, check out the latest black hole that's been discovered by researchers at the ANU. The J0529-435.

CHRISTIAN: Internally, we just call it J0529. So finding these fast growing black holes is like finding a needle in the haystack, because they're really rare. You look at the sky, you see lots of stars. Maybe one of them is a fast growing black hole, but you don't know unless you study them in detail.

It was Christian's job to choose which stars study. And it turns out he chose well, because this black hole they've discovered is a whopper, it's accretion disc is seven light years in diameter. It's bright enough that it's possible to see it from Earth with a backyard telescope. When the stars are out. At night. With a telescope a bit bigger than that one.

Oh.

CHRISTIAN: But this object is so far away, the light has been traveling for 12 billion years.

12 billion years?

CHRISTIAN: 12 billion? Not million. Indeed.

Scientists like Christian are pretty excited about what black holes like this one could teach us about the universe.

CHRISTIAN: So, black holes are really mysterious things. We don't know why they are as massive as they are. How have they been born? We don't even know whether these black holes formed among the stars, or whether they were made through a mysterious way in the Big Bang itself. We also don't know what happens to material after it falls into the black hole.

Sounds like there's plenty more to learn about these mysterious wonders.

Closer

WREN: Well that's all we have for this BTN Space Special. You can check out more specials like this on the BTN website, along with plenty of other things to see and do. Thanks for watching and I'll see you next time!