Conversation

Space rocks

TOPIA meets the stardust expert who
eyeballs fireballs to hunt for water

by

Lisa Goldapple

Stardust expert Ashley King takes TOPIA editor Lisa Goldapple on a cosmic journey via meteorites, Mars, shooting stars, and Elon Musk firing a car into the wrong orbit

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If the last couple of years have made you feel like you’ve come through several supernovas, well, you have. But a long time ago. 

You were made in a star. Around 13.8 billion years ago, the first stars synthesised elements that went on to create gas, minerals and asteroids. Then came the planets, the ingredients required for life, water – and us. Nearly all of the elements in the human body were created in the Big Bang, the supernova blasts that seeded space with heavy elements.

We really are made of stardust.

And we know all this thanks to the teeny, tiny specks from outer space that fall to Earth each day. These relics of the past tell us what materials existed when our solar system was forming, and how the planets were made, as well as the possibility of life and water on other planets. 

As one of the world’s leading – and only – stardust experts, planetary scientist Ashley King is re-invigorating meteorite science. Based below the galleries and dinosaurs of the Natural History Museum in London, he’s the one who’s called when a 4.6-billion-year-old lump falls out of the sky and lands in someone’s garden.

Lisa Goldapple: Hi Ashley. So, you’re a stardust expert. Niche! What does that involve? 

Ashley King: Hi. So, it means I work with rocks that date back to the formation of our solar system – and further. Stardust formed around stars before our solar system existed. It was only in the late-80s that people worked out that you could analyse the tiny presolar materials. To be able to hold a piece of Mars or an asteroid in your hand is amazing. I do it nearly every day but it doesn’t lose its appeal.

And what can we learn from cosmic dust and meteorites?

By studying meteorites, we can learn where there’s water in the solar system and how it’s moving around out there. We know there is water on Mars and the Moon. People always think of the Earth as being really wet and having loads of water, but it’s actually a small fraction of the total mass of the Earth.

How do you know for sure that stardust is that old?

Stardust composition matches with how we think elements are made in stars. In our solar system, chemically everything looks pretty much the same – because everything was mixed together as it was and sort of homogenised. Stardust, not so much – so we know it’s presolar.

So stars are sort of element factories? 

Yes, stars are really amazingly complicated factories that generate all the elements, thanks to nuclear synthetic processes like fusion. When they reach the end of their life, a supernova goes bang, exploding as the elements condense out into dust around the stars. Astronomers can even make models of how a supernova forms. But you can only create a powerful stellar explosion in a model, you can’t build a supernova in a lab.

Have you ever got pissed and tried to make a supernova?!

No, but I’m sure I’ve got pissed and probably eaten a bit of meteorite or something at some point! 

So what’s your favourite meteorite in the museum?

The Winchcombe meteorite. Last year we got to witness a blazing fireball in southwest England thanks to a network of sky-monitoring cameras. We knew quickly that something had landed somewhere near the Cotswolds town. So we went on the news to announce that there might be some meteorites, and a family reported a big pile of black rocks on their driveway. I was dispatched to recover it – and the tarmac too – to help lead all the science. A week later a big meteorite was found on farmland in a field of sheep poo.

But what makes this black splat so important?

It’s the first to be recovered in the UK for 30 years and probably the first material that’s been collected less than 12 hours after landing on the Earth, which makes it the freshest, most pristine meteorite we have anywhere in the world. Most meteorites land and might sit there for days, months, years, billions of years. Also, because we saw the fireball, we also know where in the solar system it came from – the asteroid belt between Mars and Jupiter. 

It looks like a lump of coal, but it’s considered a rare ‘carbonaceous chondrite’. What on Earth does that mean? 

Carbonaceous chondrites contain materials dating back to the birth of our solar system 4.56 billion years ago. It also has water locked-up in minerals and a few percent carbon, some of which forms complex organic molecules. Meteorites like Winchcombe likely played a crucial role in the formation and evolution of water and life on Earth.

Bet you’re jealous of the family in Winchcombe whose garden it landed in. This past year has been weird, do you think anything cosmic is going on?

Ha! Yes! There has been a weird spike in the number of meteorites. There have been several falls that have been very similar to the Winchcombe one over the last few years. It might just be a weird coincidence or it might be a breakup of an asteroid. We don’t really know why that is. It’s a bit odd – but it’s good for us!

What are you analysing right now? Take us into your universe…

I’m part of the Hayabusa 2 team analysing the space samples brought back to us from a diamond-shaped, twirling asteroid called Ryugu. Normally meteorites get contaminated when they come through the atmosphere, even if you collect them within 12 hours. Over the last few years, Japan Aerospace Exploration Agency (JAXA) has been collecting pristine and untouched material that we think has carbon and water. I’ve seen the initial results and it could change how we think about organics and water on Earth. 

How can travelling to the moon help with the Earth’s resources?

People want to go to the moon because we now know there’s ice there. And if there’s ice, you can start making fuel and living there. Further into the solar system, there are whole bodies which are just made of ice. But we can’t just pop along to the moon or to the outer solar system every day. If Elon Musk or somebody wants to build a settlement out on Mars, we can help them understand what the rocks are, how much water there is, how you would extract that water and create housing, or something like that.

But would you help Elon Musk in his mission – honestly?

I am a scientist. We worry an awful lot about a thing called ‘planetary protection’. The big question is always about life on Mars. To get a Rover sent over or a mission flown into space, there are a lot of protocols and hoops to be jumped through to make sure everything’s clean. Because there are no rules or regulations for space exploration, there’s a risk with people like Elon Musk. He fired a Tesla car into space a few years ago, into an orbit that wasn’t exactly what they thought it was going to be – which meant it ended up going much closer to the biggest asteroid in a belt called Ceres. 

What’s Ceres when it’s at home?

Ceres is not talked about so much, but it’s a place that potentially could have had life in the early solar system. It just doesn’t get all the headlines like Mars. I’m always concerned that there’s the risk that people like Musk do stuff like that and a car crashes into Ceres or into Mars, and we’re screwed. We’re never going to answer any of those questions. 

Boys with their toys catapulting cars into space, eh?! But on the plus side, we now have access to space that we didn’t ten years ago. Who are the more grounded people doing groundbreaking work that could really change things for the better?

A big thing for the planetary science world is ExoMars, which is likely to launch next summer. That’s the European Space Agency mission into Mars. It’s been slightly delayed but fingers crossed that will go ahead to address the question of whether life has ever existed there. As well as Hayabusa 2, OSIRIS REx is the NASA equivalent asteroid-study and sample-return mission. In 2023 it’s testing near-Earth asteroid Bennu, which is a potentially hazardous asteroid. It will be a huge international effort to understand these rocks. For me, that’s the really exciting stuff. 

Would you go to Mars? It wouldn’t be much fun living there, would it?

I would go but it would be miserable. You want to go after they’ve been a few times and got it sorted out. It’s the journey as well. You get to Mars in about six months, and there’s horrible radiation and all sorts. 

Just imagine the jet lag. So, do you believe in aliens? 

There are so many stars, and so many planets, it seems likely that some sort of ‘life’ exists elsewhere in the universe. Whether that’s little green men living on a planet around another star, or bacteria swimming around below the frozen crust of a moon in our own solar system remains to be seen…

Is your work dangerous?

I’m a lab-based scientist, so everything’s dangerous in a way. I do a lot of work at the UK’s national synchrotron science research facility, the Diamond Light Source [pictured below]. It’s a bit like a particle accelerator and works like a giant microscope, harnessing the power of electrons to produce bright light that scientists can use to study anything from fossils to viruses. We work in a big round warehouse, accelerating electrons to generate x-rays to do experiments. It’s a high radiation environment and specialised cutting-edge technology. You spend three or four days running your experiments 24/7 with no sleep, and then go and crash when you come back. It’s fun.

Should we believe the doom-mongers who say that planet Earth will be hit by an asteroid – or are they just oddballs?! (That was an asteroid joke.)

Very good! But no need to worry. People watch for that stuff and know what’s coming and how big it is. To prevent the impact of a hazardous asteroid, there’s even a NASA mission launch to fire a missile into an asteroid, on purpose, to work out how strong it is and test technologies. It’s called the DART Mission. We’re not about to have a massive earthquake either, by the way. 

What about death, what happens to the stardust within us when we die?

When you die, you are converted into the next generation of stars. So you seed future stars. At some point, the solar system is going to end and the sun’s going to end too. We know that our sun is about halfway through its life. And in 5 billion years, it will swell up and all the gas will come out and the earth will be gone. 

What do you think about the state of the world today and the direction we’re going, using up all our resources and ****ing everything up?

Ha! I think you put it pretty succinctly. You’re absolutely right. There is a finite amount of stuff available on the earth and big debates to come about how we deal with that. You can look at people like Prince William saying we shouldn’t be launching stuff into space as it’s a massive waste of time and money, but also space is where we develop new technology. Really simple things that people don’t really necessarily connect with space exploration were developed by the astronauts, like the biro.

And the cochlear implant, scratch-resistant lenses and memory foam…  

You wouldn’t have things like mobile phones without space exploration either. Everything runs through satellites. In order to build a satellite and put it there then you need to know what the environment is and how to launch it so space is fundamental. Is going off to Mars and transforming that a sensible thing to do or should we be looking for solutions here? It always comes back down to how stupidly and horribly unequal the world is. You only have to look at the vaccine rollout to see all the rich countries doing okay for themselves and everyone else just left to own devices.

Does space junk create a problem for your work? 

Space junk is becoming a problem for everybody – so many of us rely on satellites for our daily lives. Along with possible collisions with artificial debris, satellites and spacecraft are also bombarded by the same space dust that we study in the lab to learn about the origin of the solar system. For example, we have some solar panels from the Hubble Space telescope that have small impact craters formed by asteroid and comet dust.

Let’s talk about the James Webb Space Telescope. What are you most excited to learn about from this ambitious mission exploring exoplanets around other stars?

I’m really interested in breakthroughs that will be possible in understanding our own solar system. There’s lots we don’t know about asteroids and comets – the ingredients for making planets – and James Webb will help us to study their mineralogy and composition and learn about their geological history.

It’s amazing how it’s the teeny tiny things that have the biggest impact… nanolights, atoms, microbes, bacteria. Size really doesn’t matter does it?

A human hair is 100 microns thick and the bigger presolar grains ones are around one micron. You can’t see these things by eye. You need electron microscopes to study them atom-by-atom, and that tells you about how a star formed. Imagine how massive a star is, yet this tiny thing is smaller than the width of a human hair. That’s the part of the problem with planetary sciences, the scales are completely impossible to think about. And that’s just one star. 

Where can urban micrometeorite hunters look for these mini stardust-filled rocks?

Micrometeorites that reach the ground are often completely remelted, and larger rocks known as meteorites have a dark fusion crust after reaching temperatures of up to 1000C. The Earth is a dusty place (think pollution and aerosols, volcanoes, sandstorms etc), but with some patience it’s possible to search for and identify micrometeorites trapped in ancient sediments, Antarctic ice, or even on roofs and in gutters. 

How can people get involved with what you are doing? The more eyeballs on fireballs the merrier, right?

There’s an idea of scientists as lone wolves, but space missions are amazing demonstrations of what can happen if everybody works together. We are trying to fight the scientist stereotype and encourage more diversity, so it’s not all white middle aged men chatting to each other. One of the best citIzen science projects we are involved in is a camera network that tracks meteors and fireballs. That is how we found Winchcombe. You can put a camera system together for little money and it works like a CCTV camera. If you set it up to record the sky, you will see shooting stars nearly every night – if it’s not cloudy. With lots of different camera angles, us scientists can work out where it’s coming from, so thanks!  

Can you give us any tips or tricks to spot a shooting star? 

Ashley: Shooting stars, or meteors, are the streaks of light that occur when small dust grains from asteroids and comets burn-up in the Earth’s atmosphere. This is happening all the time, but most are too faint to be seen during the day or in big cities where there’s lots of light pollution. The best option is to go out into the countryside on a clear, cloudless evening and “watch the skies”. And be patient, it can take a while for your eyes to adjust to the dark!

Eyes to the skies. So, will we see any exciting asteroid fallouts in 2022? 

We can’t predict them unfortunately. But who knows? Next week you could go out and there could be a new meteorite in your garden. But chances are it won’t happen in the UK again for a while.

Lastly, what’s the best stardust or space geologist joke that you know? 

“Space rocks” just on its own is a decent enough pun!

Amazeballs. Rock on.

— Real rock music: 11 tracks for geology-loving stargazers

Rock Lobster – B52’s
The Amoeba People – Chicxulub
Echo & the Bunnymen – Meteorites
Pozi – Engaged
Phillip Glass – Etoile Polaire (North Star)
Deadmau5 – HR 8938 Cephei
Moby – We are all made of stars
Bowie – Space Oddity Bjork – Mutual Core
The Beatles – Lucy in the Sky with Diamonds
The Beatles – Across the Universe
Budos Band – Volcano Song

What’s so good about this?

Meteorites really do rock. They work as important markers of time that can tell us about the Earth’s history and life on our planet. But chondrites take this to the next level. As some of the oldest meteorites in the solar system, the pristine rocks haven’t been melted or altered much since their formation. It’s thanks to moon rocks that we even learned that it was formed 4.5 billion years ago. So keep your eyes peeled, your eyes to the skies instead of the gutter. And if you see a really bright meteor or hear a sonic boom that isn’t related to aircraft movement click here to report it.  

Meet the writer

Lisa Goldapple is the brain behind the world of TOPIA, and a wise-cracking detective somewhere in the multiverse. She might not behave as good as gold, but thinks Good is golden. Follow @LisaGoldapple and to understand her rare brain – a bit – read Mind Blown. Because, if life splinters and you hallucinate triangles, make a kaleidoscope.