This StarTalk All-Stars show that I was lucky enough to host is all about water in the Solar System, entitled ‘Searching for Space Water‘. If you’re in my home country, the UK, then you probably know where all of the Solar System’s water is; hee hee, it’s all around you most of the time. However, if you’re in California, where I’m living at the moment, then you’ll more likely be questioning where all the water went (seriously, no rain since April??!). Anyway, in this episode I investigate where the Solar System’s water is and I’m joined by the fascinating Lindy Elkins-Tanton, director of the School of Earth and Space Exploration at Arizona State University and probably the most water-enthusiastic person I’ve ever met. In the style of Cosmic Queries we have a bunch of questions to tackle sent in by StarTalk fans from all over the world. Lindy and I had no idea what the questions would be in advance and it was the job of comedian and co-host Chuck Nice to reveal the questions to us live. Luckily Lindy was on hand to help me out with answering some of these questions which took us all the way from our own Earth to moons around other planets. It was a fantastic fun-filled discussion; I hope you’ll enjoy listening to the show as much we enjoyed recording it.

I thought it was about time for a little update about my book ‘Catching Stardust’. I’ve been writing for a good few months now and I’m happy to report that it’s going well, and I’m really enjoying the process too. I now have about eight chapters, with about three left to go. Not that this means the book will be finished very soon because once I have everything written then I’m going to need to go back and check what I’ve got as I can barely remember what I wrote back in January now so I assume I might’ve repeated myself a bit…or maybe even missed something out completely…so, I’ll need to have a careful check. It’d be awful to get to the end and find that I’d completely forgotten to explain what a comet is, for example! But don’t worry, I know I haven’t forgotten anything that obvious.

So what have I covered so far and how did I go about approaching writing this book? Having never undertaken such a big writing task before – even my PhD thesis was only 35,000 words and this book will end up around 90,000 words – I decided to start at the very beginning; discussing the beginning of the Solar System. Although I have to admit that this isn’t actually quite the beginning of the book as it will, instead, form Chapter 2. I plan to provide a more general introductory chapter as Chapter 1 which I’ll write at the very end, once I have a much clearer idea of what I’ve actually ended covering throughout the rest of the book. The beginning of the Solar System is a big topic on its own, and I’ve had to summarise some topics within this, for example, the physics as 1) this isn’t my speciality and other scientists are much better placed to describe this in detail (I’ve been reading Carl Sagan’s books and they are just perfect so I’ll refer you there instead) and 2) the focus of this book is more on the birth of the comets and asteroids so the aim here is to put them into the context of the early Solar System, where these objects came from and how they formed.

Of course, before I started putting ‘pen to paper’ (or rather, ‘fingertips to keys’) I began this process with what I thought was a well thought through plan for the book. This seemed like a good idea to wrangle my ideas into a reasonable format, and it gave me confidence that I had enough content in order to make a whole book when I was worried about meeting the daunting word count. However, I’ve surprised myself how much I’ve changed this plan around as I’ve been writing as I discovered that things didn’t end up fitting in exactly where I thought they would. In some cases it didn’t take as many words to describe what I wanted to get across, but in other cases it took much longer as I’d overlooked how important something was, or just that to do it justice for a non-specialist really took some more careful thought.

One of those examples is the subject of meteorites. I was planning to slot them into a chapter with asteroids, but once I got writing about them I had so many words that I found they needed to have their own standalone chapter. In hindsight, it’s such a big topic that it seems obvious that they needed this now but I think I’d just taken for granted what I know about these cool space rocks and forgot that I would need a fair amount of space to get across this excitement. However, as much as I’ll admit that I like plans, I also enjoyed seeing how my book plan changed once I began writing, adapting to new things I wanted to add in or expand upon, and I’m now much happy with the flow of the book from chapter to chapter. I hope that non-specialists can follow my thinking too and if the book is read from start to finish then it should gradually take the reader through the topics, with each chapter building on knowledge learnt from previous chapters, so that they will understand everything I discuss and, more importantly, be as excited about comets and asteroids as I am. However, I was also keen to make each chapter standalone a little bit, sort of like an essay in itself, in case people want to dip in and out of the book (which I wouldn’t recommend because I’d prefer for the whole thing to be read but I like this being an option too) so I think it might also be possible to do this.

Catching Stardust really does cover a lot of ground (or space, perhaps), including life in the Solar System, space missions and space mining to name a few, alongside the basics of what comets and asteroids are, how they formed, and how we analyse them to find out more about the early Solar System. I’m currently working on the space mining chapter, the first of the ‘futuristic’ chapters, as I’ll describe them, simply because the science hasn’t exactly happened yet, but it’s getting close. This chapter has probably taken me the longest so far, involving a lot more research than the others but I’ve learnt so much about this exciting new area of space exploration, and the more I write about it the less like science fiction it seems. There are entire books out there dedicated to the topic of space mining and, of course, I would refer you to these if you want to have a really detailed look in to the subject, but I think that my chapter will provide a good overview of the various space mining plans, putting into context how we might be able to use comets and asteroids in our future. These space rocks don’t just allow us to see into our past, but they might hold the answers for our future to. I’ll leave you with that thought for now.

 

Part 2 of the StarTalk Live! show I was involved in at New York’s Beacon Theatre on Broadway last September is out now and available here or you can listen directly on the SoundCloud link above. Part 1 is already online here as it came out Friday 3^rd June. In Part 2 you should hear all about the New Horizons mission, Pluto and the Kuiper Belt. However, rather hilariously, Neil and I also had a ‘debate’ on whether Pluto should be classified as a planet or not. I took on the argument that Pluto IS still a planet and Neil the opposite…you’ll have to listen to see who wins…or who persuaded the audience of their argument the best anyway. There’s also a hilarious song about Pluto which you’ll have to listen out for.

Here’s a direct link on SoundCloud to my StarTalk Live! ‘Chasing Comets’ podcast from last week. The 2nd part is out tomorrow so I’ll provide a link to it soon. You can also download the show on iTunes. Hope you enjoy listening 🙂

I’m re-posting this article from The Conversation website written my good friend Dr Jessica Barnes about her own new research that has recently been published in the journal Nature Communications. She’s looked at whether comets or asteroids delivered water to the Moon and this work has some obvious implications for water on Earth too. To save you having to sift through the more complicated journal paper I think this article summarises the research really nicely. Good job Jess!

Asteroids most likely delivered water to the moon – here’s how we cracked it

Jessica Barnes, The Open University

One of the moon’s greatest mysteries has long been whether it has any water. During the Apollo era in 1960s and 70s, scientists were convinced it was dry and dusty – estimating there was less than one part in a billion water. However, over the last decade, analyses of lunar samples have revealed that there is a considerable amount of water inside the moon – up to several hundred parts per million – and that it’s been there since the satellite was very young.

But exactly where this internal water came from has remained an enigma. There have been many suggestions, such as comets or asteroids bringing it there. Another is that some of the water could have been there since the moon formed, from material that originally came from the Earth. Now our new study suggests that most of the water inside the moon must have been delivered by asteroids some 4.5 to 4.3 billion years ago.

The moon formed some 4.5 billion years ago – shortly after Earth. But whereas Earth has been constantly renovated through the effects of plate tectonics, the moon has been relatively quiet. The Earth’s ever-changing face means that we know very little of its earliest history. The moon, however, has acted like a time capsule, helping us better understand its history – and the Earth’s.

Digging for water

To probe how water got to the moon’s interior, we performed calculations using published data for water in lunar samples and bulk estimates of water inside the moon. We also used data available for the water content and composition of meteorites and comets. The model also accounted for different types of water, (such as “heavy water” which is made up of relatively more deuterium than hydrogen). This is very useful because because water in different objects in the solar system has different signatures – most comets, for example, have heavy water.

By calculating different mixtures of water from different sources and comparing the results to what we observe for the moon, we discovered that water-rich carbonaceous asteroids are the most likely candidates for bringing the majority of “volatile elements” (elements and compounds with low boiling points) to the moon – such as water, nitrogen and carbon. We also found that comets most likely delivered a maximum of 20% of such elements to the lunar interior.

Based on the data and models currently available, we think that these impacts happened over a couple of hundred million years after the moon formed, just before its huge magma ocean solidified. The asteroids and comets crashed into this magma ocean and were likely retained (rather than boiled off) due to a thermal lid which formed at the surface of the huge pool of magma.

The results are important because they tell us about the kinds of objects that struck both the moon and the Earth more than four billion years ago. Potentially it could also help us understand the origin of water in the Earth. In fact, water inside the Earth is so similar in composition to the water in the moon that, along with other geochemical evidence, it seems likely that our water also came from asteroids.

Of course, this is not an open and shut case, there is still a lot that we do not know about water and other volatiles in the moon and how they relate to each other. For example, we still need to fully understand the processes that operated inside the moon over geological time and work out what happened to the volatiles when lavas were erupted to the lunar surface. We can gain a huge amount of information from further study of samples returned from the Apollo and Luna missions. There are some 382kg of such samples, but only 2% have been investigated for analyses of volatiles.

But ultimately, we need to explore the entire moon to properly understand it. Our work is timely especially in light of the plans to send robotic and human prospecting missions to previously unexplored regions of the moon. In fact, the Apollo astronauts covered a distance on the lunar surface equivalent to a return journey from Edinburgh to Glasgow, so there is every possibility that rocks from the far side and polar regions of the moon may tell a different story.

In addition to the water trapped in glasses and minerals, there is also water-ice and other volatiles on the surface of the moon. As national space agencies gear up for the next era of lunar missions they are primarily focused on investigating how much water is on the surface, where it is and in what form. This will be crucial to determine whether water can be used as a resource for sustaining a moon base or enabling further exploration of the solar system. My feeling is that our nearest neighbour still has a lot to show and tell, and that the next 10 to 20 years are going to be eye-opening.

Jessica Barnes, PhD student, The Open University

This article was originally published on The Conversation. Read the original article.

Tomorrow (June 3^rd) you can listen to Part 1 of the StarTalk Live! show I was involved in at New York’s Beacon Theatre on Broadway last September. It’s a really fun show, mostly because the other guests on stage were hilarious and made the whole experience such a giggle. On stage with me were the amazing Neil deGrasse Tyson as host, joined by Ilana Glazer, Eugene Mirman and Paul Adsit. The audience were also fantastic, as seems usual for StarTalk Live!

I guess the show could be described as a rather ‘icy’ though because we discuss various cold space objects; the Rosetta mission and comets, then the New Horizons mission, Pluto and the Kuiper Belt. As it was a long live show the podcast has been split into two so this week you’ll hear the first cometary half. Part 2, I believe, should be available on Friday 10^th June which covers Pluto and New Horizons, so watch this space for an update. And enjoy!

The show (StarTalk Live! at the Beacon (Part 1): Chasing Comets) is available June 3rd 7pm (EDT) on the StarTalk Radio website, as well as on iTunes Podcasts, Stitcher, TuneIn, SoundCloud and now, on Google Play Music.

I’m so excited to be able to finally announce my news. I’ve just found out that the popular science book I’m currently writing called ‘Catching Stardust’ has been commissioned by the publisher Bloomsbury Sigma. I’ve been busy the last few months doing a lot of writing, and yet there is still a lot more to be done. So, don’t hold your breath on the book coming out just yet, it’s going to take a while longer…but masterpieces don’t happen overnight do they (hee hee)? The publication date is currently set for early 2018. Oh, and the picture was taken by a very talented friend of mine and will be my official author photo, so exciting!!*

So what’s it all about then?

Catching Stardust is about how we use comets and asteroids to probe all the way back to the beginning of the Solar System. It’s sort of a whistle-stop tour through 4.6 billion years of space history…riding on the back of a speeding comet. Sound like a lot to fit into one book? Well, I wouldn’t want to short change you so I’m trying my best to cover as much as is humanly possible!

My book will have a strong focus on the story of the comets, from their formation in the far outer reaches of our evolving Solar System to their importance for understanding our place on Earth. I’ll look at how the Solar System initially formed, condensing from a big swirling cloud of gas and dust in space, and how the comets and asteroids mopped up all these early Solar System ingredients, including all the organic matter and water that was eventually delivered to Earth to create the biological powerhouse we are today!

To understand all this, Catching Stardust will look at some of the most recent space missions that have pushed the boundaries of science and technology to sample objects flying about in space; so there will be a strong focus on the NASA Stardust and ESA Rosetta missions, and the science that has come from them.

But it’s not all about the past, comet and asteroid science is far from complete without a contemplation of the potential destructive force comets and asteroids could pose to humanity. After all, although in living memory we haven’t experienced a major comet collision with Earth, we believe that a comet impact marked the beginning of the end of the dinosaur heyday. So, Catching Stardust will also look into the future, focusing on how we can use some upcoming asteroid sample return missions to inform us about the structure, composition and behavior of objects flying close to our precious Earth. Then we might be able to learn to predict their future behavior, and potentially knock them on to a different path if they are headed our way. But that’s not it, we’ll also take a look at the seemingly crazy ideas to mine asteroids in space. You heard me right, mining asteroids…in space! It’s not just science fiction.

Catching Stardust will update you on (nearly) all we know about comets and asteroids today and, if you read it, you should be perfectly placed to understand the exciting results that are due out in the next few decades from future space missions.

Bloomsbury Sigma is a relatively new science imprint and they have so far published a whole range of science books on topics as diverse as evolutionary biology, astronomy, robotics, paleontology, bio-engineering, and climatology. The one thing in common apart from the science though is that all the authors are amazing science communicators. I’ve been wanting to work with Bloomsbury for a few years and I’ve been wanting to write a popular science book for even longer, but work commitments meant that I had to put my ideas on hold. My move to the USA has allowed me the freedom to concentrate on my writing so I’m super excited to be getting words down. I just wish I could share these words with everyone sooner.

I’ll be updating my blog about the book, giving a few teasers every now and then, so you can keep up with the developments.

For now though, that’s it, I must get back to my next chapter…

*Article photo updated on 4th April 2016 because I put the wrong author picture in originally.

Wowowowow, what an absolutely amazing and fun-filled few days I’ve had in New York, back here again for the second time in 6 months and because of StarTalk science.

The reason I’m here again? I’ve been invited to be a StarTalk All-Star (read more here) for the launch of a new podcast series of the show. I was so excited to fly over the US to join in the festivities to kick off the launch of this spin-off show and to record some initial podcasts.

The launch party was fantastic, full of famous science faces such as Neil deGrasse Tyson (obviously since StarTalk is basically his show), Bill Nye the Science Guy (one of the other All-Stars) and even a real life astronaut Mike Massimino (another one of the new All-Stars). There was even ‘Ground Control’ beer containing yeast grown in space!! Trust the amazing StarTalk peeps to have that organised for the show.

I spent the following day recording 3 new shows for the podcast series. These focus on some of the cosmochemistry research topics that I’m most interested in so we went from Forming Moons, where I was joined by Sarah Stewart of UC Davis, to Water in the Solar System with the fabulous Lindy Elkins-Tanton, and we also covered the Rosetta mission where we were lucky enough to be joined by Matt Taylor, ESA Rosetta Project Scientist.

My brain was fried at the end of all this but what a fantastic time it was. And it was all made easier and more fun by the help of the brilliant StarTalk team and in particular, Chuck Nice, my hilarious, and well-informed, co-host!

Back home now to continue book writing, it’s going to seem very quiet in the office after all this excitement!

P.S. I should point out that these shows will all be available soon on iTunes, YouTube, ConnectPal and startalkradio.net

Triple oxygen isotopic composition of the high-³He/⁴He mantle

Published Open Access in Geochimica et Cosmochimica Acta, Volume 176, 1 March 2016, Pages 227–238.

I promise to write an explainer on this research soon because I realise the title of the paper is not particularly friendly to non-specialists (to say the least). This project relates to work I was doing during my PhD, looking deep into the Earth’s mantle by analysing samples of ancient volcanoes, but I just couldn’t leave it behind. Because I’m a geochemist I like to try to analyse every element I can, and we hadn’t done oxygen isotopes in these samples so a few years later it’s now done. There is of course a good reason for wanting to analyse oxygen but I’ll explain more when I write my ‘explainer’ blog. There are quite a few authors involved in this work, based across Europe and the USA, so it’s been a tricky project to manage in terms of time zones and opinions, but we got there in the end, particularly after a huge amount of detailed lab work by some of my co-authors (thank you Richard!). It’s so nice to finally see the paper out for the community to read, hopefully they like it!

Another beautiful image has been released by the ALMA (Atacama Large Millimeter/Submillimeter Array) telescope of a protoplanetary disk (see above), but in this one there appears to be evidence for newly-forming planets interacting with their disk. The star system we’re looking at is called Sz 91 and it is 650 light years from Earth. The bright coloured ring that can be seen in the image is a relatively dense and cold dust ring, which is exciting in itself, but the hole in the middle is thought to have been carved out by the formation of some hot gas giant planets. During the formation of the protoplanetary disk, dust and gas migrate inwards towards the central star, and so the forming planets act to stop this movement into the inner parts of the disk. The dust on the outside of the ring still migrates in because of gravitational and aerodynamic forces, hence we get an accumulation of dust in the ring as seen here. The results suggest that the ring is primarily composed of mm-sized particles, and these are expected to eventually form into planets.

It’s really nice for a comet scientist like me to see images such as this because it gives me a glimpse of what our Solar System might have looked like 4.6 billion years ago, a time we can’t otherwise get to (unless someone invents time travel – and even then I’m not sure it’s a particularly welcoming environment we’d want to visit!). The only way we can access this time in our Solar System’s history is to analyse comets because they sample this exact era. But the problem then is that we have to piece together a picture of what it looked like using only chemical analyses, this isn’t easy but we try our best. This is why, despite the fact I’m not an astronomer, I still find these ALMA images fascinating and they can help to shape the theories I put forward in my work that are based on my chemical comet data.

As an aside, my interest in ALMA first stemmed from another of its beautiful images of a protoplanetary disk around the star HL Tau (see above). In this one we see gaps in the dust ring itself which we are told points to the fact that ALMA has caught a picture of this disk at the time when the planets are forming. The young planets are literally clearly their orbit, this is very exciting to see and it is also happening much earlier than we expected, this image is captured when the disk is only 1 million years old. The level of detail in this image is astounding, especially when you consider that this is 450 light years away.