In late June an interesting object was discovered heading inwards from the outer solar system, identified in archival images from a survey of the sky. It was initially thought to be worth keeping an eye on over the next decade or so, as it approaches the orbit of Saturn before heading back out to the outer reaches - a chance to keep an eye on a distant wanderer. Further observations have shown that 2014 UN271 (its official designation) appears to be active, with a coma and tail like a comet - unusual for an object so far from the Sun. If it is a comet, becoming Comet Bernadinelli-Bernstein, it could be the largest on record, possibly more than 100km across. This month Dr Meg Schwamb, from Queens University Belfast, explains where this objects fits in terms of the size and scale of the Solar System, while Dr Tim Lister, from Las Cumbres Observatory, explains what he and colleagues have found from those early follow-up observations. Find out what to expect over the next decade from this icy visitor, and how future telescopes should help us find out quite how unusual it is.

Pythagorean Astronomy

Herding Megacomets

Our understand of the Universe has changed a great deal in the last 100 years. From Einstein's theories of relativity and measurements of the expanding Universe, to the discovery of the Cosmic Microwave Background and the mysterious Dark Energy. But what are the current mysteries and unknowns that we still want to uncover? And how much is our progress guided by technological developments? Dr Ian Harrison, currently at the University of Oxford, but shortly to return to Cardiff University, studies increasingly precise observations from many different telescopes and observatories, comparing them to theoretical predictions. Dr Samantha Stever, from Okayama University, and formerly an undergraduate here in Cardiff, works on the design and build of scientific instruments designed to make these incredibly precise measurements, including the LiteBIRD satellite currently being built. Between Ian and Samantha, we can journey from our early developments in theoretical understanding the Universe and the initial measurements, to the latest technological achievements that are allowing us to test the current theories to their limits.

Cosmic Developments

This month, we're joined by two people who've just been elected to prestigious roles in science here in the UK. Professor Mike Edmunds has just become President-elect of the Royal Astronomical Society, while Professor Bernard Schutz has recently been elected a Fellow of the Royal Society. Both these societies have a long history, and we discuss their role in the development of science in the UK, and how it has changed. Mike and Bernard have both been here in Cardiff for nearly 50 years, and have seen the way science is done change significantly over that period. But what are their thoughts about the future of astronomy, and of science in general? What are the challenges facing the two societies, and science in general, in the aftermath of the Coronavirus pandemic? What do they think we should we do to protect future of science, and possibly humanity?

Learned Societies and Society Learning

Last September, a team of scientists led by Professor Jane Greaves announced the detection of a rare gas, phosphine, in the atmosphere of Venus. With no plausible explanations of how it could be there, one possibility remaining was that it was being produced by some sort of microbial life floating in the cloud decks of Venus. The idea was seen as preposterous by some, and others even questioned the validity of the detection itself. This month, Jane gives an update on the process of double and triple checking their result, and what the latest is on this exciting process of scientific discovery. It even features 1970s spacecraft! And could there possibly be a spacecraft sent to Venus in just a few years?

Revisting Venus

Where were you on 28th February 2021, just before 10pm? If you were in parts of Wales, or the west of England, you may have seen a bright flash streaking in the sky. This was a fireball - a bright kind of meteorite which is a special sight in its own right. But this was a very special fireball, as the object that created it landed on the ground and has been found, collected and is under analysis right now. To add to the magic, it's also an incredibly special kind of meteorite, and includes some incredibly old material. To learn about the process of finding, collecting and studying these rare finds, as well as what they can tell us about the origins of the Earth, we hear from Dr Martin Suttle and Dr Helena Bates from the Natural History Museum.

Catching a Shooting Star

The idea of life elsewhere is not a new one. Hundreds of years ago it was assumed that there were beings everywhere, before such views were considered heretical, and the determination that places like the Moon were dry airless worlds started to reduce the possible places life could thrive. But even as recently as the mid-20th Century, the idea of vegetation on the surface of Mars was not considered crazy. As the dry, arid nature of Mars became clear, and the hot, hellish surface of Venus was revealed, hope of finding life, or certainly intelligent life, all but disappeared. There was a flurry of interest in the mid-1990s, when a meteorite that originated on Mars seemed to show signs of fossils of tiny lifeforms. Those turned out to be the product of geology. But the search goes on, not just in our Solar System, but also beyond. This month, we are joined by Professor Abel Mendez, who is a physicist and astrobiologist at the University of Puerto Rico, based at Arecibo. We got on to shadow biospheres and technosignatures, but we began by going back to basics, with Abel explaining why we even go searching for life elsewhere.

Astrobiology and Technosignatures

Over the course of the next month, we'll see the arrival at Mars of not one, not two, but three spacecraft: Nasa’s Perseverance Rover, with its little helicopter Ingenuity; the Chinese Space Agency's Tianwen-1 mission, which comprises an orbiting spacecraft, a landing platform and a rover; and the UAE's Hope mission, which is an orbiting spacecraft. In this episode we'll be hearing about the upcoming missions to Mars, as a bit of insight into the Chinese Space Programme. Of course, a sensible question is: why all the interest in Mars? It's a dead planet now – or certainly pretty dead – but perhaps that wasn’t always the way. To find out more I spoke to Dr Peter Fawden, whose expertise is the geological history of Mars. Peter is based at the Open University where he works on the imaging cameras of a future mission: the Rosalind Franklin Rover, due to launch in a couple of years. On Earth we can dig up rocks, or go to a cliff, perhaps by a beach, and look at the layers of rock, studying the order in which they were laid down, and taking samples all the time. But what about on Mars, when we can’t get so up-close and personal with the rocks? Well, it turns out, it's not so very different after all. Peter explains the geological history of Mars, where the Perseverance Rover is going to explore, and what the plans are for Rosalind Franklin rover in a couple of years. We also touch on two very intersting aspects of Mars - water and methane. While it's relatively easy to find people working on Nasa and ESA missions, it's somewhat hard to get information about Chinese missions. Who better to speak to than someone who has their ear to the ground, Freelance journalist Andrew Jones. Andrew writes for a range of publications, where he reports on the Chinese Space Programme. Andrew provides us with some fascinating history of the Chinese Space Programme, and what its other high-profile missions are up to, notably the Chang'e 4 and 5 moon missions. Peter Fawden 03:30 - Martian Geology 13:30 - Perseverance 17:00 - Water on Mars 21:20 - ExoMars Rosalind Franklin Rover 25:25 - Methane on Mars Andrew Jones 29:00 - Chinese Space Agency 38:40 - Chang'e 4 and 5 Moon Missions 45:30 - Tianwen-1 plans 48:20 - Hope

The Martian Triple

With the end of one of the craziest years in living memory, we start with astronomical reflections on the last 12 months - and how far we've come over the course of the last decade. A new results has been published about the structure of our own Milky Way Galaxy, using the emission from carbon monoxide gas. The results, from the SEDIGISM team, show that the galaxy is much more "flocculant", or fluffy, than previously thought. Cardiff-based team member, Dr Ana Duarte Cabral Peretto, explains how the survey of the galaxy was done, and what the results might mean. 00:00 - Reflections of the Year and Decade 08:00 - Galactic Structure

Review of the decade and Galactic dynamics

A show of two halves, this month, starting with watery moons. One isn't so surprising - Jupiter's icy Europa. Known to have an ocean under the thick ice shell, models suggest that the plumes that have been observed may not be from the global reservoir, but from smaller briny pools within the icy crust. The second moon is perhaps more surprising, being our own Moon. New measurements from the airborne observatory SOFIA have shown that there is molecular water within the rocks in some places on the surface, and not restricted to the permanently-shadowed craters. Lunar geologists Marissa Lo and Dr John Pernet-Fisher from the University of Manchester (and the Cosmic Cast podcast) explain why water on the moon is of so much interest. And what are we likely to learn when China's Chang'e 5 mission brings samples back from the Moon later this year. Moving further afield we return to Fast Radio Bursts - phenomena we've covered before a number of times on this podcast. We now have an example of a fast radio burst within our own galaxy, which is repeating its bursts. This gives us a great opportunity to study them in more detail. We finish with some more somber news: the announcement that the beleaguered Arecibo telescope, jewel in the crown of the world's radio astronomy and star of films such as Contact and Goldeneye, is to be decommissioned. Cardiff graduate Dr Rhys Taylor, who previously worked at Arecibo Observatory and regularly uses the telescope, explains quite how impressive the 300metre-diameter telescope is, and what an important role it has played in radio astronomy. 00:00 - Europa 05:05 - Water on the Moon 18:30 - Fast Radio Bursts 21:45 - Arecibo Telescope

Watery Worlds and Tumbling Telescopes

Chris North and Edward Gomez give a round-up of the month in astronomy. Towards the end of October, NASA's Osiris Rex spacecraft grabbed a sample from the asteroid Bennu. What happens next, and what might we learn from these samples? Chris and Edward discuss. There's also an update on Betelgeuse (however you chose to pronousne it), which is not estimated to be closer than previously thought - which means it's smaller? But we're still safe when it goes supernova. Right?! Further afield, telescopes around the world spotted a star getting spaghettified by a supermassive black hole - what an Earth does that mean? An finally, October is the month that Nobel Prizes are awarded. With Sir Richard Penrose, Reinhard Genzel and Andrea Ghez sharing the prize for discoveries related to black holes. (Crucially, recorded before the recent announcement regarding the Moon - but we have something to talk about next month!)

Asteroid Tagging and Stellar Spaghettification

This is a special episode - released a couple of weeks earlier than normal – that’s because we’ve got a very special story to talk about this time. A team of astronomers has detected hints that indicate the possibility that there may be life in the clouds of Venus. Despite the maybes and possibilities, this is an astonishing statement, and we'll explore the discovery in this episode with a few of the people involved in the discovery. This month is also an anniversary of sorts. This podcast has its roots in a monthly item on the Pythagoras Trousers radio show 10 years ago this month. The format has changed over the years, with this extended version of the podcast came later, but when Rhys Phillips and I started, I don’t think we thought we’d still be going 10 years later. The focus right now is definitely on Venus. Although its surface is pretty hellish, at about 50km altitude it's much more pleasant in terms of temperature and pressure, though there's the problem of sulphuric acid clouds. To find out more, we're joined by three people involved with the study - Prof Jane Greaves, from Cardiff University, and who led the study, Prof Sara Seager from MIT, and Dr Dave Clements from Imperial College London.

It's (Almost) Never Aliens

If there’s anything that pricks up the ears in astronomy, it’s black holes. And this month we have not one, but two black hole stories. And, depending on how you count them, four black holes, though two of them no longer exist – if that sounds confusing, then don’t worry, it’ll become clear! Regular listeners will be no stranger to black holes, with them featuring regularly – largely thanks to the work of the LIGO and Virgo gravitational wave experiments, which detect the subtle ripples in the fabric of spacetime as pairs of black holes merge. Those black holes are thought to be the remnants of dead stars, and are typically called “stellar mass” black holes since their masses are typically between a few and a few tens of times the mass of our Sun. The detection we’re talking about this month comes from the third observing run, and is the latest in a string of announcements as the long list of candidate events have been studied in further detail and released. Called GW190521 it was observed in May 2019, and immediately caused a stir among the researchers. To find out why, we're joined by Dr Patricia Schmidt. Patricia was a PhD student here in Cardiff a few years ago, and after working the US and the Netherlands is now back in the UK, where she’s a lecturer at the University of Birmingham. We also come across black holes in the hearts of galaxies, and it’s thought that all large galaxies harbour a so-called supermassive black hole at their core, typically measuring millions or even billions of times the mass of the Sun. A recent study measured the mass of one of these supermassive black holes and found that it, well, isn’t so super. Dr Federico Lelli, from Cardiff University explains all, from what a supermassive black hole is, to why this one is so interesting. An extended edition of an original broadcast on 3rd September 2020 as part of Pythagoras' Trousers on Radio Cardiff.

Black holes - too big and too small

In astronomy, the month of July has been the month of two things: comets, and Mars. Comet Neowise, or to give it it’s full title C/2020 F3 NEOWISE, has graced the skies of the northern hemispheres, becoming the first naked eye comet for some time. Some have even argued it’s the best comet for decades. In terms of new missions, then this summer marks the best window to launch missions to Mars. These windows come around roughly every two years, or so, since that’s how long it takes for the Earth to line up with Mars’ position around its orbit. This launch window, no fewer than three countries are taking advantage of the opportunity: the United States with the Perseverance Rover, China with the Tianwen-1 orbiter and rover and the United Arab Emirates with the Hope mission. But from missions to Mars to mission to the Sun. Back in February this year the European Space Agency launched the Solar Orbiter mission to study our star and try to answer some of the remaining mysteries. With the first set of initial images and results out, Professor Lucie Green, from the Mullard Space Science Laboratory, provides an update. An extended edition of an original broadcast on 30th July 2020 as part of Pythagoras' Trousers on Radio Cardiff.

Solar Orbiter: Not Suitable for Vegetarians

Science news stories normally revolve around something new that's been learned, or some question that’s been answered. But sometimes, and these are often the most interesting times, there’s an observation or discovery that raises a whole new set of questions – and the mystery deepens. This month we discuss two such discoveries. First of all, an unusual gravitation wave event, detected back in August 2019 and dubbed GW190814. We’ve discussed gravitational waves a number of times on Pythagorean Astronomy before – these ripples in space that are caused by, among other things, massive objects spiralling in and merging. Cardiff University researchers Dr Fabio Antonini and graduate student Charlie Hoy explain why this discovery is unusual, and what we know about the source objects. Second up is the conundrum of Fast Radio Bursts. First discovered in 2007, the latest discovery in the unravelling detective story was made by the CHIME telescope, and involves a fast radio burst that appears to repeat on a roughly 16 day timescale. The study was led by Dongzi Li, a graduate student in Toronto University, who explores what might create such a peculiar signal. An extended edition of an original broadcast on 2nd July 2020 as part of Pythagoras' Trousers on Radio Cardiff.

Mass Gaps and Radio Bursts

Amid the turmoil of not only coronavirus, but also anti-racism protests across the US and now internationally, it's been a notable month for spaceflight. At the end of May, SpaceX launched their first crewed Dragon capsule, which became the first private vehicle to dock with the International Space Station. But the private space sector is much bigger than SpaceX, and is a very international field. There are many companies based here in the UK, including Small Spark Space Systems Ltd, based here in Cardiff. Comprising around a dozen people, and led by CEO Joe Ward, SmallSpark is a relative newcomer. Joe is, in fact, one of our own - a Cardiff physics graduate from a couple of years ago. This month, Joe explains what SmallSpark is, and what the future might have in store for commercial launches from the UK. An extended edition of an original broadcast on 4th June 2020 as part of Pythagoras' Trousers on Radio Cardiff.

SmallSpark

Astronomy news and interviews with scientists involved in the discoveries.