What's the origin of water on Earth?

With more than 70% of its surface covered in water, Earth is rightly known as the "blue planet". But where did this water - so essential to life - originate? While some theories suggest that hydrogen was delivered to Earth from space via asteroids, new research indicates that the building blocks for water may have been present on our planet all along. We chat to Tom Barrett from Oxford's Department of Earth Sciences to find out more.    

What do you do when the subject of your research lies deep beneath the waves? Send down an underwater robot, of course! We chat to volcanologist Sofia Della Sala about her recent fieldwork expedition to Santorini, where she used a Remotely Operated Vehicle, or ROV, to search for hydrothermal vents in the Aegean Sea. These vents - which are like hot springs on the sea floor - could provide vital insight into the volcanic and tectonic activity in the region.

"I still don't believe it happened..." What's it like to face the most famous clock on television? We chat to Oxford mathematician Dr Tom Crawford - best known as the creator of the award-winning 'Tom Rocks Maths' outreach programme - about what it was like to step into Rachel Riley's shoes on Countdown.  What's the best tactic for tackling the numbers round? How did he prepare? Did he really only have 30 seconds to find a solution? Tom gives us a glimpse behind-the-scenes of this British institution. 

One in two people will be affected by dementia in their lifetime - whether that is as a patient, or somebody caring for a loved one. But what happens after a dementia diagnosis? Is there a clear pathway ahead? We chat to Jasmine Blane, a DPhil researcher at the Oxford Brain Health Clinic, about the work she is doing to help support patients in the midst of a dementia diagnosis, and into the future.

In popular culture, Tourette's syndrome is wrongly associated solely with outbursts of swearing in the context of lazy jokes. But in reality, the condition is far more complex than this stereotype suggests. When people without Tourette’s jokingly blame their lack of self-control on the condition, it spreads misinformation and invalidates those who actually live with it. Despite this, comedy - when created by those who experience stigma - can sometimes help challenge stereotypes and shift public perceptions. We chat with Dr Melina Malli from the Oxford Institute of Population Ageing to explore whether laughter can really be the best medicine.

If you were hunting for some fossilised dinosaur footprints, where would you go? To a remote part of North or South America, perhaps? A deserted wilderness for sure... But how about Oxfordshire? We chat to Dr Duncan Murdock from the Oxford University Museum of Natural History about an incredible discovery made right on our doorstep. Photo © Dr Emma Nicholls / Oxford University Museum of Natural History

Shh...hedgehog! It always feels like a privilege to catch a glimpse of one, as it snuffles away under the garden fence. And come the spring, our spiny - and usually solitary - little friends will be feeling in the mood for...romance. But what exactly does a female look for in a mate? And how do their intimate encounters even work when things are so very... spiky? Join us for this special Valentine's Day edition of the Big Questions Podcast, as we ask Dr Sophie Lund Rasmussen (aka Dr Hedgehog) "how horny are hedgehogs?"

Electric eels are pretty amazing creatures. Their bodies can release powerful electric charges - in some cases reaching 650 volts! So, what can scientists learn from these animals? Could nature hold the key to advancing our own energy solutions? We chat to Dr Yujia Zhang about how electric eels might inspire the batteries of the future.

Whether it's the bottle of water that you hastily grab at the train station, or your favourite guilty-pleasure fizzy pop, you may have noticed something different about your drinks lately - or at least their containers. Since July 2024, it's been EU law that bottle caps are attached, or 'tethered', on all single-use plastic bottles. But what exactly is the reason for this change? Will it really help to save the planet, or is it just there to annoy us? We chat to Dr Diogo Veríssimo about "nudge", "sludge", and changing human behaviour for a better world.

Even if you’d never previously given much thought to the Northern Lights, chances are they were brought to your attention in 2024, when our social media feeds were set ablaze with beautiful images captured by awe-struck stargazers. Usually restricted to more northerly latitudes, this colourful natural phenomenon could be observed in the UK as far south as Cornwall. But why were we treated to this spectacle, and why now? Dr Carly Howett from the Department of Physics explains why we’re seeing the Northern Lights more often this year, and gives hope to those yet to catch a glimpse.