Wednesday, September 30, 2015 7:00pm
Dark streaks on crater slopes on Mars have been identified as salt deposits. The presence of salt could be the strongest evidence of liquid water on the surface of the Red Planet. While Martian surface temperatures range between zero and -100C, the high salt content of the water could act as an anti-freeze, keeping the water liquid.
The movie based on the science fiction book of the same name by Andy Weir details the plight of astronaut Mark Watney, who during a manned mission to Mars, is presumed dead after a fierce storm. He is left behind by his crew. But Watney has survived and finds himself stranded and alone on the hostile planet. With only meager supplies, he must draw upon his ingenuity, wit and spirit to subsist and find a way to signal to Earth that he is alive.
Comet 67P Made from Two Objects
The two lobes that give comet Churyumov–Gerasimenko (67P) its characteristic ‘rubber duck’ shape were once distinct objects that merged after formation. Using high-resolution data from the OSIRIS imaging system on the Rosetta spacecraft, scientists have shown differences between the cometary lobes, made up of stratified, ‘onion-like’ layers. It is thought that the cometesimals were formed by similar accretion processes before they merged, in the early Solar System.
Oceanographers in the ‘ArcticMix’ team have gathered fresh evidence that wind-driven turbulence in the Arctic Ocean is stirring up heat from the depths. The more ice that melts, the more exposed the ocean is to the wind.
Seedbank in Syria
We are never more reminded that we live in a truly global village than when we look at a plate of food. There could be potatoes and tomatoes that evolved in South America, bread made with wheat which started in the Middle East, cassava, now an African staple, originated in Brazil. Crop diversity is of increasing importance and if we want to have this variety of food in the future, with a growing population and a changing climate, we need to look after the hundreds and thousands of genetic varieties of the food plants we grow and eat. And this is where seedbanks come in. Seedbanks are one of the planet’s insurance policies to ensure we can access crop varieties to help improve our crops. But seedbanks are not static ‘museums’ of crop seeds and plant material. Plant breeders, farmers and scientists can, and do, request access to seeds in national collections all the time. But this is the first time an international collection has requested a seed withdrawal from the ultimate seed back up bank – the Svalbard Global Seed Vault. Due to the civil war in the region, ICARDA - International Center for Agricultural Research in Dry Areas that was housed in Aleppo in Syria is moving and it needs its seed deposit back.
(Photo: Dark, narrow streaks on Martian slopes such as these at Hale Crater are inferred to be formed by seasonal flow of water on contemporary Mars © NASA/JPL-Caltech/University of Arizona)
Wednesday, September 23, 2015 7:00pm
As climate change warms our planet some areas of the West Antarctic ice sheet are melting, causing rising sea levels and reducing the amount of heat reflected by the bright white ice sheets. In an unexpected twist a new study has found that as the ice retreats, tiny organisms on the ocean floor are thriving, and their increased growth could play a significant role in capturing and locking away carbon. Given the vast number of these miniature marine creatures their flourishing activity could play a major role in counteracting climate change.
Bumblebee Tongue Evolution
Bumblebees across the globe are having to adjust swiftly to changing climates and shifting plant distributions. As summers warm in alpine regions some flowers are moving uphill in response to rising temperatures. Insects often follow their migrating food source, but in the Rocky Mountains two species of bumblebee have shown remarkable adaptability by rapidly evolving shorter tongues to suit the changing range of local flowers.
Hummingbirds, like bees feed on nectar from flowers and like bees they use long tongues to slurp up the sweet juices. Their tongues are skinny and translucent, with no muscles, but grooves down each side and forked and fringed at the end. It used to be thought that the hummingbird tongues worked by capillary action, with the nectar flowing up the open side grooves. But new very high speed video footage has shown that the tongues are more like a micro-pump. The hummingbird, first squeezes it’s tongue with its beak, so that when it touches the nectar, it springs open, sucking up the delicious liquid more like a syringe or a pump - and this happens at a whopping 23 slurps a second!
Visions of the universe exert an eerie silence. But as Aleem Maqbool reveals in A New Ear on the Universe, on the BBC World Service, all this is set to change. Physicists are racing to develop a cosmic hearing aid which will bring us the Universe’s equivalent of sound - gravitational waves.
Bluetongue virus, which infects a range of animals including cattle, sheep and deer, has recently been reported in Central France and experts are wondering whether or not this might mark the start of a wider outbreak.
(Photo: Giant tabular icebergs surrounded by ice floe drift. Credit: Torsten Blackwood/AFP/Getty Images)
Wednesday, September 16, 2015 7:00pm
Yet more pictures of Pluto are being downloaded and analysed from Nasa’s New Horizons mission to the outer reaches of the Solar system. The latest batch show strange ‘dune like’ features which could indicate wind erosion.
What Birds See in Their Mates
We know that genetic compatibility plays a role when looking for a mate. But is there anything else that animals look for when they choose their partner? Scientists set out to find out in a study of small birds. Zebra finches, are similar to humans in that they mate for life and both parents look after the offspring. So when scientists swapped the chosen mate of one finch with the chosen mate of another, they wanted to see how well these ‘assigned’ pairs got on compared to pairs of birds that had partnered up naturally. The results were surprising.
Do Elite Athletes Use Special Visual Processing to Catch the Ball?
Elite sportsmen and women, like cricketers and tennis players often have less than half a second to respond and catch or hit a ball travelling, at speed, towards them. And, if you think about what processing needs to be done by the brain and the manipulation of the hand, arm, in fact whole body, to position itself in the exact position to grab that ball out of the air – it is a pretty remarkable feat. Professor of Visual Development at Bradford University, Brendan Barrett, has developed some special spectacles to test whether it is something in the visual processing part of the eyes and brain, that makes some people are better at catching a ball than others.
The History of the Future
Melissa Hogenboom goes behind the scenes at the Science Museum in London to explore how our understanding of ourselves and the world around us has changed over time, and often in unexpected ways. She starts with the brain, and how we have studied the mind over the years, from phrenology to EEG and FMRI.
(Photo: A 220-mile (350km) wide view of Pluto from Nasa’s New Horizons spacecraft, shows the diversity of surface reflectivities and geological landforms. Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute)
Wednesday, September 9, 2015 7:00pm
A very deep, hard to access, cave in the Rising Star cave system in South Africa has yielded a massive and important haul of fossilised early human bones. The bones have been assembled into 15 partial skeletons, of what have been called Homo Naledi – a new hominin species, which could either be one of the earliest Homo species and a precursor to modern humans. Or it could be like the Hobbit - Homo floresiensis, a redundant branch on the human evolutionary tree. The bones have yet to be dated, but the anthropological features suggest a small-brained, human-like creature. The most intriguing thing is where they were found and why in such numbers? Some think it could be a burial chamber and if these Naledis are very ancient, this could be one of the earliest examples of ritualistic behaviour in humans.
It used to be thought that the thing that made humans so special was that we had language and culture. But more and more examples of possible ‘culture’ in animals is being discovered. When we talk about culture we mean – it is something, such as a behaviour, that is socially learned and that it is a group behaviour. We know that whales are social and vocal creatures, so it stands to reason that scientists at Dalhousie University in Canada would want to see if they exhibit some form of culture. They studied large groups of female Sperm whales and found that even those that were unrelated in the group used the same patterns of calls. Similar to dialects in human language, different groups of whales used different patterns of clicks, or codas, to communicate things like where food is or look out for predators and to bond with each other. Clever modelling has ruled out any genetic or geographical reasons for the shared language, which leaves a form of cultural learning as the obvious reason.
Toxic Mercury Cycling in Sea Creatures
It has long been known that heavy metals, such as mercury are very difficult to get rid of once they enter the marine ecosystem. They are ‘biomagnified’ or ‘bio-accumulate’ up the food chain. Mercury typically starts out from man-made processes like coal burning or mining, or naturally from forest fires. It is rapidly converted to a toxic organic compound - methyl mercury - by bacteria in the environment. From this, the mercury then gets into the food chain, so the microscopic zooplankton have tiny amounts of the neurotoxin, but they are eaten in quantity by the little fish, increasing the concentration of the metal, which is stored in the body. Then the bigger fish eat the little fish and the pattern continues right up to the top ocean predators like swordfish, sharks, seals and sea lions. And because it is a toxin it is an issue for us and other animals when it is eaten. Through this fascinating process, the concentration of mercury can be biomagnified 1–10 million fold. But a new study in the journal PNAS this week shows that the route of the poisonous Mercury is not just bottom up, it is top down as well. Hair moulted off in huge quantities by colonies of seals, could be returning the mercury back into the marine ecosystem.
(Photo caption: The skeleton of Homo naledi, a newly discovered human ancestor is displayed during the unveiling of the discovery on September 10, 2015 in Maropeng © Stefan Heunis/AFP/Getty Images)
Presenter: Jack Stewart
Producer: Fiona Roberts