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US President Donald Trump at debate: Look at India. The air is filthy - BBC News
President Trump's 'filthy air' remark drew both anger and introspection from Indians.
image copyrightGetty Images image captionPresident Trump described India's air as filthy Indians have reacted to US president Donald Trump describing the air in India, China and Russia as "filthy" during the final election debate. His remarks drew both anger and introspection, with some Indians asking Prime Minister Narendra Modi to take notice. Others agreed that capital Delhi's air was among the most foul in the world. In recent weeks, the city's air quality has turned "severe", with residents complaining of breathing difficulties. India's dreaded pollution season has returned as levels of PM2.5 - dangerous tiny pollutants in the air - in the capital have averaged around 180-300 micrograms per cubic metre in recent weeks, 12 times higher than the WHO's safe limits. "Look at China, how filthy it is. Look at Russia. Look at India. It's filthy. The air is filthy. I walked out of the Paris Accord as we had to take out trillions of dollars and we were treated very unfairly," Mr Trump said talking about the decision to pull out of the Paris Climate Accord which aims to cap global warming "well below" 2C. While his comments about China may not be strictly true, they have resonated with many in India. The air in several cities in northern India is especially bad in winter months - November to February - when several factors, such as farmers burning crop stubble to clear their fields, vehicular and industrial pollution, festive fireworks and low wind speed, contribute to what doctors calls is a "deadly cocktail of poisonous gases". Despite the spikes in air pollution year after year, few concrete steps have been taken to control it. image copyrightGetty Images image captionBurning of crop remains is a major source of air pollution in India On Friday morning, soon after Mr Trump's remarks, "filthy" and "Howdy! Modi" rose to the top of trends on Twitter. The "Howdy, Modi!" event, held in Houston in September 2019 was attended by nearly 50,000 people. It was billed as one of the largest ever receptions for a foreign leader in the US and Mr Trump had called it a "profoundly historic event". A senior leader of India's opposition Congress party, Kapil Sibal, asked if President Trump's remark on India's air was the "fruits of friendship" between the leaders of both the countries and a result of Howdy! Modi. Many pointed to Mr Trump's visit to India in February this year when Mr Modi put on a grand show for his "good friend", complete with songs, dances and a mega reception at a cricket stadium. image copyrightGetty Images image captionNarendra Modi has often described Donald Trump as his "good friend" Following the remarks, many tweeted screenshots of the Air Quality Index in Delhi which has risen to "severe" levels in parts of the city. Writer Kiran Manral tweeted that "air reaches levels of toxicity every single year". "Instead of getting all insulted and upset, can we just take it up as a challenge to clean up our surroundings and our air? So no one can ever dare say that again," she wrote. The spike in the air quality in recent weeks is bad news for India's fight against coronavirus because several studies around the world have linked air pollution to higher Covid-19 case numbers and deaths.
Xbox game streaming 'heading to iPhones' - BBC News
Microsoft is reportedly working on a browser-based version of its game-streaming service.
image copyrightGetty Images Microsoft is planning to bring its Xbox game-streaming service to iPhones next year despite a public row with Apple over the app. The Game Pass streaming service was launched for Android phones last month. But Apple barred the app from its iOS app store, saying all 100 or so games on the service should be listed individually. Microsoft is now developing a web-browser-based version that should work on iPhones. Microsoft employees have been told that a "browser-based solution" is planned for next year, according to reports in both Business Insider and The Verge. "We absolutely will end up on iOS," Xbox head Phil Spencer said, according to both outlets. The streaming service works by offering an interface of games to choose from. Selecting one seamlessly launches the game - assuming the user has a good enough internet connection for the large amount of streaming data needed. But ahead of the planned launch, Apple said its app store rules require that each game is submitted individually for review. Since Microsoft plans to add and remove games on the service constantly, it said it did "not have a path" to bring the service to Apple's iOS. However, Apple released updated guidelines last month which explicitly said that "open internet and web browser apps" are a viable way for game streaming to work, clarifying the rules for Microsoft and other streaming apps. Microsoft now appears to have opted for this route. Other cloud gaming apps have already chosen a similar path. Google Stadia has a web-browser-based option for the PC gaming market, and users have found ways to get it running on iOS through third-party apps that are essentially customised web browsers. And Amazon, which recently announced its Luna game-streaming service, has said it will work on iPhones and iPads at launch through the browser. media captionWATCH: 'Years before game streaming is mainstream' Gaming analyst Piers Harding-Rolls, from Ampere Analysis, said Microsoft's own "evolution" had been expected. "This allows these companies to avoid App Store guidelines which require games subscription services to have all included titles listed on the store separately and to also pay 30% platform fees to Apple for those users subscribing through the store front," he explained. But there are some drawbacks. "A native app is preferable due to performance benefits, integration into system level functionality such as notifications and discoverability within the App Store," he said. Modern web design means that browser apps can have some of the look and feel of real, native apps, he added. "Even so, I consider this a sub-optimal approach and one that would be quickly superseded by a native app if Apple was to change its App Store guidelines for cloud gaming services." Microsoft has not yet responded to a request for comment.
Sir Roger Penrose: The man who proved black holes weren't 'impossible' - BBC News
The UK scientist confessed to being a bit slow in class, but went on to win the Physics Nobel.
By Jonathan AmosBBC Science Correspondent image copyrightANTHONY HOWARTH/SCIENCE PHOTO LIBRARY image captionSir Roger pictured at Oxford in 1980. He has applied his mind across many fields of science If you ever struggled with maths at school, you were in good company. Sir Roger Penrose, who on Tuesday won the Nobel Prize for Physics, would also scratch his head in class. "I was always very slow. I was good at maths, yes, but I didn't necessarily do very well in my tests," the Colchester-born (1931) laureate recalled. "But the teacher realised if he gave me enough time, I would do well. I basically had to do everything by working it out from first principles." Whoever that teacher was and the lessons were in Canada during the war years we have reason to thank him for his patience with the young pupil. Sir Roger would go on to become a star at mathematics, first at University College London and then at Cambridge University, where he pursued his PhD. Sir Roger was interested in topology - the mathematics that describes the properties of geometric objects as they are twisted or stretched. And it was this branch of maths that he would bring to bear on the problem of black holes those extraordinary regions of space where matter has collapsed in on itself, and where gravity is so strong that nothing, not even light, can find a way out. We take for granted today the ability of telescopes to image black holes, or at least their immediate vicinity. And we've become a little blasé, it has to be said, when laser interferometers "hear" yet another pair of black holes bump into each other and merge. And yet, go back just a few decades and the debate around the reality of black holes was a very heated one. This was the cauldron into which Sir Roger jumped when he started applying some of the principles trained up in topology to black holes. Before his seminal 1965 paper, models could describe how these objects might form but they were often dismissed as being idealised situations with perfect symmetry that would be unlikely to occur in the "real world". image copyrightLIGO-VIRGO Collaboration image captionToday we have laser labs where we can "listen" to black holes as they collide in space Sir Roger's breakthrough was to use new approaches - including those topological tools - to show that a singularity, or a state of infinite density and pressure, would be a generic expectation, regardless of symmetry, if you had enough matter clumped together. "I was thinking about the geometry of what goes on (inside these things we now call black holes) - how light rays behave, what they do when they start focusing, and can you stop them focusing, and that kind of thing," he explained. "And I had general arguments which were pure mathematical, topological arguments - not the kind of thing people were using. And it was this idea, which I later called a trapped surface, which is a characterisation of when your collapse had reached a point of no return, roughly speaking, but it didn't depend on symmetry or anything like that. It was just a general characterisation that could tell you that something has gone funny." If astronomers went out and looked in the right places, they would find the evidence, Sir Roger figured. From the remnants of exploded stars to the gargantuan features that lurk at the cores of most galaxies. "While Einstein's general theory of relativity predicts the existence of black holes, Einstein didn't himself believe they really existed," said Prof Jim Al-Khalili, who interviewed Sir Roger for the BBC's The Life Scientific programme in 2016. "Penrose was the first to prove mathematically, in 1965, that they are a natural consequence of relativity theory and not just science fiction." Whenever the general public thinks of black holes, it's often in the context of the late Stephen Hawking. And the pair spent a lot of time in the late 60s and 70s working on the same problems after being brought together by Hawking's PhD supervisor, Dennis Sciama. Their lives ran on parallel tracks for many years. Both came to wider attention through popular science writing. For Hawking, it was A Brief History of Time that enabled him to punch through. And for Sir Roger, it was The Emperor's New Mind and The Road to Reality that built his connection to a lay audience. Although, while Hawking eschewed the use of equations in his books, Sir Roger liked to sprinkle just a few across the pages. "I think it depends what sort of reader you're looking towards; I think my books perhaps attract a certain readership which is a bit different," he conceded. image captionThe giant black hole pictured at the centre of the M87 Galaxy
- A black hole is a region of space where matter has collapsed in on itself
- The gravitational pull is so strong that nothing, not even light, can escape
- Black holes will emerge from the explosive demise of certain large stars
- But some are truly gargantuan, billions of times the mass of our Sun
- How these monsters - found at galaxy centres - formed is unknown
- Black holes are detected from the way they influence their surroundings
- They produce observable gravitational waves as they spiral in to each other
Black hole breakthroughs win Nobel physics prize - BBC News
Three scientists including the UK's Roger Penrose have been awarded the 2020 Nobel Prize in Physics.
Image copyrightNASAImage caption Recent visualisation of a black hole by Nasa Three scientists have been awarded the 2020 Nobel Prize in Physics for work to understand black holes. Roger Penrose, Reinhard Genzel and Andrea Ghez were announced as this year's winners at a news conference in Stockholm. The winners will share the prize money of 10 million kronor (£864,200). Swedish industrialist and chemist Alfred Nobel founded the prizes in his will, written in 1895 - a year before his death. David Haviland, chair of the physics prize committee, said this year's award "celebrates one of the most exotic objects in the Universe". Black holes are regions of space where gravity is so strong that not even light can escape from them. UK-born physicist Roger Penrose, from the University of Oxford, demonstrated that black holes were an inevitable consequence of Albert's Einstein's theory of general relativity. Image caption From L-R: Roger Penrose, Reinhard Genzel, Andrea Ghez "The history of black holes goes way back in time to the end of the 18th Century. Then, through Einstein's general relativity, we had the tools to describe these objects for real," said Ulf Danielsson, a member of the Nobel Committee. But the mathematics of these objects was incredibly complicated to understand, and many researchers believed they were nothing more than mathematical artefacts that existed on paper alone. It took researchers several decades to realise that they could exist in the real world. "That's what Roger Penrose did," said Danielsson. "He understood the mathematics, he introduced new tools and then could actually prove that this is a process you can naturally expect to happen - that a star collapses and turns into a black hole." Penrose, he said, "laid the theoretical foundations to say: these objects exist. You can expect to find them if you go out and look for them". Reinhard Genzel and Andrea Ghez provided the most convincing evidence yet of a supermassive black hole at the centre of our galaxy - the Milky Way. They found that this huge object, known as Sagittarius A*, was tugging on the jumble of stars orbiting it. American Prof Ghez, from the University of California, Los Angeles (UCLA), said: "I'm thrilled to receive the prize and I take very seriously the responsibility of being the fourth woman to win the Nobel prize [in physics]." Reinhard Genzel, from the Max Planck Institute for Extraterrestrial Physics in Garching, Germany, and Ghez used the world's largest telescopes to see through huge clouds of interstellar gas to the centre of the Milky Way. Their discovery stretched the limits of technology and they had to develop new techniques to compensate for distortions to their observations caused by the Earth's atmosphere. Follow Paul on Twitter. Image copyrightESO / M KornmesserImage caption Artwork: Michel Mayor and Didier Queloz have won for their detection of the distant planet 51 Pegasi b 2019 - James Peebles, Michel Mayor and Didier Queloz shared the prize for ground-breaking discoveries about the Universe. 2018 - Donna Strickland, Arthur Ashkin and Gerard Mourou were awarded the prize for their discoveries in the field of laser physics. 2017 - Rainer Weiss, Kip Thorne and Barry Barish earned the award for the detection of gravitational waves. 2016 - David Thouless, Duncan Haldane and Michael Kosterlitz shared the award for their work on rare phases of matter. 2015 - Takaaki Kajita and Arthur McDonald were awarded the prize the discovery that neutrinos switch between different "flavours". 2014 - Isamu Akasaki, Hiroshi Amano and Shuji Nakamura won the physics Nobel for developing the first blue light-emitting diodes (LEDs). 2013 - Francois Englert and Peter Higgs shared the spoils for formulating the theory of the Higgs boson particle. 2012 - Serge Haroche and David J Wineland were awarded the prize for their work with light and matter.
Nasa Wallops launch: Astronauts to test new $23m toilet at space station - BBC News
Astronauts will test the female-friendly toilet before its probable use in a future lunar mission.
Image copyrightNASAImage caption The launch of Northrop Grumman's Antares rocket was delayed on Thursday after technical issues Nasa is to launch a new zero-gravity toilet for testing at the International Space Station (ISS) before its probable use in a future mission to the Moon. The $23m (£17.8m) toilet, which sucks waste from the body, will be sent to the station on a cargo ship. Nasa said the toilet's "vacuum system" was designed for the comfort of female astronauts, unlike previous models. A rocket carrying the cargo ship was supposed to blast off from Wallops Island, Virginia, on Thursday. But the mission was aborted less than three minutes before lift off because of technical difficulties. Another launch attempt is due on Friday evening if engineers can fix the issues that caused Thursday's delay. On board will be the Universal Waste Management System (UWMS), the new titanium space toilet that Nasa says will help astronauts "boldly go" during deep-space missions. The toilet uses a vacuum system to suck waste away from the body in a zero-gravity environment. For privacy, the toilet is located inside a cubicle - just like in a public bathroom on Earth. Image copyrightNASAImage caption The toilet is located inside a stall on the space station Nasa says the toilet represents an upgrade on the current facilities in the US part of the ISS. Weighing 45kg (100lbs) and standing 28in (71cm) tall, the toilet is 65% smaller and 40% lighter than the one currently in use. Designers also gave more consideration to the comfort of female astronauts. "[A] big part of our project was optimising the use of the toilet for the female crew," Melissa McKinley, a Nasa project manager, told the BBC's US partner CBS News. "Nasa spent a lot of time working with the crew members and doing evaluations to improve the use of the commode seat and the urine funnel to make it more accommodating to use by female crew members" she said. Image copyrightNASAImage caption The toilet has been designed with female astronauts in mind These design improvements will be put to the test on the ISS before they are eventually built into Orion capsules that will carry astronauts to the Moon. A successful dry run, in every sense of the term, is what astronauts are hoping for. "Cleaning up a mess is a big deal. We don't want any misses or escapes," Ms McKinley told the Associated Press news agency. Northrop Grumman's Antares rocket will deliver the new toilet as part of a cargo run consisting of science equipment, crew supplies and spare parts. How do space toilets work? Space toilets "use air flow to pull urine and faeces away from the body and into the proper receptacles", according to Nasa. In a video posted to Twitter, Nasa astronaut Jessica Meir described the toilet as a "vacuum system". "So imagine you have a vacuum cleaner and you're sucking things down. You turn on a big fan, so that's pulling everything down inside the toilet," she said. There is a specially shaped funnel for urine and a seat for bowel movements, which can be used simultaneously. "The UWMS seat may look uncomfortably small and pointy, but in microgravity it's ideal," Nasa said. "It provides ideal body contact to make sure everything goes where it should." When sat on the toilet, astronauts can use foot restraints and handholds to keep themselves from floating away. The toilet can process and recycle urine as drinking water for the astronauts. As Ms Meir said, on the ISS "today's coffee is tomorrow's coffee". Faecal waste is not given the same treatment, but Nasa says it is studying this capability. "Just like everything else, going to the bathroom in space is something that you have to get used to," Ms Meir said. You may also be interested in: Media captionBBC science correspondent, Laura Foster, explains how a helicopter, the size of a Chihuahua, will explore Mars
Space station crew woken up to hunt for air leak - BBC News
Ground controllers say the leak is coming from a Russian module on the International Space Station.
Image copyrightNASA Astronauts were woken during the night to continue the hunt for an air leak on the International Space Station (ISS). Crew members have been hunting for the source over several weeks. But the search was stepped up a notch when the size of the leak appeared to grow on Monday; this erroneous reading turned out to have been caused by a temperature change onboard the ISS. Analysis by ground teams traced the leak to the main work area inside a Russian ISS module called Zvezda. This module contains life support equipment for the space station and also houses living quarters for two crew members. Further analysis will be necessary to pinpoint the precise area from which air is escaping. Nasa stressed that it posed no immediate danger to the crew at the current leak rate and will only cause a slight deviation to the crew's ongoing work schedule. Image copyrightNASAImage caption Nasa astronaut and former Navy Seal Chris Cassidy has been leading the search for the leak aboard the ISS Nasa astronaut and station commander Chris Cassidy and Russian space agency (Roscosmos) cosmonauts Anatoly Ivanishin and Ivan Vagner were instructed to move into the Russian segment to collect data at various locations in the Russian modules. One by one, the crew closed hatches between Zvezda's aft and forward sections, along with passageways to other compartments and modules, while using an ultrasonic leak detector to collect data. It was the third time in just over a month that the crew had to isolate themselves on the Russian side, in an attempt to find the growing leak. Throughout the night, pressure measurements were analysed to try to isolate the source of the leak. When the overnight checks were complete, the crew opened hatches once again between the US and Russian segments of the station, resuming their normal activities. It's not the first time ISS crew members have found themselves hunting a leak. In August 2018, astronauts discovered a 2mm drill hole in part of the Russian Soyuz spacecraft docked to the space station at the time. The hole, along with drill marks nearby, appeared to have been a manufacturing defect. Crew members patched it up with epoxy resin for the remainder of the time the Soyuz was docked to the space station.
Coronavirus: NI records highest number of new Covid-19 cases - BBC News
Northern Ireland's department of health reported one further death and 319 positive cases on Saturday.
Image copyrightReutersImage caption There have now been 10,542 positive Covid-19 tests in Northern Ireland NI has recorded its highest daily total for the number of positive Covid-19 tests since the Department of Health rolled out its current testing model. A further 319 were reported on Saturday, bringing the total during the pandemic to 10,542. The department also revealed that one more person has died with the virus, bringing the total number of deaths it has recorded to 578. There are five Covid-19 patients in intensive care units across NI. In the last seven days, 1,396 people have tested positive for the virus. The number of positive cases documented in a 24-hour period surpasses Friday's record of 273. On the same day, the Northern Ireland Statistics and Research Agency (Nisra) reported there were eight coronavirus-linked deaths registered in NI last week. That was one more than the previous week, according to the latest bulletin from the agency. In total, more than 335,000 people have been tested since the pandemic started.
Harley-Davidson to exit world's biggest bike market - BBC News
The iconic motorcycle company is pulling out of India as it struggles to sell its two-wheelers.
Image copyrightGetty ImagesImage caption Actor Jesse Metcalfe riding a Harley Davidson Harley-Davidson is pulling out of India, the world's biggest motorcycle market. The iconic US motorcycle maker is stopping sales and manufacturing operations, it said. Harley's decision comes weeks after Toyota said it wouldn't expand further in India due to the country's high tax regime. The exit is a blow for Indian Prime Minister Narendra Modi's efforts to lure or retain foreign manufacturers. The move involves $75m (£59m) in restructuring costs, around 70 redundancies and the closure of its Bawal plant in northern India. The plant was opened in 2011 but Harley-Davidson has struggled to compete with local brand Hero as well as Japan's Honda. About 17 million motorcycles and scooters are sold each year in India. More setbacks While it is cheaper than many other developing economies, India has proven a tough market to crack for foreign automakers. General Motors pulled out of the country in 2017 while Ford agreed last year to move most of its assets into a joint venture with Indian vehicle giant Mahindra & Mahindra. US President Donald Trump has previously complained about India's high taxes, specifically mentioning the levies placed on Harley-Davidson bikes. India's 100% import tariffs were slashed by 50% but the brand still struggled in the competitive market. But Harley has been suffering its own problems and recorded its first quarterly loss in more than a decade between April and June this year. It has been cutting hundreds of jobs under its new chief executive Jochen Zeitz and focusing on core markets and models. Harley has been looking to grow the brand beyond baby boomers in the US, with smaller models and all-electric versions. Image copyrightGetty ImagesImage caption Dennis Hopper and Peter Fonda ride Harley Davidsons in a scene from the film Easy Rider. Harley History The iconic US motorcycle brand was founded in 1903 and has built a very loyal customer base. It has owners' clubs all over the world. It hit the global stage in 1969 thanks to the classic road movie Easy Rider starring Dennis Hopper, Peter Fonda and Jack Nicholson. Its bikes, nicknamed "hogs", are made in factories in the US, Brazil and Thailand, along with India.
Nasa outlines plan for first woman on Moon by 2024 - BBC News
The US space agency (Nasa) formally outlines its $28bn plan to return astronauts to the Moon by 2024.
Image copyrightNASAImage caption Artwork: Nasa wants to return to the Moon, but this time it wants to stay The US space agency (Nasa) has formally outlined its $28bn (£22bn) plan to return to the Moon by 2024. As part of a programme called Artemis, Nasa will send a man and a woman to the lunar surface in the first landing with humans since 1972. But the agency's timeline is contingent on Congress releasing $3.2bn for building a landing system. Astronauts will travel in an Apollo-like capsule called Orion that will launch on a powerful rocket called SLS. Speaking on Monday afternoon (US time), Nasa administrator Jim Bridenstine said: "The $28bn represents the costs associated for the next four years in the Artemis programme to land on the Moon. SLS funding, Orion funding, the human landing system and of course the spacesuits - all of those things that are part of the Artemis programme are included." But he explained: "The budget request that we have before the House and the Senate right now includes $3.2bn for 2021 for the human landing system. It is critically important that we get that $3.2bn." Artemis: To the Moon and Beyond Image copyrightLockheed MartinImage caption Artwork: astronauts will travel to the Moon in a spacecraft called Orion The US House of Representatives has already passed a Bill allocating $600m towards the lunar lander. But Nasa will need more funds to develop the vehicle in full. Mr Bridenstine added: "I want to be clear, we are exceptionally grateful to the House of Representatives that, in a bipartisan way, they have determined that funding a human landing system is important - that's what that $600m represents. It is also true that we are asking for the full $3.2bn." In July 2019, Mr Bridenstine told CNN that the first woman astronaut to walk on the Moon in 2024 would be someone "who has been proven, somebody who has flown, somebody who has been on the International Space Station already". He also said it would be someone already in the astronaut corps. At the time of this interview, there were 12 active woman astronauts. They have since been joined by five other female Nasa astronauts who graduated from training earlier this year. But it remains unclear whether they can fulfil the criteria in time to fly on the first landing mission in 2024. Image copyrightNASAImage caption The most recent class of astronaut graduates includes six women - five from Nasa and one from the Canadian Space Agency Asked about the timeline for choosing crew members for the Artemis missions, the Nasa chief said he hoped to pick a team at least two years prior to the first mission. However, he said: "I think it's important we start identifying the Artemis team earlier than not... primarily because I think it will serve as a source of inspiration." The new document outlines Phase 1 of the plan, which includes an uncrewed test flight around the Moon - called Artemis-1 - in the autumn of 2021. Nasa's human spaceflight chief Kathy Lueders said that Artemis-1 would last for about a month to test out all the critical systems. She said that demonstration flight would reduce the risk for Artemis-2, which will repeat the trip around the Moon with astronauts. A new test has been added to this mission - a proximity operations demonstration. Shortly after Orion separates from the upper-stage of the SLS rocket - known as the interim cryogenic propulsion stage - astronauts will manually pilot the spacecraft as they approach and back away from the stage. Image copyrightNASAImage caption Artwork: The SLS rocket is on track to make its maiden flight next year This will assess Orion's handling qualities, along with the performance of the spacecraft's hardware and software. Artemis-3 will become the first mission to send astronauts to the lunar surface since Apollo 17 some 48 years ago. Nasa has provided $967m (£763m) to several companies to work on designs for the landing vehicle that will take them there. Later in the decade, the plan calls for Nasa to establish a base for humans, called Artemis Base Camp, that would include the infrastructure needed for long-term exploration of the Moon. Scientists would like to extract water-ice from the lunar South Pole, because it could potentially be used to make rocket fuel on the Moon, at a lower cost than carrying it from Earth. By comparison with Artemis, the Apollo programme in the 1960s and 70s cost upwards of $250bn in inflation-adjusted US dollars. However, the $28bn for this new plan does not include money already spent developing the Orion spacecraft and Space Launch System (SLS) rocket. Follow Paul on Twitter.
Is there life floating in the clouds of Venus? - BBC News
Telescope observations spy a gas high in the atmosphere of Venus that on Earth is made by microbes.
Image copyrightJAXA/ISAS/Akatsuki Project TeamImage caption Planet Venus: The phosphine is detected at mid-latitudes It's an extraordinary possibility - the idea that living organisms are floating in the clouds of Planet Venus. But this is what astronomers are now considering after detecting a gas in the atmosphere they can't explain. That gas is phosphine - a molecule made up of one phosphorus atom and three hydrogen atoms. On Earth, phosphine is associated with life, with microbes living in the guts of animals like penguins, or in oxygen-poor environments such as swamps. For sure, you can make it industrially, but there are no factories on Venus; and there are certainly no penguins. So why is this gas there, 50km up from the planet's surface? Prof Jane Greaves, from Cardiff University, UK and colleagues are asking just this question. They've published a paper in the journal Nature Astronomy detailing their observations of phosphine at Venus, as well as the investigations they've made to try to show this molecule could have a natural, non-biological origin. But for the moment, they're stumped - as they tell the BBC's Sky At Night programme, which has talked at length to the team. You can see the show on BBC Four tonight (Monday) at 22:30 BST. Given everything we know about Venus and the conditions that exist there, no-one has yet been able to describe an abiotic pathway to phosphine, not in the quantities that have been detected. This means a life source deserves consideration. "Through my whole career I have been interested in the search for life elsewhere in the Universe, so I'm just blown away that this is even possible," Prof Greaves said. "But, yes, we are genuinely encouraging other people to tell us what we might have missed. Our paper and data are open access; this is how science works." Media captionHow corrosive is sulphuric acid? Dr William Bains shows Sky At Night's Chris Lintott What exactly has the team detected? Prof Greaves' team first identified phosphine at Venus using the James Clerk Maxwell Telescope in Hawaii, and then confirmed its presence using the Atacama Large Millimeter/submillimeter Array in Chile. Phosphine has a distinctive "absorption line" that these radio telescopes discern at a wavelength of about 1mm. The gas is observed at mid-latitudes on the planet at roughly 50-60km in altitude. The concentration is small - making up only 10-20 parts in every billion atmospheric molecules - but in this context, that's a lot. Image copyrightESO/M.Kornmesser/L.Calcada/NasaImage caption The phosphine molecule is made up of one phosphorus atom and three hydrogen atoms Why is this so interesting? Venus is not at the top of the list when thinking of life elsewhere in our Solar System. Compared to Earth, it's a hellhole. With 96% of the atmosphere made up of carbon dioxide, it has experienced a runaway greenhouse effect. Surface temperatures are like those in a pizza oven - over 400 degrees. Space probes that have landed on the planet have survived just minutes before breaking down. And yet, go 50km up and it's actually "shirtsleeves conditions". So, if there really is life on Venus, this is exactly where we might expect to find it. Image copyrightDETLEV VAN RAVENSWAAY/SPLImage caption Artwork: Venus is envisioned as a hellish world, an unlikely candidate to host life Why should we be sceptical? The clouds. They're thick and they're mainly composed (75-95%) of sulphuric acid, which is catastrophic for the cellular structures that make up living organisms on Earth. Dr William Bains, who's affiliated to the Massachusetts Institute of Technology (MIT) in the US, is a biochemist on the team. He's studied various combinations of different compounds expected to be on Venus; he's examined whether volcanoes, lightning and even meteorites could play a role in making PH3 - and all of the chemical reactions he's investigated, he says, are 10,000 times too weak to produce the amount of phosphine that's been observed. To survive the sulphuric acid, Dr Bains believes, airborne Venusian microbes would either have to use some unknown, radically different biochemistry, or evolve a kind of armour. "In principle, a more water-loving life could hide itself away inside a protective shell of some sorts inside the sulphuric acid droplets," he told Sky At Night. "We're talking bacteria surrounding themselves by something tougher than Teflon and completely sealing themselves in. But then how do they eat? How do they exchange gases? It's a real paradox." Image caption The Soviet probes that landed survived just long enough to radio back a handful of pictures What's been the reaction? Cautious and intrigued. The team emphatically is not claiming to have found life on Venus, only that the idea needs to be further explored as scientists also hunt down any overlooked geological or abiotic chemical pathways to phosphine. Oxford University's Dr Colin Wilson worked on the European Space Agency's Venus Express probe (2006-2014), and is a leading figure in the development of a new mission concept called EnVision. He said Prof Greaves' observations would spur a new wave of research at the planet. "It's really exciting and will lead to new discoveries - even if the original phosphine detection were to turn out to be a spectroscopic misinterpretation, which I don't think it will. I think that life in Venus' clouds today is so unlikely that we'll find other chemical pathways of creating phosphine in the atmosphere - but we'll discover lots of interesting things about Venus in this search," he told BBC News. Dr Lewis Dartnell from the University of Westminster is similarly cautious. He's an astrobiologist - someone who studies the possibilities of life beyond Earth. He thinks Mars or the moons of Jupiter and Saturn are a better bet to find life. "If life can survive in the upper cloud-decks of Venus - that's very illuminating, because it means maybe life is very common in our galaxy as a whole. Maybe life doesn't need very Earth-like planets and could survive on other, hellishly-hot, Venus-like planets across the Milky Way." Image copyrightESOImage caption The phosphine signal was confirmed by the ALMA telescope facility in Chile How can the question be resolved? By sending a probe to investigate specifically the atmosphere of Venus. The US space agency (Nasa) asked scientists recently to sketch the design for a potential flagship mission in the 2030s. Flagships are the most capable - and most expensive - ventures undertaken by Nasa. This particular concept proposed an aerobot, or instrumented balloon, to travel through the clouds of Venus. "The Russians did this with their Vega balloon (in 1985)," said team-member Prof Sara Seager from MIT. "It was coated with Teflon to protect it from sulphuric acid and floated around for a couple of days, making measurements. "We could definitely go make some in-situ measurements. We could concentrate the droplets and measure their properties. We could even bring a microscope along and try to look for life itself." Image copyrightNASA-JPL/CaltechImage caption Artwork: One of the best ways to resolve the uncertainty would be with instrumented balloons The Sky At Night special on this story can be seen at 22:30 on BBC Four, and afterwards on the BBC iPlayer. [email protected] and follow me on Twitter: @BBCAmos