Exoplanets Galore: Celebrating 6,000 Discoveries and Exploring Venus

This is Spacetime Series twenty eight, Episode one hundred and fifteen, for broadcast on the twenty fourth of September twenty twenty five. Coming up on space Time, the exoplanet count passes six thousand, the coding Venus's mysterious surface, and the growing tale of interstellar comet three I Atlas. All that and more coming up on Spacetime. Welcome to space Time with Stuart Gary. Astronomers have just confirmed their six thousandth exoplanet, that is, a planet orbiting a star other than the Sun. The new milestone highlights the accelerating redd of discoveries made in the three decades since the first exoplanet, the hot Jubiter fifty one Pergasi, was detected way back in nineteen ninety five. Confirmed planets are added to the count on a rolling basis by astronomers around the world, so there's not a single planet which is actually considered as the six thousandth entry. The numbers monitored by NASA's Exoplanet Science Institute, which is based at Caltech in Pasadena, California. As well as the six thousand confirmed exoplanets, there are more than eight thousand additional candidate planets still await In confirmation, NASA's Astrophysics Division Acting Director Shawn Dommigall Goldman says the historic milestone represents decades of cosmic exploration that's completely changed the way humanity sees the night sky. Instead of just seeing the stars up there, we now know there are planets orbiting those stars. Still, although researchers think there are probably billions of planets up there in the Milky Way galaxy, finding them remains a challenge. In addition to discovering many individual planets with fascinating characteristics, as the total number of exoplanets climbs, astronomers are also able to see how the planetary population compares to planets in our own Solar System. For example, while our Solar System hosts an equal number of terrestrial or rocky planets compared to gas and ice giants, rocky planets appear to be far more common around other stars, and astronomers have also found a range of planets entirely different from anything sinin our Solar System. Of course, there are the Jupiter sized planets known as hot jupiters gas giants whose orbits are closer to their host stars. The Mercury's orbit is to the Sun. Then there are planets that orbit two stars, rogue planets wandering through space not orbiting any star at all, planets orbiting dead stars, planets covered in lava, some with the density of styrofoam, and others with clouds made of gemstones. Each of the different types of planets discovered gives astronomers new information about the conditions under which planets can form, and ultimately how common planets like the Earth might be and where scientists should be looking for them. But despite the thousands of discoveries now made, fewer than one hundred exoplanets have actually been directly imaged. That's because most planets are so faint they get lost in the bright glare from their parents' star, and the other four methods of planetary detection are all indirect. With the transit method, for example, astronomers look for a start to dim for a short period as an orbiting planet passes in front of it to account for the possibility that something other than an exoplanet's responsible for a particular signal. Most exoplanet candidates need to be confirmed by follow up observations, often using additional telescopes that takes up time. Then there's the wobble method, where the massive an orbiting planet causes its host star to slightly wobble off center, something which can be picked up by the star's Doppler shift. The rate of exoplanet discoveries has been accelerating in recent years. The database reached five thousand confirmed exo planets just three years ago, and this trend seems likely to continue. In fact, astronomers expect to receive thousands of new exoplanetary candidates thanks to the European Space Agencies GUY emission, which finds planets through a technique called astrometry. And also, of course, there's NASA's upcoming Nancy Grace Roman Space Telescope, which will discover thousands of new exoplanets, primarily through a technique called gravitational microlensing. At NASA, the future of exoplanet science will emphasize finding rocky planets similar to the Earth, and then studying their atmosphere for biosignatures, that is, any characteristic element, molecule, substance of feature which can be used as evidence of past or present life. NASA's Web Space Telescope has already analyzed the chemistry of more than one hundred exoplanetary atmospheres, but studying the atmospheres of planets the size and temperature of the Earth will require new technology. Specifically, astronomers need better tools to block out the glare of the star of the planet's orbiting and in the case of a small Earth like planet, that glare will be significant. Put it this way, the Sun is about ten billion times brighter than the Earth, and that's more than enough to drown out our home planet's light if it were being viewed by a distant observer. NASA currently has two main initiatives to try and overcome this hurdle. There's the Nazi Grace Roman Space Telescope. It'll carrier technology demonstration instrument called the Roman Chronograph that will test new technologies for blocking starlight and making faint planets more visible. At its peak performance, the coronagraph should be able to directly image a planet the size and temperature of Jupiter orpening a star just like our Sun and at a similar distance from that star. With its microlensing survey and coronographic observations, Nazi Grace Roman will reveal new details about the diversity of planetary systems, showing how common they are, and how many are like our own Solar system across the galaxy. Of course, additional advances in coronagraph technology will still be needed in order to build a coronagraph that can detect a planet the size of the Earth, and NASA is working on the concept for just such a mission, currently named the Habitable World's Observatory. This report from nass A TV. The stars above, what secrets do they keep? One of our biggest questions has always been are we alone? We've now discovered thousands of planets beyond our solar system, but how many of those distant worlds have the conditions for life as we know it? How many have water, vapor, a beacon indicating that oceans might be present, how many of gases like oxygen and methane possible signs of life itself, and of those which might truly have life. After decades of asking, a future NASA telescope could bring us the answers. The Habitable World's Observator is a future mission designed in the tradition of the Hubble and web space telescopes. It will use its unique and sensitive eyes to see planets like our own hiding in the light of their distant stars. Astronomers could then point to the Mighty Space Observatory to the most promising planets, those that may hold liquid water. With the help of its chronograph instrument, which blocks out the dazzling starlight, the telescope will look for undiscovered Earth sized planets in the star's habitable zone where liquid water could exist. The light from each planet will be split into a vibrant spectrum of colors, revealing clues to the chemical signatures we seek. From there, we can attempt to discover if a planet's atmosphere contains water, and from there other signals like oxygen releasing. Should all these signs a lie, the habitable world's observatory would delve deeper to reveal other hidden cools of life. With further study, we could find signs of sprawling oceans and rugged continents, and if signs of life are revealed, keep a watchful eye for changes. Over time, this magnificent observatory could discover dozens of worlds akin to our own. In its first five years. The telescope will gather data on a wide variety of worlds, placing our own solar system in the context within the grand tapestry of existence, and the Habitable World's Observatory will, like the other great cosmic watchers Hubble, Chandra, Spitzer, Web and SMO Roman, also conduct a wide range of revolutionary observations of our cosmos, improving our understanding of how our universe led to potentially habitable worlds. Thus, the Habitable World's Observatory will help us embark on a quest as grand as any to tell the story of life in the cosmos and whether or not we are alone. This space time still to calm. Decoding Venus's mysterious surface and the growing tale of interstellar comet pre I Atlas or that and more still to come on space time, Scientists trying to understand the weird surface features of the planet Venus may finally have come up with an explanation for at least some of this strange world's geography. Venus's surface is pot marked with round crownlike features known as corone. These more or less circular structures can look like terraced hills pushed upwards by heat energy, or like collapsi FLEs shrunken as supporting materials beneath them cool off and contract, and these weird features, which can vary in size abap to tenfold are unlike anything said on Earth. Now are reporting. The Journal of the Proceedings of the National Academy of Sciences suggest that corone are most likely by plumes of magma trying to burst through the planet's crust. That studies lead author Meddling Curve from Script's Oceanography says, one value of studying Venus is understanding what's happened there, which makes it unable to support biological life while life flourishes here on its sister planet Earth. Venus is the closest planet to the Earth. The two worlds are roughly the same size. They were formed out of the same material and the same part of the Solar System and under similar conditions. Yet while Earth has become a habitable world with abundant liquid water and life, Venus has become a hellish landscape with vast laval planes, surface temperatures can reach more than four hundred and sixty degrees celsius, and a thick come dark side atmosphere where pressures are some ninety nine times heavier than that at sea level on Earth. Thanks to a vast and at wide eighty kilometer a thick blanket of clouds, which acts like the lid of a pressure cooker. Now, like Earth, it does rain on Venus, but the rain isn't water, It's sulfuric acid, and metallic snow covers the Venusian mountain peaks. Even stranger, Venus rotates backwards, with the sun rising in the west and setting in the east. A day on this weird world lasts some two hundred and forty three earth days, which is longer than a Venuzian year, which takes some two hundred and twenty five earth days. To reach their conclusions of this new study, the authors map the paths of bursts of magmatic energy pushing outwards from Venus' core, some three thousand kilometers below the crust. Unlike Earth, which has moving tectonic plates caused by the convection of heat from deep below, Venus has just a single, rigid crust covering its entire surface, so heat has no way to escape. Hot upwellings like the blobs that rise in a lava lamp can push through from the core, creating massive two thousand kilometer wide volcanic structures, But many of these hot channels of magnet don't have enough energy to punch through the crust, so when they approach the surface, say six hundred kilometers below, by a layer in the mantle which forms due to changing crystal structures in the rock, creating what the author's term a glass ceiling effect. After some of these hot rocks are blocked, even smaller blobs can rise up towards the surface from this shallower layer. And it's these smaller blobs which may form the abundant small corone features often seen scattered across the Venetian surface. This is space time still to come the growing tail of interstellar Comet three Eye Atlas, and later in the Science report, a new study confirms that daylight savings really is unhealthy for you. All that and more still to come on space time, astronomers have obtained a striking new image of the growing tail of the interstellar comet three Eye Atlas. The observations are revealing what is now a prominent tale and glowing coma from this rare celestial visitor. It's also providing new scientific spectroscopic measurements, allowing scientists to get a better idea of its composition. To do this, the authors use the Gemini Multi object spectrograph on the Gemini South Telescope in Chile. The observations uncovered a broad coma that's the cloud of gas and dust that forms around the comet's icy nucleus as it gets closer to the Sun. They also saw a tail spanning some one one hundred and twentieth of a degree across the sky, pointing away from the Sun. Now. While these features were there before, they now significantly more extended than they appeared in earlier images of the comet, and that shows that comet three eye Atlas has become more active. It's traveling through the inner Solar System getting closer to the head of the Sun. The comet was first detected back on July the first by the Atlas Asteroid Terrestrial Impact LAST Alert system. The new observations suggest that the dust and ice of three I Atlas are broad, similar to those of comets from our Solar system, and that hints at shared processes for forming planetary systems around other stars. The observations examine the comet spectra, which provides clues about its composition and chemistry, as well as the size of dust particles in the coma, but the growth of the tail also suggests a change in the particles from previous Gemini images. Interstellar comets are extraordinarily rare. Three Eye Outlas is only the third confirmed example, after Comet one eye A mal Maa back in twenty seventeen and Comet two I BORISEV in twenty nineteen. Unlike comets from our solar system, which are bound of the Sun, three Eye Outlas is traveling on a hyperbolic orbit that will eventually carry it back out into interstellar space, but its brief passage through our solar system gives astronomers a once in a lifetime opportunity to study material that formed around a distant star. The comet's about to disappear behind the Sun, but it will re emerge in November, where more observations will be made. Needless to say, well keep you informed. This is space time, and time out to take another brief look at some of the other stories making US and science this week with a science report. Every spring, Americans and most Australians beautifully adjust their clocks forward to daylight savings time, and every autumnal fall they adjust them back to standard time. The problem is, no one really seems very happy about it. This buying your time shift is not only inconvenient, it's also known to be acutely bad for human health, and it's been linked to heart attacks and fatal traffic accidents in the ensuing days. Now, a study by Stanford Medicine researchers finds there are longer term hazards as well and better alternatives. The authors compared how three different time policies sticking with a permanent standard time, permanent daylight savings time, and the current biandle shifting, could affect people's circadian rhythms and in turn their health. The authors found that either permanent standard time or permanent daylight savings time would be healthier than the current seasonal wafting, with permanent standard time benefiting the most people. They also found that by modeling light exposure, ccadian rhythm impacts, and health characteristics across the United States, they could estimate that permanent standard time would prevent some three hundred thousand cases of stroke every year, and it would also result in some two point six million fewer people having obesity. The findings, reported in the journal The Proceedings of the National Academy of Sciences, also show that permanent daylight savings time would achieve about two thirds of the same effect. Paleontologists have identified a new species of dinosaur based on a fossil which had been sitting in the museum draw for more than one hundred and twenty five years. Is Scientists from the University of Bristol officially identified the new species Utenetsaurus Xanclodon cambriensis as a large predatory therapod dinosaur. A report in the Journal of the Proceedings of the Geologists Association says the half jaw bone section is some twenty eight centimeters long, so originally the full jaw bone would have been around sixty centimeters in length, corresponding to a dinosaur with a body length of up to seven meters, and this would have been unusually large for a Triassic period therapod, most of which are only about half that size or even smaller. The authors reached their conclusions using modern digital three dimensional scanning techniques to shed new light on the fossil jaw bone, which was dug up in eighteen ninety nine from the Triassic fossil beds of South Wales that had been on display at the National Museum of Wales for many years but had not been correctly identified until now. A new study has shown that artificial intelligence and now determine which young adults need treatment to prevent vision loss. The findings, reported at the forty third Congress of the European Society for Cataract and Refractive Surgery, looked at people with keretacanus, a visual impairment that generally develops in teenagers and young adults, and which tends to worsen in adulthood. The authors used artificial intelligence to assess images of patients eyes, and combined with other data, successfully predicted which patients needed prompt treatment and which could continue with simple monitoring. They found the AI could predict accurately whether a patient's condition would deteriorate or remain stable simply using images and data from just one visit. Using AI, the authors could sort two thirds of patients into a low risk gript that didn't need immediate treatment, and the other one third into a more high risk category who needed prompt attention. In Australia, the final countdowns now underway to the federal government's introduction of what will be a forced digital identification scheme for access to social media. The legislation comes into force on December the tenth now. The government claims it will protect kids under sixty by preventing them from accessing social media and YouTube, but what it really does is that it will force you to prove that you're over sixteen to access those sites. That means supplying often foreign based media companies with your personal details of biometric information, which, despite whateverearances they give you, past experience has proven will end up with your digital ID being traded to other parties or hacked and sold on the dark web. It also provides the government with what they've always wanted, an Australia Card style digital ID for every citizen, allowing politicians and bureaucrats to link your medical records, your driver's license, your tax file number, financial details, your criminal names index if any, as well as addresses and contact information all in the one file. It means the arrival of an or Willian nineteen eighty four style Big Brother, and that's being seen by some as the first step towards the Chinese government style social credit scheme, in which the government will always know what you're doing, where you are, and be able to control what information you get, what services you have access to, even what schools your kids can attend. And again, that's happening right now in China. And before you say that could only happen in a tatalitarian communist dictatorship like China. Well. Similar digital ID records in Canada were used recently the Freeze protesting track drivers access to their own bank accounts, and here in Australia, the spine assurances by the government police use the covid ID passport scheme to track people's whereabouts find out what they've been up to Big Brother indeed, but the public is fighting back. People already started to use more and more VPNs and anonymous browsers such as tor with the details of where we're likely to go. We're joined by technology editor Alex Haharovroyt from tech Advice Start Life. In July this year, the UK had their own age verification system, where people needed to be verifying their age to get online to services like x or Reddit or some of them the pornards, and when that happened, vp and software became the most downloaded on the app store in the UK. And VPNs obviously allow you to change the location that you appear from, and people are clearly using them to bypass these requirements of the Online Safety Act, and that's human nature. Governments want to impose something, and people, like water trying to find the easiest part, are going to flow to things like VPNs to try and get around these particular restrictions. We've seen this in China. I mean, China had VPNs blockages and bands years ago, but people in China still use VPNs to this day to get access to Western services, to get access to Google. And you know, this is just what's going to happen. The government wants to do something to restrict freedom, and people are going to want to do something else to get their freedom back. So we've already seen what happens in other countries and there's no reason to think that exactly the same sort of thing won't happen here in Australia. That's an Exaharov Royd from Tech Advice start live and that's the show for now. 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