Weather forecasts from alien worlds are in – and it’s wild out there

Weather forecasts from alien worlds are in – and it’s wild out there

We have seen violent winds, clouds of glass and ruby hailstones. In fact, weather on exoplanets can be so extreme that it can make or break their habitability

Sam PeetBy Ryan MacDonald
I HAVE met my nemesis many times, but one occasion sticks in my memory. I had just started a PhD in astronomy at the University of Cambridge, and was due to use their largest telescope for the first time. This instrument was capable of seeing distant nebulae or the ice caps of Mars in detail, and I was pretty excited. But before I reached the building, the sky clouded over. I saw nothing that night.
Clouds have been astronomers’ worst enemy ever since we began observing the night sky. They are why our best telescopes are on mountaintops that peek above their pillowy shapes, with users having to forsake comforts such as family, friends, convenience stores and reasonable quantities of air to breathe.
It seems astronomers on planets circling other stars would be similarly inconvenienced. As we have spied more and more exoplanets from Earth, we have learned that they, too, have clouds. At first these alien clouds seemed an annoying barrier to our penetrating a planet’s atmosphere. But they have turned out to be a gateway to understanding a neglected factor in whether a world is amenable to life: its weather.
Astronomers suspected for centuries that other stars had their own planets, but it wasn’t until the early 90s that we unearthed evidence of them. The first exoplanet orbiting a sun-like star was found when two Swiss astronomers, Michel Mayor and Didier Queloz, monitored one called 51 Pegasi for more than a year. They noticed that its light became redder, then bluer, in a cycle lasting about four days. It meant the star …

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The Kepler spacecraft is dead but its planet-hunting legacy lives on

The Kepler spacecraft is dead but its planet-hunting legacy lives on

NASA/JPL-Caltech/T. PyleBy Daniel Cossins
SO LONG, Kepler, and thanks for all the alien worlds. The most prolific planet-spotter ever built has shut down for good, leaving astronomers to reflect on an era of unprecedented discovery.
On 30 October, NASA confirmed that, after almost a decade of service, the Kepler Space Telescope had finally run out of fuel. This means it can no longer reorient itself to point at stars or beam data back to Earth. It will spend its retirement in eternal orbit around the sun, gradually moving further away from home. But Kepler’s legacy isn’t likely to fade.
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“It confirmed beyond doubt what we’d all been hoping, which is that planets are common in the galaxy,” says Joshua Winn, an astronomer at Princeton University. In the process, it transformed our understanding of the cosmos. We now know that nearly every star in the sky hosts its own collection of alien worlds, and that many of those solar systems are nothing like our own.
When Kepler launched in 2009, we had spotted just 300 planets outside of our solar system. It has since identified some 2300 more and thousands await confirmation. Of all the exoplanets we have found, roughly 70 per cent were spotted by Kepler, which searched a small patch of sky for tell-tale dips in the brightness of stars as alien worlds passed in front them, known as transits.
“We now know that pretty much every star in the sky hosts its own collection of alien worlds”
The numbers are impressive. What really changed our perspective, however, is the incredible diversity of planetary systems among the haul, and the surprises they contained. We saw gas giants and small, rocky worlds orbiting their stars closer than we thought possible; planets orbiting two suns, like Tatooine from Star Wars; and planets that almost share the same orbit, which should be a recipe for disaster.
“Kepler really pulled back the curtain to reveal all sorts of weird and wonderful systems that might eventually help us to understand the process of planet formation,” says Winn.
It also taught us a crucial lesson about where to look for worlds that could harbour life. Its mission was to search for Earth-like planets in the habitable zones, where conditions are favourable for life, around sun-like stars. It found a few – 30 at the last count – but it turns out that potentially habitable worlds are more common around cooler, smaller red dwarf stars.
A hallmark of these colder stars is that their habitable zones are much closer in, which means planets residing within that sweet spot pass their star more often. That makes it easier to find and study them, and explains why some astronomers have now shifted their focus to red dwarfs.
“Kepler laid the groundwork for that, and for all the new things on the horizon now,” says Courtney Dressing at the University of California, Berkeley.
NASA has already launched Kepler’s successor, the Transiting Exoplanet Survey Satellite, which will scan most of the sky, taking in at least 200,000 nearby stars. Then there are several ground-based observatories, including SPECULOOS in Chile’s Atacama desert, which has had its sights trained on 500 ultra-cool dwarfs since December 2017. Its prototype discovered seven rocky planets around a star called TRAPPIST-1, three of which sit in the habitable zone.
“The advantage of the planets SPECULOOS is finding is that atmospheric investigations will be possible,” says team member Amaury Triaud at the University of Birmingham, UK. We can already see some weather on alien worlds (see “Weather forecasts from alien worlds are in – and it’s wild out there”), but not in much detail. SPECULOOS and other new observatories like the James Webb Space Telescope will let us learn more about the conditions on other planets – and determine if any of them might be conducive to life.
This article appeared in print under the headline “Farewell to Kepler, finder of worlds”

More on these topics: astronomyKepler telescopeplanetsstars
Read More

The Kepler spacecraft is dead but its planet-hunting legacy lives on

The Kepler spacecraft is dead but its planet-hunting legacy lives on

NASA/JPL-Caltech/T. PyleBy Daniel Cossins
SO LONG, Kepler, and thanks for all the alien worlds. The most prolific planet-spotter ever built has shut down for good, leaving astronomers to reflect on an era of unprecedented discovery.
On 30 October, NASA confirmed that, after almost a decade of service, the Kepler Space Telescope had finally run out of fuel. This means it can no longer reorient itself to point at stars or beam data back to Earth. It will spend its retirement in eternal orbit around the sun, gradually moving further away from home. But Kepler’s legacy isn’t likely to fade.
Advertisement

“It confirmed beyond doubt what we’d all been hoping, which is that planets are common in the galaxy,” says Joshua Winn, an astronomer at Princeton University. In the process, it transformed our understanding of the cosmos. We now know that nearly every star in the sky hosts its own collection of alien worlds, and that many of those solar systems are nothing like our own.
When Kepler launched in 2009, we had spotted just 300 planets outside of our solar system. It has since identified some 2300 more and thousands await confirmation. Of all the exoplanets we have found, roughly 70 per cent were spotted by Kepler, which searched a small patch of sky for tell-tale dips in the brightness of stars as alien worlds passed in front them, known as transits.
“We now know that pretty much every star in the sky hosts its own collection of alien worlds”
The numbers are impressive. What really changed our perspective, however, is the incredible diversity of planetary systems among the haul, and the surprises they contained. We saw gas giants and small, rocky worlds orbiting their stars closer than we thought possible; planets orbiting two suns, like Tatooine from Star Wars; and planets that almost share the same orbit, which should be a recipe for disaster.
“Kepler really pulled back the curtain to reveal all sorts of weird and wonderful systems that might eventually help us to understand the process of planet formation,” says Winn.
It also taught us a crucial lesson about where to look for worlds that could harbour life. Its mission was to search for Earth-like planets in the habitable zones, where conditions are favourable for life, around sun-like stars. It found a few – 30 at the last count – but it turns out that potentially habitable worlds are more common around cooler, smaller red dwarf stars.
A hallmark of these colder stars is that their habitable zones are much closer in, which means planets residing within that sweet spot pass their star more often. That makes it easier to find and study them, and explains why some astronomers have now shifted their focus to red dwarfs.
“Kepler laid the groundwork for that, and for all the new things on the horizon now,” says Courtney Dressing at the University of California, Berkeley.
NASA has already launched Kepler’s successor, the Transiting Exoplanet Survey Satellite, which will scan most of the sky, taking in at least 200,000 nearby stars. Then there are several ground-based observatories, including SPECULOOS in Chile’s Atacama desert, which has had its sights trained on 500 ultra-cool dwarfs since December 2017. Its prototype discovered seven rocky planets around a star called TRAPPIST-1, three of which sit in the habitable zone.
“The advantage of the planets SPECULOOS is finding is that atmospheric investigations will be possible,” says team member Amaury Triaud at the University of Birmingham, UK. We can already see some weather on alien worlds (see “Weather forecasts from alien worlds are in – and it’s wild out there”), but not in much detail. SPECULOOS and other new observatories like the James Webb Space Telescope will let us learn more about the conditions on other planets – and determine if any of them might be conducive to life.
This article appeared in print under the headline “Farewell to Kepler, finder of worlds”

More on these topics: astronomyKepler telescopeplanetsstars
Read More

Weather forecasts from alien worlds are in – and it’s wild out there

Weather forecasts from alien worlds are in – and it’s wild out there

We have seen violent winds, clouds of glass and ruby hailstones. In fact, weather on exoplanets can be so extreme that it can make or break their habitability

Sam PeetBy Ryan MacDonald
I HAVE met my nemesis many times, but one occasion sticks in my memory. I had just started a PhD in astronomy at the University of Cambridge, and was due to use their largest telescope for the first time. This instrument was capable of seeing distant nebulae or the ice caps of Mars in detail, and I was pretty excited. But before I reached the building, the sky clouded over. I saw nothing that night.
Clouds have been astronomers’ worst enemy ever since we began observing the night sky. They are why our best telescopes are on mountaintops that peek above their pillowy shapes, with users having to forsake comforts such as family, friends, convenience stores and reasonable quantities of air to breathe.
It seems astronomers on planets circling other stars would be similarly inconvenienced. As we have spied more and more exoplanets from Earth, we have learned that they, too, have clouds. At first these alien clouds seemed an annoying barrier to our penetrating a planet’s atmosphere. But they have turned out to be a gateway to understanding a neglected factor in whether a world is amenable to life: its weather.
Astronomers suspected for centuries that other stars had their own planets, but it wasn’t until the early 90s that we unearthed evidence of them. The first exoplanet orbiting a sun-like star was found when two Swiss astronomers, Michel Mayor and Didier Queloz, monitored one called 51 Pegasi for more than a year. They noticed that its light became redder, then bluer, in a cycle lasting about four days. It meant the star …

Read More

Einstein was wrong: Why ‘normal’ physics can’t explain reality

Einstein was wrong: Why ‘normal’ physics can’t explain reality

The most ambitious experiments yet show that the quantum weirdness Einstein famously hated rules the roost – not just here, but across the entire universe

Dan BejarBy Anil Ananthaswamy
IT WAS Dominik Rauch’s birthday, and he was 2300 metres up a mountain in the Canary Islands when a freak winter storm nearly wrecked his PhD. It could have been worse. A few hundred metres away, his colleagues only just managed to scramble out as the wind picked up their aluminium-framed office container and slammed it against the dome of a nearby telescope, just above a steep drop.
“Nobody was hurt,” says Rauch. “We were pretty happy.” But the crystal they planned to use to prise out reality’s secrets was broken beyond repair.
Their experiment atop the Roque de los Muchachos on the Spanish island of La Palma was just the latest and most ambitious of many that have probed quantum mechanics, the inscrutable theory that describes nature’s most basic workings. With six telescopes, oodles of delicate optical equipment and the light emitted by galaxies billions of years ago, they aimed to test an assertion championed by Einstein: that the weirdness of quantum mechanics is just a cover for some deeper, hidden reality.
And test it not just for here and now, but for almost all time, and across virtually the entire observable universe. If any experiment could break quantum theory, this one could.
When quantum mechanics was formulated almost a century ago, it overturned two particularly cherished assumptions about the world’s workings. First was realism. Unlike classical physics, which says the world exists independently of observers and observations, quantum theory strongly implies that reality does not exist, or at least cannot be meaningfully described, until it is observed.
The second problem was “non-locality”. This …

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Our best planet-hunting telescope has come to the end of its mission

Our best planet-hunting telescope has come to the end of its mission

The Kepler Space Telescope’s planet-hunting days are overNASABy Leah CraneThe Kepler Space Telescope’s planet-hunting days are over. NASA announced on 30 October that the spacecraft has run out of fuel and will soon be shut down completely.
Since its launch in 2009, the observatory has found more than 2600 confirmed planets beyond our solar system and many more exoplanet candidates that have yet to be confirmed. Kepler worlds account for about 70 per cent of the total exoplanets we’ve confirmed.
“Before Kepler, we didn’t know if planets were common or rare in our galaxy,” says NASA astrophysics division director Paul Hertz. Now we know that there is a diverse abundance of planets, both similar and different to those in our solar system. “Because of Kepler, what we think about our place in the universe has changed.”
Its original mission was set to last only three and a half years, but despite the failure of two reaction wheels used for pointing the spacecraft in 2012 and 2013, it has been operating for more than nine and a half years.

The end of Kepler is not unexpected – the craft has been intermittently in sleep mode since late September due to trouble pointing it accurately. These issues were probably related to the low levels of fuel that have now run out completely.
“We collected every bit of possible science data and returned it all to the ground safely,” says Kepler system engineer Charlie Sobeck. “We didn’t have a drop of fuel left for anything else.” Now the team will power down Kepler and leave it to float in orbit around the sun, at a safe distance from Earth. Researchers will continue to comb through the data Kepler captured.
The Transiting Exoplanet Survey Satellite (TESS) was launched in April 2018 and has already begun to take on the mantle of Earth’s planet-hunter. Over the course of its lifetime, TESS is expected to follow up on the Kepler planets that have not yet been confirmed and find more than 20,000 new worlds.

More on these topics: astronomyKepler telescopeNASA
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Weather forecasts from alien worlds are in – and it’s wild out there

Weather forecasts from alien worlds are in – and it’s wild out there

We have seen violent winds, clouds of glass and ruby hailstones. In fact, weather on exoplanets can be so extreme that it can make or break their habitability

Sam PeetBy Ryan MacDonald
I HAVE met my nemesis many times, but one occasion sticks in my memory. I had just started a PhD in astronomy at the University of Cambridge, and was due to use their largest telescope for the first time. This instrument was capable of seeing distant nebulae or the ice caps of Mars in detail, and I was pretty excited. But before I reached the building, the sky clouded over. I saw nothing that night.
Clouds have been astronomers’ worst enemy ever since we began observing the night sky. They are why our best telescopes are on mountaintops that peek above their pillowy shapes, with users having to forsake comforts such as family, friends, convenience stores and reasonable quantities of air to breathe.
It seems astronomers on planets circling other stars would be similarly inconvenienced. As we have spied more and more exoplanets from Earth, we have learned that they, too, have clouds. At first these alien clouds seemed an annoying barrier to our penetrating a planet’s atmosphere. But they have turned out to be a gateway to understanding a neglected factor in whether a world is amenable to life: its weather.
Astronomers suspected for centuries that other stars had their own planets, but it wasn’t until the early 90s that we unearthed evidence of them. The first exoplanet orbiting a sun-like star was found when two Swiss astronomers, Michel Mayor and Didier Queloz, monitored one called 51 Pegasi for more than a year. They noticed that its light became redder, then bluer, in a cycle lasting about four days. It meant the star …

Read More

Einstein was wrong: Why ‘normal’ physics can’t explain reality

Einstein was wrong: Why ‘normal’ physics can’t explain reality

The most ambitious experiments yet show that the quantum weirdness Einstein famously hated rules the roost – not just here, but across the entire universe

Dan BejarBy Anil Ananthaswamy
IT WAS Dominik Rauch’s birthday, and he was 2300 metres up a mountain in the Canary Islands when a freak winter storm nearly wrecked his PhD. It could have been worse. A few hundred metres away, his colleagues only just managed to scramble out as the wind picked up their aluminium-framed office container and slammed it against the dome of a nearby telescope, just above a steep drop.
“Nobody was hurt,” says Rauch. “We were pretty happy.” But the crystal they planned to use to prise out reality’s secrets was broken beyond repair.
Their experiment atop the Roque de los Muchachos on the Spanish island of La Palma was just the latest and most ambitious of many that have probed quantum mechanics, the inscrutable theory that describes nature’s most basic workings. With six telescopes, oodles of delicate optical equipment and the light emitted by galaxies billions of years ago, they aimed to test an assertion championed by Einstein: that the weirdness of quantum mechanics is just a cover for some deeper, hidden reality.
And test it not just for here and now, but for almost all time, and across virtually the entire observable universe. If any experiment could break quantum theory, this one could.
When quantum mechanics was formulated almost a century ago, it overturned two particularly cherished assumptions about the world’s workings. First was realism. Unlike classical physics, which says the world exists independently of observers and observations, quantum theory strongly implies that reality does not exist, or at least cannot be meaningfully described, until it is observed.
The second problem was “non-locality”. This …

Read More