Astronomers Have Discovered Why The Solar System Might Be Shaped Like a Croissant

The possible croissant-like shape of the Solar System. (M. Opher)SPACE


The Solar System exists in a bubble.

Wind and radiation from the Sun stream outwards, pushing out into interstellar space. This creates a boundary of solar influence, within which the objects in the Solar System are sheltered from powerful cosmic radiation.

It’s called the heliosphere, and understanding how it works is an important part of understanding our Solar System, and perhaps even how we, and all life on Earth, are able to be here.

“How is this relevant for society? The bubble that surrounds us, produced by the Sun, offers protection from galactic cosmic rays, and the shape of it can affect how those rays get into the heliosphere,” says astrophysicist James Drake of the University of Maryland.

“There’s lots of theories but, of course, the way that galactic cosmic rays can get in can be impacted by the structure of the heliosphere – does it have wrinkles and folds and that sort of thing?”

Since we’re inside the heliosphere, and its boundary is not actually visible, figuring out its shape is not exactly easy. But it’s not impossible. The two Voyager probes and New Horizons are three spacecraft that have traveled to the far reaches of the Solar System; in fact, the Voyager probes have even traversed the boundary of the heliosphere, and are currently making their way through interstellar space.

With data from these probes, scientists determined last year that the heliosphere could be shaped a bit like a weird cosmic croissant. Now, they have figured out how: neutral hydrogen particles streaming into the Solar System from interstellar space likely play a crucial role in sculpting the shape of the heliosphere.

The team set out to investigate the heliospheric jets. These are twin jets of material that emanate from the Sun’s poles, shaped by the interaction of the solar magnetic field with the interstellar magnetic field. Rather than shooting straight out, though, they curve around, pushed by the interstellar flow – like the points of a croissant. These are the Solar System’s tails.

turbulence solar jetsA reconstruction of the heliosphere showing the jets. (M. Opher/AAS)

These are similar to other astrophysical jets observed in space, and like those other jets, the Sun’s jets are unstable. And the heliosphere, shaped by the Sun, also appears to be unstable. The researchers wanted to know why.

“We see these jets projecting as irregular columns, and [astrophysicists] have been wondering for years why these shapes present instabilities,” explains astrophysicist Merav Opher of Boston University (BU), who led the research.

The team performed computational modeling, focusing on neutral hydrogen atoms – those that carry no charge. We know these stream through the Universe, but not what effect they could have on the heliosphere. When the researchers took the neutral atoms out of their model, suddenly the solar jets became stable. Then they put them back.

“When I put them back in, things start bending, the center axis starts wiggling, and that means that something inside the heliospheric jets is becoming very unstable,” Opher says.

According to the team’s analysis, this occurs because of the interaction of the neutral hydrogen with the ionized matter in the heliosheath – the outer region of the heliosphere. This generates a Rayleigh-Taylor instability, or an instability that occurs at the interface between two fluids of different densities when the lighter fluid pushes into the heavier one. In turn, this produces large-scale turbulence in the tails of the heliosphere.

It’s a clear and elegant explanation for the shape of the heliosphere, and one that could have implications for our understanding of the way galactic cosmic rays enter the Solar System. In turn, this could help us to better understand the radiation environment of the Solar System, outside Earth’s protective magnetic field and atmosphere.

“The Universe is not quiet. Our BU model doesn’t try to cut out the chaos, which has allowed me to pinpoint the cause [of the heliosphere’s instability]…. The neutral hydrogen particles,” Opher says.

“This finding is a really major breakthrough, it’s really set us in a direction of discovering why our model gets its distinct croissant-shaped heliosphere and why other models don’t.”

The research has been published in The Astrophysical Journal.

Scientist predicts Earth will develop rings like Saturn

“Earth is on course to have its own rings. They’ll just be made of junk.” ByShirin Ali | Nov. 23, 2021 seconds of 2 minutes, 44 secondsVolume 20%

Story at a glance

  • NASA says that there are more than 27,000 pieces of space junk being tracked by the Department of Defense.
  • Space junk travels at extremely high speeds, which equals approximately 15,700 mph in low Earth orbit.
  • With a growing commercial space industry, the volume of space junk is expected to grow significantly.

As more and more debris accumulates in space and surrounds Earth’s orbit, one researcher believes our planet will eventually develop rings made completely of space junk.

Jake Abbott, a robotics professor at the University of Utah, told The Salt Lake Tribune that “Earth is on course to have its own rings. They’ll just be made of junk.”

Abbott was part of a team of researchers that published a report last month, which detailed how nonmagnetic space junk can conduct electricity. According to an analysis by The Tribune, Abbott and fellow researchers believed to have found a way by using controlled force and torque to slow spinning objects, move them around and eventually collect them. Abbott believes the findings could relate to collecting space junk orbiting around Earth’s atmosphere.

Space junk, or known as space debris, is a growing problem with NASA reporting that there are more than 27,000 pieces of space junk being tracked by the Department of Defense’s global Space Surveillance Network (SSN) sensors. 

NASA also said that there is likely much more debris in space that’s too small to be tracked but still large enough to threaten human spaceflight and robotic missions. Space debris travels at extremely high speeds — approximately 15,700 mph in low Earth orbit — so even a tiny piece of orbital debris can impact a spacecraft and create big problems.

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With a growing commercial space industry, the volume of space junk is expected to grow significantly. Elon Musk’s space company SpaceX has carried nearly 900 orbital objects to space this year, according to The Verge. Amazon also has plans to send more than 3,000 satellite constellations to Earth’s low-orbit to provide internet broadband services. 

The former Trump administration put together a national orbital debris research and development plan that sought to reduce space junk by recommending the implementation of deliberate spacecraft designs that limit the generation of new space debris. It also recommended improving how the U.S. tracks and characterizes space junk and urged solutions on how to remove space debris and repurpose it for a productive use. 

It’s not clear if the Trump administration’s report was enacted but the problem of space debris continues on, while the likelihood of Earth developing rings made of space junk, similar to those of Saturn, Jupiter, Uranus and Neptune, isn’t completely clear either. 

Some companies are hoping to help address the issue of space junk like Astroscale, according to Forbes. The Japan-based company has begun construction of a prototype spacecraft that will test out strategies in space that remove debris in orbit.

This dead star offers a glimpse of our solar system’s eventual fate

This dead star offers a glimpse of our solar system’s eventual fate

By Ashley Strickland, CNN

Updated 10:57 AM ET, Sat October 16, 2021

See Shatner's emotional remarks after landing

See Shatner’s emotional remarks after landing 02:26A version of this story appeared in CNN’s Wonder Theory newsletter. To get it in your inbox, sign up for free here. Tell us what you’d like to see more of in the newsletter at

(CNN)Space truly is the final frontier.Fifty-five years after the world met Capt. James T. Kirk and his crew on the USS Enterprise, William Shatner was able to boldly go there.

The “Star Trek” actor became the oldest person to ever travel to space. The trip was a blisteringly brief 10 minutes aboard Blue Origin’s New Shepard spacecraft, but Shatner was incredibly moved by the “profound experience” of seeing the “life and nurturing” of Earth.

Current-day scientists are living up to the words spoken by Shatner in the show’s introduction half a century ago: exploring strange new worlds and seeking out new life.

And today, NASA’s Lucy mission lifted off on a quest to understand how our solar system formed 4.5 billion years ago.

Once upon a planet

This illustration shows a Jupiter-like planet orbiting a dead white dwarf star.This illustration shows a Jupiter-like planet orbiting a dead white dwarf star.Our corner of the universe may be in for a rude awakening, but we’ve got 5 billion years to prepare.Researchers observed a giant planet orbiting a white dwarf, or the remains of a dead star, at the heart of our galaxy. It showed what may happen in our solar system when the sun dies.While Saturn and Jupiter will likely survive the violent evolution, it’s a different story for the other planets.


With sea levels steadily on the rise, 50 major coastal cities need to adapt in unprecedented ways to stay afloat, according to new research.The results show striking visual contrasts between the world as we know it today and our underwater future, if the planet warms to 5.4 degrees Fahrenheit (3 degrees Celsius) above preindustrial levels.Use our visual sliders to compare how California’s Santa Monica pier and London’s Buckingham Palace would appear if global warming and sea level rise can’t be stopped. The sight of such iconic places submerged is startling.

Wild kingdom

Italian photographer Stefano Unterthiner captured this image of two reindeer battling for control.Italian photographer Stefano Unterthiner captured this image of two reindeer battling for control.Stunning photos revealing our wonderfully wild world have won in 19 categories of the 2021 Wildlife Photographer of the Year competition.Photographers from 95 countries submitted a record-breaking 50,000 entries, with shots including a gorilla enjoying a rain shower and a tent spider’s web as an auto-rickshaw passed by in India (which was captured by a 10-year-old).And enjoy a peek at the cuter side of wild animals with this litter of adorable newborn cheetahs.Five cubs were born to cheetah mom Rosie Tuesday morning at Virginia’s Smithsonian Conservation Biology Institute. You can watch the feline family via the Cheetah Cub Cam, which features live footage of the den. If you listen closely, you can hear the cubs chirping.

Across the universe

An outburst of cosmic explosions has been traced back to a mysterious repeating fast radio burst in space called FRB 121102. Researchers detected 1,652 bursts over the course of 47 days.Fast radio bursts, or FRBs, are millisecond-long emissions of radio waves in space. This one has been traced to a small dwarf galaxy over 3 billion light-years away.Scientists have yet to determine the actual cause of the flashes, and, naturally, everyone has a theory (greetings, aliens!). But researchers suspect these celestial phenomena as the more likely cause.

We are family

This aerial photo shows the Tel Yavne excavation site, where a massive wine production facility was discovered.This aerial photo shows the Tel Yavne excavation site, where a massive wine production facility was discovered.As humans, it appears we have a long history of indulgences.Archaeologists uncovered a 1,500-year-old wine factory in the Israeli town of Yavne after toiling away at the site for two years. A famous brand of wine from the ancient world was likely made at the world’s largest wine factory from the Byzantine period, they said.Meanwhile, researchers studying fossilized poop discovered that Iron Age Europeans enjoyed blue cheese and beer in their diet.And charred seeds found in a hearth once belonging to hunter-gatherers in Utah suggest humans used tobacco over 12,000 years ago — 9,000 years earlier than previously thought.


You never know what you’ll find:– This “living fossil” creature was found in an incredibly unlikely place for the first time in documented history.– An Australian-made rover will land on the moon in 2026 and collect lunar soil that may contain oxygen, which NASA hopes to extract.

— These carved stone statues were used as garden ornaments — until it was revealed that they were Egyptian relics dating back thousands of years.Like what you’ve read? Oh, but there’s more. Sign up here to receive in your inbox the next edition of Wonder Theory, brought to you by CNN Space and Science writer Ashley Strickland, who finds wonder in planets beyond our solar system and discoveries from the ancient world.

Dropping Oxygen Will Eventually Suffocate Most Life on Earth

(Aaron Foster/The Image Bank/Getty Images)ENVIRONMENT

Enjoy It While You Can:


For now, life is flourishing on our oxygen-rich planet, but Earth wasn’t always that way – and scientists have predicted that, in the future, the atmosphere will revert back to one that’s rich in methane and low in oxygen.

This probably won’t happen for another billion years or so. But when the change comes, it’s going to happen fairly rapidly, the study from earlier this year suggests.

This shift will take the planet back to something like the state it was in before what’s known as the Great Oxidation Event (GOE) around 2.4 billion years ago.

What’s more, the researchers behind the new study say that atmospheric oxygen is unlikely to be a permanent feature of habitable worlds in general, which has implications for our efforts to detect signs of life further out in the Universe.

“The model projects that a deoxygenation of the atmosphere, with atmospheric O2 dropping sharply to levels reminiscent of the Archaean Earth, will most probably be triggered before the inception of moist greenhouse conditions in Earth’s climate system and before the extensive loss of surface water from the atmosphere,” wrote the researchers in their published paper.

At that point it’ll be the end of the road for human beings and most other life forms that rely on oxygen to get through the day, so let’s hope we figure out how to get off the planet at some point within the next billion years.

To reach their conclusions, the researchers ran detailed models of Earth’s biosphere, factoring in changes in the brightness of the Sun and the corresponding drop in carbon dioxide levels, as the gas gets broken down by increasing levels of heat. Less carbon dioxide means fewer photosynthesizing organisms such as plants, which would result in less oxygen.

Scientists have previously predicted that increased radiation from the Sun would wipe ocean waters off the face of our planet within about 2 billion years, but the new model – based on an average of just under 400,000 simulations – says the reduction in oxygen is going to kill off life first.

“The drop in oxygen is very, very extreme,” Earth scientist Chris Reinhard, from the Georgia Institute of Technology, told New Scientist earlier this year. “We’re talking around a million times less oxygen than there is today.”

What makes the study particularly relevant to the present day is our search for habitable planets outside of the Solar System.

Increasingly powerful telescopes are coming online, and scientists want to be able to know what they should be looking for in the reams of data these instruments are collecting.

It’s possible that we need to be hunting for other biosignatures besides oxygen to have the best chance of spotting life, the researchers say. Their study is part of the NASA NExSS (Nexus for Exoplanet System Science) project, which is investigating the habitability of planets other than our own.

According to the calculations run by Reinhard and environmental scientist Kazumi Ozaki, from Toho University in Japan, the oxygen-rich habitable history of Earth could end up lasting for just 20-30 percent of the planet’s lifespan as a whole – and microbial life will carry on existing long after we are gone.

“The atmosphere after the great deoxygenation is characterized by an elevated methane, low-levels of CO2, and no ozone layer,” said Ozaki. “The Earth system will probably be a world of anaerobic life forms.”

The research has been published in Nature Geoscience.

A version of this article was first published in March 2021.

Razor Thin: A New Perspective on Earth’s Atmosphere

Published 2 days ago 

on September 3, 2021

ByCarmen Ang



Earth's Atmosphere

▼ Use This Visualization

Razor Thin: A New Perspective on Earth’s Atmosphere

Earth is the only known planet that sustains life. Its atmosphere provides us with oxygen, protects us from the Sun’s radiation, and creates the barometric pressure needed so water stays liquid on our planet.

But while Earth’s atmosphere stretches for about 10,000 km (6,200 miles) above the planet’s surface, only a thin layer is actually habitable.

This graphic, inspired by Andrew Winter, shows just how small Earth’s “habitable zone” is, using the state of Florida as a point of reference.

Earth’s Like an Onion: It Has Layers

Our planet’s atmosphere is made up of a unique cocktail of gases—roughly 78% nitrogen and 21% oxygen, with trace amounts of water, argon, carbon dioxide, and other gases.

It’s separated into five different layers:

  • Exosphere: The uppermost layer of our atmosphere that melds into outer space.
  • Thermosphere: Begins at around 80 km (50 miles) above sea level and extends to approximately 600 km (372 miles), reaching temperatures as high as 2,000°C (3,600°F).
  • Mesosphere: Around 30 km (19 miles) in range, meteors burn as they pass through this layer, creating “shooting stars.”
  • Stratosphere: Home to the ozone layer, which is responsible for absorbing a majority of the sun’s radiation.
  • Troposphere: The closest layer to ground. It stretches about 7–15 kilometers (5–10 miles) from the surface.

The troposphere makes up approximately 75-80% of the atmosphere’s mass, as it’s where most of the dust, ash, and water vapor are stored. But only a part of this layer is suitable for human life—in fact, the atmosphere’s habitable zone is so small, several mountain ranges extend beyond it.

Reaching Into Earth’s Atmosphere: Extremely High Altitudes

Elevations above 5,500 meters (18,000 ft) are considered extremely high altitude and require special equipment and/or acclimatization in order to survive. Even then, those who choose to venture to extreme heights run the risk of getting altitude sickness.

When it comes to the world’s tallest mountain ranges, the Himalayas are the highest. At their peak, Mount Everest, the Himalayas reach 8,848 m (29,000 ft) above sea level.

Mountain rangeHighest mountainHeightCountries
HimalayasMount Everest8,848 mNepal, China
KarakoramK28,611 mPakistan
Hindu KushTirich Mir7,708 mPakistan
Kongur ShanKongur Tagh7,649 mChina
Daxue MountainsMount Gongga7,556 mChina
Pamir MountainsIsmoil Somoni Peak7,495 mTajikistan
Kakshaal TooJengish Chokusu7,439 mChina, Kyrgyzstan
Nyenchen Tanglha MountainsGyala Peri7,294 mChina
AndesAconcagua6,960 mArgentina
Kunlun MountainsChakragil6,760 mChina

Showing 1 to 10 of 26 entriesPreviousNext

Despite the dangers of extreme altitude, hundreds of mountaineers attempt to climb Mount Everest each year. On Everest, the region above 8,000 m (26,000 feet) is referred to as the “death zone,” and climbers have to bring bottled oxygen on their trek in order to survive.

Life Beyond Earth

Earth is the only known planet with an atmosphere we can survive in. And even on Earth, certain areas are considered dead zones.

But there may be other life forms out in the galaxy that we haven’t discovered. Recent research in The Astrophysical Journal predicts there are at least 36 intelligent civilizations throughout the galaxy today.

So life may very well exist beyond Earth. It just might look a bit different than we’re used to.

Scientists identify 29 planets where aliens could observe Earth

Astronomers estimate 29 habitable planets are positioned to see Earth transit and intercept human broadcasts

The scientists identified 1,715 star systems where alien observers could have discovered Earth in the past 5,000 years by watching it ‘transit’ across the face of the sun. Photograph: c/o Cornell

Ian Sample Science editor@iansampleWed 23 Jun 2021 11.00 EDT

For centuries, Earthlings have gazed at the heavens and wondered about life among the stars. But as humans hunted for little green men, the extraterrestrials might have been watching us back.

In new research, astronomers have drawn up a shortlist of nearby star systems where any inquisitive inhabitants on orbiting planets would be well placed to spot life on Earth.

The scientists identified 1,715 star systems in our cosmic neighbourhood where alien observers could have discovered Earth in the past 5,000 years by watching it “transit” across the face of the sun.

Among those in the right position to observe an Earth transit, 46 star systems are close enough for their planets to intercept a clear signal of human existence – the radio and TV broadcasts which started about 100 years ago.Advertisement

The researchers estimate that 29 potentially habitable planets are well positioned to witness an Earth transit, and eavesdrop on human radio and television transmissions, allowing any observers to infer perhaps a modicum of intelligence. Whether the broadcasts would compel an advanced civilisation to make contact is a moot point.

“One way we find planets is if they block out part of the light from their host star,” said Lisa Kaltenegger, professor of astronomy and director of the Carl Sagan Institute at Cornell University in New York. “We asked, ‘Who would we be the aliens for if somebody else was looking?’ There is this tiny sliver in the sky where other star systems have a cosmic front seat to find Earth as a transiting planet.”

Earthly astronomers have detected thousands of planets beyond the solar system. About 70% are spotted when alien worlds pass in front of their host stars and block some of the light that reaches scientists’ telescopes. Future observatories, such as Nasa’s James Webb Space Telescope due to launch this year, will look for signs of life on “exoplanets” by analysing the composition of their atmospheres.

To work out which nearby star systems are well placed to observe an Earth transit, Kaltenegger and Dr Jackie Faherty, an astrophysicist at the American Museum of Natural History, turned to the European Space Agency’s Gaia catalogue of star positions and motions. From this they identified 2,034 star systems within 100 parsecs (326 light years) that could spot an Earth transit any time from 5,000 years ago to 5,000 years in the future.

One star known as Ross 128, a red dwarf in the Virgo constellation, is about 11 light years away – close enough to receive Earth broadcasts – and has a planet nearly twice the size of Earth. Any suitably equipped life on the planet could have spotted an Earth transit for more than 2,000 years, but lost the vantage point 900 years ago. If there is intelligent life on any of the two known planets orbiting Teegarden’s star, 12.5 light years away, it will be in a prime position to watch Earth transits in 29 years’ time.

At 45 light years away, another star called Trappist-1 is also close enough to eavesdrop on human broadcasts. The star hosts at least seven planets, four of them in the temperate, habitable zone, but they will not be in position to witness an Earth transit for another 1,642 years, the scientists write in Nature.

The findings come as the US government prepares to publish a hotly anticipated report on unidentified flying objects (UFOs). The report from the Pentagon’s Unidentified Aerial Phenomena Task Force, which was set up to gain insights into the nature and origins of unknown aircraft, is not expected to reveal evidence of alien antics, or rule it out.

Prof Beth Biller at Edinburgh University’s Institute for Astronomy, who was not involved in the Nature study, said the work could change how scientists approach Seti, the search for extraterrestrial life. “What was striking to me was how few of the stars within 100 parsecs could have viewed a transiting Earth,” she said.

“The transit method requires a very precise alignment between the transiting planet, its star, and the sun for a given planet to be detectable, so this result is not surprising. Now I am curious about what fraction of the stars in the Gaia catalogue of nearby stars have the right vantage point to detect the Earth via other exoplanet detection methods, such as the radial velocity method or direct imaging!”

A Record-Breaking Flare Has Erupted From The Closest Star to Our Solar System

(NRAO/S. Dagnello)SPACE


Two years ago, our star’s next door neighbor – Proxima Centauri – got a little emotional. It happens from time to time, only this time, the small red star really let go. A storm of fury that breaks its previous records, outdoing anything our own Sun could manage by magnitudes.

Sure, we were eavesdropping, but it’s all in the name of science. Besides, we now have some galactic gossip we’re dying to share – this was not your typical solar eruption.

As far as neighbors go, you could do worse than Proxima Centauri. At a mere 4 light-years (just over 30 trillion kilometers) over the back fence, it’s close enough to keep an eye on without being prone to blowing up in a life-destroying cataclysm.  

That doesn’t mean it’s quiet. Like most hot-tempered red dwarf stars, Proxima Centauri vents its rage every now and then in a brilliant display of radiation, spilling streams of plasma and light out into its system with a manic snapping and rejoining of its magnetic fields.

This is bad news for its host of innermost planets, which periodically cop a roasting that makes it unlikely that any complex organic chemistry on the surface would have remained intact long enough to spark into life.

But for us, watching these outbursts from a safe distance gives insight into the mechanisms of stellar physics. In 2019, astronomers trained nine telescopes around the globe on Proxima Centauri for a marathon 40-hour session.

They weren’t planning on missing any details – using telescopes such as the Australian Square Kilometre Array Pathfinder, the Atacama Large Millimeter/submillimeter Array, and the Transiting Exoplanet Survey Satellite, they listened in on multiple frequencies, from radio to X-ray.

“It’s the first time we’ve ever had this kind of multi-wavelength coverage of a stellar flare,” says astrophysicist Meredith MacGregor from University of Colorado Boulder.

“Usually, you’re lucky if you can get two instruments.”

And oh boy, they weren’t disappointed. Not only did five of their instruments catch sight of the largest flare to be observed in the Proxima Centauri system to date, the signature of the eruption was strange enough to suggest they had an entirely new kind of solar event on their hands.

Back in 2016, astronomers caught a similar superflare, one that could be seen without telescopes.

Though technically bigger, becoming 14,000 times brighter over the span of a few seconds, this more recent activity was largely in the form of wavelengths we can’t see, such as in the ultraviolet and radio parts of the spectrum.

Finding such a strong surge in the radio zone of millimeter range waves was completely unexpected, making this flare really worth paying attention to.

“In the past, we didn’t know that stars could flare in the millimeter range, so this is the first time we have gone looking for millimeter flares,” says MacGregor.  

The timing and energies of the different wavelengths of light in the flare provide astrophysicists with a novel look into the mechanisms behind flare production, adding details to our models.

Knowing that solar flares emit in this part of the spectrum means researchers will be more inclined to train a greater range of instruments on variable stars in the future in the hopes of catching a stray whisper of radiation they missed before.

“There will probably be even more weird types of flares that demonstrate different types of physics that we haven’t thought about before,” says MacGregor.

This won’t be the last tantrum we’ll see Proxima Centauri have, and probably not even the biggest. While this unusual eruption was the largest of the flares seen during the 40-hour window of observations, it wasn’t the only one the researchers saw.

In fact, our tiny neighbor could be in a near constant rage, unleashing its hostility at least once a day. Maybe more.

At least its temper isn’t as bad as AD Leonis, another angry red dwarf in our neighborhood. Now there’s some gossip.

This research was published in The Astrophysical Journal Letters.

This ‘super-Earth’ seems lovely, until you look up

Mike WehnerMon, April 19, 2021, 2:36 PM·3 min read

Earth is great, but what if it were bigger? So-called “super-Earths” are rocky worlds like our own but are several times bigger, and could offer us a new home if we ever were to leave our solar system. Some of the super-Earths that scientists have discovered are too far away from their star to be warm enough for liquid water, so those are a no-go. Some are within or near the habitable zone, which is great news for us, but the vast majority of those are too distant to consider visiting right now. A newly-discovered super-Earth around the star GJ-740 is special because it’s very close to Earth, relatively speaking — only 36 light-years — but there’s another problem. It’s very, very hot.

The planet is estimated to be around three times as massive as Earth. That’s a sizeable chunk of rock, and it’s orbiting a star that is much cooler than our own Sun. GJ-740 is a red dwarf, meaning that its peak temperature is thousands of degrees cooler than our own Sun. Unfortunately, the planet is incredibly close to its star, canceling most of the benefits of orbiting a cooler star and ensuring that the super-Earth’s surface is still very, very warm.

Earth takes a full 365 days to complete an orbit of our Sun. On this newly-discovered super-Earth, a day is much shorter. In fact, the planet completes a full “year” in a mere 2.4 Earth days. That indicates that the planet is incredibly close to its star and, as a result, is absorbing a huge amount of the star’s radiation in the form of heat and various wavelengths of light. The scientists don’t offer a guess as to how hot the planet’s surface is, but it would be absolutely unlivable for any life forms originating on Earth.- ADVERTISEMENT -

“This is the planet with the second shortest orbital period around this type of star. The mass and the period suggest a rocky planet, with a radius of around 1.4 Earth radii, which could be confirmed in future observations with the TESS satellite”, Borja Toledo Padrón, the first author of the article, said in a statement. “The search for new exoplanets around cool stars is driven by the smaller difference between the planet’s mass and the star’s mass compared with stars in warmer spectral classes (which facilitates the detection of the planets’ signals), as well as the large number of this type of stars in our Galaxy”

Story continues

Earth’s oxygen will be gone in 1 billion years

Posted by Kelly Kizer Whitt in EARTH | March 7, 2021

A billion years from now, as the sun heats up, the warmer atmosphere will break down carbon dioxide, killing off plant life, which in turn will shut off Earth’s source of oxygen.Sharing is caring!

Partial view of Earth from orbit with clouds and fuzzy atmosphere visible aganist black space.

The oxygen currently in Earth’s atmosphere will be gone in a billion years, say scientists. This image of Earth’s atmosphere was taken from the International Space Station on February 26, 2021. Image via NASA.

Take a deep breath. The air expanding your chest is mostly nitrogen and oxygen, the chief components of our atmosphere. Oxygen exists in our atmosphere thanks to the exhalation of plants, through the process of photosynthesis. A study released in March 2021 shows that – a billion years from now, as the sun heats up – plants will die off, taking with them the oxygen in our atmosphere that humans and animals need to breathe.

Kazumi Ozaki of the University of Tokyo and Chris Reinhard of Georgia Tech modeled Earth’s climatic, biological and geological systems to fine-tune scientists’ understanding of future atmospheric conditions on Earth. They undertook the research as part of a NASA program called NExSS to explore and assess the habitability of exoplanets. Their study was published March 1, 2021, in the peer-reviewed journal Nature Geoscience.

Earth’s present atmosphere is made up of 78% nitrogen, 21% oxygen, 0.9% argon, and 0.1% other gases, including carbon dioxide, methane, water vapor and neon. Earth hasn’t always had such a high percentage of oxygen in its atmosphere. For Earth’s first 2 billion years, no oxygen existed in the atmosphere. Low levels of oxygen first appeared when cyanobacteria, also called blue-green algae, began releasing oxygen as a byproduct of photosynthesis. Then, about 2.4 billion years ago, Earth underwent the Great Oxidation Event. At this point, whether through a slackening in the outgassing of volcanoes or an evolutionary innovation that made cyanobacteria more successful, oxygen began to accumulate in larger amounts in the atmosphere, killing off some bacteria but allowing more complex life (us!) to evolve.

This oxygen utopia in which we currently live – where plants produce oxygen for humans and animals to breathe – is only a temporary condition on Earth. As Ozaki said:

We find that the Earth’s oxygenated atmosphere will not be a permanent feature.

Man with black hair and thin mustache wearing blue zip-up jacket.

Kazumi Ozaki of the University of Tokyo, lead author on the paper investigating the future of oxygen on Earth. Image via NASA.

As the solar system continues its life cycle, the aging sun will begin to heat up. The increased solar output will further warm the atmosphere, and the carbon dioxide will react to the increase in temperature by breaking down. Carbon dioxide levels will lower until photosynthesizing organisms – which rely on taking in carbon dioxide to live, just as we rely on oxygen to live – can no longer survive, removing the source of oxygen from Earth. (Read about how scientists believe that phytoplankton contribute between 50 to 85% of the oxygen in Earth’s atmosphere.) So when plants die from the lack of carbon dioxide, it’s not just a loss in the food chain but, crucially, a loss in the air they produce and the air we breathe.Skip Ad

While the end of oxygen is still a billion years away, when the depletion begins to take hold, it will occur rather rapidly, in about 10,000 years. Reinhard explained the severity of the change:

The drop in oxygen is very, very extreme; we’re talking around a million times less oxygen than there is today.

Man facing camera standing under a tree.

Chris Reinhard of Georgia Tech, one of the lead authors who researched the future amount of oxygen in Earth’s atmosphere. Image via NExSS.

The future deoxygenation event will coincide with a rise in methane, until methane levels are about 10,000 times more than exist in the atmosphere today. These shifts will occur too fast for adaptation in the biosphere. The ozone layer, made of oxygen, will vanish, and ultraviolet light and heat will aid in extinguishing both terrestrial and aquatic life. All but microbes will face extermination. Reinhard said:

A world where many of the anaerobic and primitive bacteria are currently hiding in the shadows will, again, take over.

Just as in the beginning, when life on Earth was in a microbial form before flourishing into the variety we see today, so too will the future look much like the past, as if the clock is running backward, and complex life forms will go extinct except for tiny colonies of cells.Dry ground and dead trees with wind-blown sand.

All plant and animal life on Earth needs oxygen to survive. A billion years from now, Earth’s oxygen will become depleted in a span of about 10,000 years, bringing about worldwide extinction for all except microbes. Image via Dikaseva/ Unsplash.

Studying the past and future of Earth is a gateway to understanding the conditions favorable to life on other planets. The presence of oxygen is an important factor in determining if life might exist on a planet. As we see with Earth, however, a planet that doesn’t have an oxygen signature may be capable of supporting life in the future or in the past.

Thus, while finding a planet with oxygen would be an exciting step toward finding life, not finding oxygen shouldn’t rule out the possibility that a planet ever had life.

Bottom line: A billion years from now, scientists say, as the sun heats up the warmer atmosphere will break down carbon dioxide, killing off plant life, which in turn will shut off Earth’s source of oxygen.

Source: The future lifespan of Earth’s oxygenated atmosphere