6th mass extinction event could happen by 2100 – study

Over the past 540 million years Earth has suffered five mass extinction events, the worst of which wiped out more than 9 per cent of marine life on the planet. A new study has suggested that the next such catastrophe might not be too far away.

Massachusetts Institute of Technology (MIT) geophysicist and mathematician, Daniel Rothman has been busy studying previous mass extinctions. He reckons the next one might be a mere 83 years away.

The previous five catastrophic events each unfolded over millions of years and involved the natural cycle of carbon through the oceans and atmosphere being disturbed, resulting, in some cases, the death of almost all life on Earth.

The award-winning mathematician identified two “thresholds of catastrophe” that, if exceeded, would upset the natural order of the cycle, leading to an unstable environment and eventually a mass extinction.

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The first relates to changes in the carbon cycle over a period of thousands or millions of years. A mass extinction will occur if the rate of change in the cycle occurs faster than global ecosystems can adapt.

The second pertains to the size or magnitude of the carbon flux over a shorter period, as has been the case over the last century.

Therein lies a problem, however, as Rothman says“How can you really compare these great events in the geologic past, which occur over such vast timescales, to what's going on today, which is centuries at the longest?”

“So I sat down one summer day and tried to think about how one might go about this systematically.”

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Following this, he devised a mathematical formula to determine the total mass of carbon added to the oceans during each event, after which “it became evident that there was a characteristic rate of change that the system basically didn't like to go past.”

Rothman estimates this to be 310 gigatons. He thinks that given the rise of carbon dioxide over the last century, a sixth mass extinction could be on the way as estimates suggest that humans will add roughly 310 gigatons to the cycle by 2100.

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“This is not saying that disaster occurs the next day,” Rothman said. “It’s saying that, if left unchecked, the carbon cycle would move into a realm which would be no longer stable, and would behave in a way that would be difficult to predict. In the geologic past, this type of behavior is associated with mass extinction.”

Rothman's paper was published Wednesday in the journal Science Advances.

Stephen Hawking says humanity must leave Earth within 100 years or face extinction

Physicist and doom-monger fears the next century could spell curtains for our species unless we work out a way of living on another world.

PROFESSOR Stephen Hawking has said humanity has to find a way of leaving Earth or face the extinction of our species.

In the documentary, The Search for a New Earth, he said humans will soon find a way of visiting nearby star systems like Proxima b.

The British genius fears humanity will destroy itself through pollution and climate change, meaning we may one day need to find another place to live.

“I have no doubt we will eventually find ways of crossing the immense distances of space in just a few years," he said, according to The Daily Star.

“One of our greatest strengths is embracing new ideas and evolving them into cutting-edge technologies.

“Our ingenuity will get us to Proxima b and in the next 100 years we will embark on our greatest ever adventure.”

He added: “We must have preparations in place within 100 years. Colonising Proxima b will be a challenge our species like nothing before.”

However, the physicist has previously said that alien species living way out in space pose a huge threat to our species.

“One day, we might receive a signal [from aliens] but we should be wary of answering back,” he said in the documentary Stephen Hawking’s Favourite Places.

“Meeting an advanced civilisation could be like Native Americans encountering Columbus. That didn’t turn out so well.”


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He claimed alien life could be "rapacious marauders roaming the cosmos in search of resources to plunder, and planets to conquer and colonise”.

His fears have not changed since he first spoke out about it on the Discovery Channel in 2010.

He said as he grew older he became more convinced humans were not alone.

“After a lifetime of wondering, I am helping to lead a new global effort to find out,” he said.

Professor Hawking has also warned Earth could become as hot as Venus as a result of climate change.

He told the BBC climate change could turn the planet into a hothouse, and Trump’s decision to pull out of the Paris Climate agreement to reduce CO2 levels could accelerate the threat.

“We are close to the tipping point, where global warming becomes irreversible,” he said.

“Trump’s action could push the Earth over the brink, to become like Venus, with a temperature of 250C, and raining sulphuric acid.”

Hawking also said humans may have to consider living on a different planet elsewhere if climate change ravages our own world.

 

Moon has a water-rich interior

A new study of satellite data finds that numerous volcanic deposits distributed across the surface of the Moon contain unusually high amounts of trapped water compared with surrounding terrains. The finding of water in these ancient deposits, which are believed to consist of glass beads formed by the explosive eruption of magma coming from the deep lunar interior, bolsters the idea that the lunar mantle is surprisingly water-rich.

Scientists had assumed for years that the interior of the Moon had been largely depleted of water and other volatile compounds. That began to change in 2008, when a research team including Brown University geologist Alberto Saal detected trace amounts of water in some of the volcanic glass beads brought back to Earth from the Apollo 15 and 17 missions to the Moon. In 2011, further study of tiny crystalline formations within those beads revealed that they actually contain similar amounts of water as some basalts on Earth. That suggests that the Moon's mantle -- parts of it, at least -- contain as much water as Earth's.

"The key question is whether those Apollo samples represent the bulk conditions of the lunar interior or instead represent unusual or perhaps anomalous water-rich regions within an otherwise 'dry' mantle," said Ralph Milliken, lead author of the new research and an associate professor in Brown's Department of Earth, Environmental and Planetary Sciences. "By looking at the orbital data, we can examine the large pyroclastic deposits on the Moon that were never sampled by the Apollo or Luna missions. The fact that nearly all of them exhibit signatures of water suggests that the Apollo samples are not anomalous, so it may be that the bulk interior of the Moon is wet."

The research, which Milliken co-authored with Shuai Li, a postdoctoral researcher at the University of Hawaii and a recent Brown Ph.D. graduate, is published in Nature Geoscience.

Detecting the water content of lunar volcanic deposits using orbital instruments is no easy task. Scientists use orbital spectrometers to measure the light that bounces off a planetary surface. By looking at which wavelengths of light are absorbed or reflected by the surface, scientists can get an idea of which minerals and other compounds are present.

The problem is that the lunar surface heats up over the course of a day, especially at the latitudes where these pyroclastic deposits are located. That means that in addition to the light reflected from the surface, the spectrometer also ends up measuring heat.

"That thermally emitted radiation happens at the same wavelengths that we need to use to look for water," Milliken said. "So in order to say with any confidence that water is present, we first need to account for and remove the thermally emitted component."

To do that, Li and Milliken used laboratory-based measurements of samples returned from the Apollo missions, combined with a detailed temperature profile of the areas of interest on the Moon's surface. Using the new thermal correction, the researchers looked at data from the Moon Mineralogy Mapper, an imaging spectrometer that flew aboard India's Chandrayaan-1 lunar orbiter.

The researchers found evidence of water in nearly all of the large pyroclastic deposits that had been previously mapped across the Moon's surface, including deposits near the Apollo 15 and 17 landing sites where the water-bearing glass bead samples were collected.

"The distribution of these water-rich deposits is the key thing," Milliken said. "They're spread across the surface, which tells us that the water found in the Apollo samples isn't a one-off. Lunar pyroclastics seem to be universally water-rich, which suggests the same may be true of the mantle."

The idea that the interior of the Moon is water-rich raises interesting questions about the Moon's formation. Scientists think the Moon formed from debris left behind after an object about the size of Mars slammed into the Earth very early in solar system history. One of the reasons scientists had assumed the Moon's interior should be dry is that it seems unlikely that any of the hydrogen needed to form water could have survived the heat of that impact.

"The growing evidence for water inside the Moon suggest that water did somehow survive, or that it was brought in shortly after the impact by asteroids or comets before the Moon had completely solidified," Li said. "The exact origin of water in the lunar interior is still a big question."

In addition to shedding light on the water story in the early solar system, the research could also have implications for future lunar exploration. The volcanic beads don't contain a lot of water -- about .05 percent by weight, the researchers say -- but the deposits are large, and the water could potentially be extracted.

"Other studies have suggested the presence of water ice in shadowed regions at the lunar poles, but the pyroclastic deposits are at locations that may be easier to access," Li said. "Anything that helps save future lunar explorers from having to bring lots of water from home is a big step forward, and our results suggest a new alternative."

The research was funded by the NASA Lunar Advanced Science and Exploration Research Program (NNX12AO63G).


Story Source:

Materials provided by Brown University. Note: Content may be edited for style and length.

It's Raining in Antarctica While Trump Slashes Climate Science Funding

This Memorial Day I awoke in a tent high on Klahhane Ridge in Washington state's Olympic National Park. With the Strait of Juan de Fuca just to the north, and a sweeping view of Mount Olympus and the rest of the park to the south, the sunset the night before went on for hours.

After the sun set, slivers of red arched across the sky in streaks on the underbellies of a few wispy clouds. That night, the stars were so bright they ran all the way down to the horizons. 

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The morning sun found me crawling out of my sleeping bag early. I sat outside eating oatmeal while marveling at the majesty of the park before me. All of the high mountains, including Mount Olympus, were covered in late-spring snow, which covered everything down to 3,000 feet. The grandeur of the wild high country was augmented by the white backdrop.

Climate Disruption DispatchesThe sound of rivers and waterfalls was ever-present in the background, and aside from the one road into the park in this area, the land was unscarred. Yet all around the park, logging has left a patchwork of the forest. And now, emboldened by this particularly destructive administration, the loggers want all of these parks. And in time, I fear they will get them. Because they want everything. They are the Earth eaters. 

That day I wondered, will we have a Memorial Day for all the lost, wild places? Will we have a Memorial Day for all the glaciers that used to be here?

Meanwhile, abrupt anthropogenic climate disruption (ACD) continues apace.

As President Donald Trump announced the US withdrawal from the Paris climate agreement, NOAA [National Oceanic and Atmospheric Administration] released data showing 2016 saw the biggest annual jump in atmospheric CO2 levels on record, coming in at nearly double the average pace.

NASA announced that April was the second hottest April in the history of record-keeping, and that agency, along with NOAA, released data showing that 2016 was the warmest year on record globally, making 2016 the third year in a row to set a new record for global average surface temperatures.

And the records continue to be broken. NASA data showed May to be the second hottest on record, barely trailing 2016 by one-tenth of a degree, and this was the second-warmest spring on record, again only behind 2016. The first five months of this year make it likely that this will be the second hottest year on record, again only behind last year.

Meanwhile, parts of Antarctica are literally beginning to turn green, as scientists there are finding a four- to five-fold increase in the amount of moss growth on the ice continent's northern peninsula.

Even more stunning news comes from Antarctica in a study published in the June 15 issue of the journal Nature Communications which revealed that over an area of West Antarctica, scientists were stunned to find rainfall and a melt area larger than the size of Texas in 2016.

Yes, it is now raining in Antarctica.

The New York Times published a fantastic interactive piece on the ice continent that is well worth a look, while warm temperatures last fall caused water to breach the entrance of the Arctic's "Doomsday" seed vault, one of humans' last hopes of preserving seeds to survive a global catastrophe.

Meanwhile, Arctic sea ice is disappearing off Alaskan coasts more than a month earlier than normal, and due to congressional budget cuts, the 38-year continuous US Arctic satellite monitoring program is about to end, leaving researchers in the dark about ongoing sea ice losses.

And this May, atmospheric CO2 content set an all-time monthly high when it reached 409.65ppm, according to NOAA data.

Earth

Anthropogenic climate disruption has created stunning major developments in the lives of the Earth's plants and animals over recent weeks.

A recently published paper in the journal Scientific Reports shows how ACD is disrupting the timing of dozens of songbird species. Timing is critical for migratory birds, because if they arrive too late they only get the tail end of the spring's insect supply and have trouble finding nesting spots and mates. On the other hand, if they arrive too early, they will arrive in temperatures colder than they are prepared to deal with. Yet, ACD is causing spring to arrive earlier in eastern US states and later in the west, disrupting the timing of dozens of bird species.

This is threatening the survival of many species that are currently popular in many people's backyards. "The long-term concern is that this growing mismatch can lead to population declines," Stephen Mayor, the study's primary researcher said in an interview.

An interesting thing is happening to trees in the US -- they are moving westward, and nobody seems to know why, aside from the influence of ACD, which scientists say accounts for 20 percent of the reason. One main hypothesis is that the trees are following moisture as it moves westward: The east has been getting less rain, and the great plains are getting more.

Meanwhile, a vast dieback of trees caused by a tiny beetle from southeast Asia that is on track to kill 26.8 million trees across Southern California over the next few years is expected to bring about a human death toll that could reach into the thousands. A recent report cited differences in illnesses and deaths in human populations that live near greenery versus those who do not, and is predicting these ramifications from the widespread tree dieback.

In other parts of the world, ACD-driven extreme weather events and wild temperature swings are predicted to slash major staple crop production (corn, wheat, rice, soybeans) by nearly one-quarter over the upcoming 30 years, according to another report.

In another astounding turn of events, a recently released study showed that in Greenland, so much water and ice rushed through a melting glacier that it literally warmed the Earth's crust. A mass of melting ice the size of 18,000 Empire State Buildings traveled over 15 miles through the Rink Glacier in 2012, a record melting year for the ice sheet.

Eric Rignot, a leading expert on the melting of the Greenland Ice Sheet from the University of California, Irvine, recently told Scientific American that in the Arctic, the Greenland Ice Sheet poses the single greatest risk for ocean levels due to the obvious fact that land ice that is melting, like Greenland, is the single biggest cause of rising seas, and that "most of the Arctic's land ice is locked up in Greenland." If the entire Greenland Ice Sheet melted, it would raise sea levels an average of seven meters.

And the consequences of a melting Greenland Ice sheet are far from limited to global sea level rise. A study published in the Proceedings of the National Academy of Sciences suggests that if the melting is large enough, it could literally change global weather patterns that could result in devastating crops in Africa. In sum, the massive influx of freshwater from the melting ice sheet could disrupt a major ocean current system, which would then dry out the Sahel of Africa. The consequences of this would be devastating agricultural losses as that area's climate shifts, and upwards of tens of millions of people could be forced to migrate out of the area in the worst-case scenario.

And that's not the only place major changes in melting ice are having an impact on the planet.

In Savoonga, Alaska, a village island 164 miles west of Nome in the Bering Sea, the sea ice is arriving later and going out earlier than ever before, and with it, the walruses the natives in the village depend on. "This year it's worse. Unusual. The ice moved out in April," Larry Kava, 76, a tribal and cultural leader in Savoonga, told the Alaska Dispatch News.

Water

Not surprisingly, a recently published study in which researchers looked very closely at cities lining US coasts found that they will flood more often and more severely as ACD progresses. The study warns that cities should brace for much more flooding, from what they refer to as "nuisance" floods that cover streets at high tides, to deluges that kill people and take out vast swaths of infrastructure.

As if to underscore that point, another recent study has found that Earth's oceans are now rising three times as rapidly as they had been throughout much of the last century, showing that sea level rise acceleration is now very much under way.

At the same time, other land-based glaciers and ice fields continue to wither at ever-increasing paces. Recently released data from the USGS and Portland State University showed that ACD has dramatically reduced the size of 39 glaciers across Montana since just 1966. Some of them have been reduced by 85 percent, and on average Montana's glaciers have been reduced by 39 percent, and only 26 of the remaining glaciers are larger than 25 acres, the minimum size threshold used to decide if bodies of ice are large enough to be considered glaciers.

Seeing the writing on the wall, a team of international scientists in Bolivia called the "Ice Memory" expedition is working feverishly to transport samples of ice from a melting glacier there to Antarctica, in order to preserve and study the 18,000 years of climate history embedded within the ice before the glacier disappears completely.

Meanwhile, as oceans continue to warm, global coral bleaching continues apace.

The Australian government's primary aim of protecting the Great Barrier Reef is now no longer achievable due to the dramatic impacts of ACD, according to experts advising that country's governmental advisory committee for the plan. The reef is now likely to become listed as a World Heritage Site in Danger.

The coral bleaching event that struck the Great Barrier Reef this year was recently revealed to have had an escalating impact from north to south, killing 70 percent of all shallow-water corals north of the coastal town of Port Douglas.

Another report has gone so far as to claim that the damage already done to the Great Barrier Reef is so great that the reef is beyond repair and can no longer be saved, at least according to some scientists. This is, they said, because of the "extraordinary rapidity" of ACD, and because roughly 95 percent of the reef has been bleached since 2016.

In the US, NOAA scientists recently warned that US coral reefs are on a course to disappear within just a few decades, and the Chagos Archipelago, a small group of roughly 60 islands in the Indian Ocean, was recently found to also be devastated by ACD impacts. After back-to-back bleaching events in 2015 and 2016, scientists there found approximately 90 percent of the coral in shallow waters to already be dead.

Ocean waters in the tropics are becoming so warm that a leading fisheries expert recently warned that fish are literally abandoning tropical waters.

Meanwhile flooding is progressing apace as extreme rain events continue to happen more frequently. In late May, Sri Lanka was seeing flooding from its most torrential rains since 2003. At least half a million people were impacted, with a death toll of at least 169 according to the Disaster Management Centre.

Another recent report revealed that three-fourths of California's native species and subspecies of salmonids (fish in the salmon family) may be extinct within 100 years, primarily due to ACD impacts and severe degradation of wild river habitats, according to biologists at the University of California, Davis, and the watershed advocacy group California Trout. In their study, "State of the Salmonids II: Fish in Hot Water," the authors warned that climate change impacts and the severe degradation of habitat of wild rivers that continues to this day could extinguish almost half of California's 32 types of native salmon and trout within 50 years.

Fire

There have been several major fires over the last month, many of which affected the US.

Southern California saw a 950-acre wildfire near Big Bear Lake. And in Utah, hundreds of people had to flee a ski town due to a rapidly spreading fire. In Arizona, more than eight structures burned as more than 100 firefighters worked to contain the wildfire amid extreme heat, hot winds and bone-dry vegetation.

In New Mexico, a volunteer fire fighter died from burns, while in Portugal raging wildfires killed at least 62, many of whom died in their cars while trying to flee to safety.

In the US, at the time of this writing, 27,943 wildfires have burned more than 2.5 million acres thus far for 2017.

Air

Methane, a greenhouse gas that is at least 20 times more potent than CO2, is already being released across much of the Arctic at far higher levels than ever recorded.

Hundreds of huge craters (some of which are half a mile wide) were recently discovered in the Arctic Ocean sea floor -- craters that formed after ice sheets melted, allowing trapped methane to blow out. One of the authors of a study on these craters described the event as being like "champagne bottles being opened" -- a phenomenon that could well happen again.

Meanwhile, examples of rapidly escalating global temperatures abound.

A recent study shows that India is now 250 percent more likely to experience deadly heat waves than it was just 50 years ago, and all it took to produce this dramatic change was increasing the average temperature there by just 0.5 Celsius.

In June, a record-breaking heat wave in the Southwestern US affected 40 million people. The heat wave was so intense it cracked pavement, threatened power grids, caused escalated risk of serious injuries and grounded flights. Temperatures reached 127 degrees Fahrenheit in Death Valley, California, the hottest June 20th ever recorded there, and Phoenix saw 119 Fahrenheit. Las Vegas tied its all-time heat record of 117 Fahrenheit (the previous time it saw that kind of heat was just four years ago), and temperature records were set across other parts of Arizona, Nevada and California.

Forty-three flights were grounded in Phoenix when aircraft could not generate enough lift for a safe take-off in thin, low-density super-heated air. By the time of this writing, more than 50 flights had been grounded from the heat.

At one point in Arizona in June, it had never been that hot for that long, in the history of record keeping. For example, in Tucson, a record-setting seven consecutive days of intense heat saw highs above 110 Fahrenheit -- the longest streak of such heat in the city's history.

Also at the time of this writing, at least four people had died from the heat in the Southwest, with that figure expected to rise as the heat wave persisted.

recently released study shows that one-third of the population of the planet now faces deadly heat waves due to ACD, and the number of people in danger will grow to nearly 50 percent by 2100 even if emissions are dramatically reduced before then.

And another recent report warns that ACD is pushing tropical diseases toward the Arctic Circle as the atmosphere continues to warm. This means that rare pathogens from the hotter parts of the planet are already creeping toward the north, and some of these diseases are already appearing near the Arctic.

Denial and Reality

Never a dull moment on the ACD denial front with the Trump administration.

US Energy Secretary (and scientist extraordinaire) Rick Perry said he does not believe CO2 emissions are the primary driver of Earth's warming, hence denying a core finding of ACD science. Instead of CO2 emissions driving warming, Perry claims the driver to be "the ocean waters and this environment we live in."

Trump named a BP oil disaster lawyer, Jeffrey Bossert Clark, who has also repeatedly challenged the science behind US climate policy, as the country's top Department of Justice environmental attorney. Trump's budget request to Congress will also eliminate or shrink core programs the federal government uses to track heat-trapping gases, while 85 percent of the top science jobs in Trump's government remain without a nominee, and the White House thinks the government has been spending too much money on climate science and the new budget from Trump aims to kill "crazy" climate science.

On the reality front, climate scientists are now uniting with lawyers in order to build networks to respond to attempts by the government to subvert their research and threaten them, and a recent poll shows that eight out of 10 people see ACD as a "catastrophic risk."

More news outlets are running stories asking the question of whether or not it makes sense to bring new children into an increasingly climate-disrupted world with a dystopian future that looks more inevitable by the day, and more than 1,400 cities, states and businesses in the US have vowed to meet the Paris climate commitments in the wake of Trump announcing the US withdrawal from the accords.

French President Emmanuel Macron is actively luring US climate researchers to move to France to do their work by offering four-year research grants, staff and coverage of other expenses, and China is now looking to California Gov. Jerry Brown, not Trump, as a partner to work with in mitigating ACD.

Meanwhile, evidence of ACD becoming more abrupt continues to mount. A recently published study shows that ACD-intensified storms over the US Great Plains may well already be eroding the protective ozone layer of Earth's atmosphere, meaning that for starters, the risk of skin cancer and destruction of plants and crops is more likely.

And the final reality check comes in from another recent study that confirmed the planet is already warming 20 times faster than it did during its fastest natural climate change, which occurred when it came out of the last Ice Age.

Dinosaur asteroid hit 'worst possible place'

Scientists who drilled into the impact crater associated with the demise of the dinosaurs summarise their findings so far in a BBC Two documentary on Monday.

The researchers recovered rocks from under the Gulf of Mexico that were hit by an asteroid 66 million years ago.

The nature of this material records the details of the event.

It is becoming clear that the 15km-wide asteroid could not have hit a worse place on Earth.

https://ichef.bbci.co.uk/news/624/cpsprodpb/CA49/production/_96058715_bm_bm_eotd_02738308.jpgThe drill rig was on station in the Gulf in April and May last year / BARCROFT PRODUCTIONS/BBC

The shallow sea covering the target site meant colossal volumes of sulphur (from the mineral gypsum) were injected into the atmosphere, extending the "global winter" period that followed the immediate firestorm.

Had the asteroid struck a different location, the outcome might have been very different.

"This is where we get to the great irony of the story – because in the end it wasn’t the size of the asteroid, the scale of blast, or even its global reach that made dinosaurs extinct – it was where the impact happened," said Ben Garrod, who presents The Day The Dinosaurs Died with Alice Roberts.

https://ichef-1.bbci.co.uk/news/624/cpsprodpb/5901/production/_96058722_bm_bm_eotd_02738320.jpgThe fractured rocks were subjected to immense pressures / BARCROFT PRODUCTIONS/BBC

"Had the asteroid struck a few moments earlier or later, rather than hitting shallow coastal waters it might have hit deep ocean.

"An impact in the nearby Atlantic or Pacific oceans would have meant much less vaporised rock – including the deadly gypsum. The cloud would have been less dense and sunlight could still have reached the planet’s surface, meaning what happened next might have been avoided.

"In this cold, dark world food ran out of the oceans within a week and shortly after on land. With nothing to eat anywhere on the planet, the mighty dinosaurs stood little chance of survival."

Ben Garrod spent time on the drill rig that was stationed 30km off Mexico's Yucatan Peninsula in April/May last year, to better understand the aims of the project; Alice Roberts visited widely separated fossil beds in the Americas, to get a sense of how life was upended by the impact.

Rock cores from up to 1,300m beneath the Gulf were recovered.

The lowest sections of this material come from a feature within the crater called the peak ring.

This is made from rock that has been heavily fractured and altered by immense pressures.

By analysing its properties, the drill project team - led by Profs Jo Morgan and Sean Gulick - hope to reconstruct how the impact proceeded and the environmental changes it brought about.

Chicxulub Crater - The impact that changed life on Earth

  • A 15km-wide object dug a hole in Earth's crust 100km across and 30km deep
  • This bowl then collapsed, leaving a crater 200km across and a few km deep
  • The crater's centre rebounded and collapsed again, producing an inner ring
  • Today, much of the crater is buried offshore, under 600m of sediments
  • On land, it is covered by limestone, but its rim is traced by an arc of sinkholes
  • They know now the energy that went into making the crater when the asteroid struck - equivalent to 10 billion Hiroshima A-bombs. And they also understand how the depression assumed the structure we observe today.

    The team is also gaining insights into the return of life to the impact site in the years after the event.

    One of the many fascinating sequences in the BBC Two programme sees Alice Roberts visit a quarry in New Jersey, US, where 25,000 fossil fragments have been recovered - evidence of a mass die-off of creatures that may have been among the casualties on the day of the impact itself.

    "All these fossils occur in a layer no more than 10cm thick," palaeontologist Ken Lacovara tells Alice.

    "They died suddenly and were buried quickly. It tells us this is a moment in geological time. That's days, weeks, maybe months. But this is not thousands of years; it's not hundreds of thousands of years. This is essentially an instantaneous event."

    The Day The Dinosaurs Died is on BBC Two at 21:00, after which it will be available on the BBC iPlayer.

Huge ‘potentially hazardous’ asteroid hurtling towards Earth

A huge 1km-wide asteroid is hurtling towards Earth, prompting astronomers to label it “potentially hazardous”. But don’t pack for Mars just yet – the giant space rock, ‘2014 JO25’, is expected to pass by our planet safely.

According to NASA the encounter on April 19 will be the closest the asteroid comes to Earth in 400 years, and no projected future encounters will be as close for at least another 480 years.

However, another fly-by is expected in 2091 and the space rock also makes regular close approaches to Mercury and Venus.

 
An asteroid of this size won't have as close an encounter with Earth for more than 10 years. "The next known flyby by an object with a comparable or larger diameter will occur when 800-meter-diameter asteroid ‘1999 AN10’ approaches within one lunar distance in August 2027," NASA said.

The asteroid was discovered by the Mt. Lemmon Survey in May 2014. Astronomers describe it as a “bright object” and believe it will be among the best targets for radar observations this year.

READ MORE: Risk of catastrophic asteroid impact ‘real’ – White House

‘2014 JO25’ has been designated as a potentially hazardous asteroid (PHA) by the Minor Planet Center. PHA’s are asteroids larger than 100 meters that can come closer to Earth than 7,495,839km (about 4,658,000 miles), which is equal to 19.5 ‘Lunar distances’.

Asteroid Hazards, Part 1: What Makes an Asteroid a Hazard?

Despite 2014 JO25’s designation as a PHA, projections predict it will pass by Earth at a safe distance of about 1.8 million km (4.57 lunar distances).

@BadAstronomer Pic of a 10-meter rock that passed inside the Moon’s orbit a couple of hours ago. Amazing we can find these things. http://www.virtualtelescope.eu/2017/04/02/near-earth-asteroid-2017-fu102-close-encounter-image-2-apr-2017/ 


 
 
 

Two other big asteroids, ‘2003 BD44’ and ‘1999 CU3’, which are both nearly 2km wide, will also pass by our planet shortly, however they won’t come as close as 2014.

Astrowatch report 1,781 PHAs were detected on Sunday, however – happily – none of them is on a projected collision course with Earth.

Oldest-ever fossils show life existed on Earth at its infancy - study

Ancient fossils discovered in Canada are “direct evidence” that life existed on Earth 4 billion years ago, scientists wrote in a newly-released study, believing the emergence of life could be simple enough to begin on other planets.

Researchers believe the microfossils – discovered in Canada's Nuvvuagittuq Supracrustal Belt, which hosts some of the oldest sedimentary rocks known on Earth – are between 3.77 billion and 4.29 billion years old.

The discovery has led scientists to believe that life was present during the infancy of the planet, which is thought to be around 4.57 billion years old.

If the dating is accurate, it would represent an “almost instantaneous emergence of life” after ocean formation, lead author Matthew Dodd said, as quoted by Reuters.

READ MORE World's oldest fossils unearthed (UCL)

The tiny microfossils were found to be half the width of a human hair and up to half-a-millimeter in length. Their appearance is of blood-red tubes and filaments, formed by ocean-dwelling bacteria that fed on iron.

The dating puts the fossils “within a few hundred million years of the acceleration of the solar system,” University College London Professor Dominic Papineau, who made the discovery, said in a video statement cited by AFP.

Even at the lower end of the range, “the microfossils we discovered are about 300 million years older” than any runners-up, Papineau said.

Locked inside white quartz structures, the microfossils were found in what were once warm-water vents on the ocean floor, most often in deep waters.

The finding has prompted scientists to hypothesize that such vents may have been some of the earliest habitable environments on the planet.

However, one of the researchers acknowledged skepticism about whether such fossils are biological in nature, or merely natural mineral formations.

“One of the big questions when it comes to early life studies is whether or not the organic carbon we find in these rocks is actually biological in origin,” Dodd said, as quoted by AFP.

Dodd and his colleagues used several methods to determine the answer to that question, including laser-imaging to analyze the minerals associated with the organic material.

They concluded that the presence of two minerals in particular – apatite and carbonite – provide strong evidence for life.

Moreover, the scientists noted that the microfossils’ structure closely resembles modern bacteria that dwell near iron-rich hydrothermal vents.

The possibility that the microfossils were formed by temperature and pressure changes as the sediment formed were also examined and excluded.

Perhaps the most intriguing piece of the research is that Dodd believes there’s no reason to rule out similar evidence of early life being found on other planets.

READ MORE: 500mn years old & boasting 30 legs: ‘Worm’ fossil offers insight into ancient species (VIDEO)

“We could expect to find evidence for past life on Mars 4 billion years ago,” Dodd said, stating that Earth and Mars had liquid on their surfaces at the same time.

“If life happened so quickly on Earth, then could we expect it to be a simple process that could start on other planets?” he said.

He admitted, however, that Earth could be “just a special case.”

The discovery represents a significant milestone, as the oldest microfossils previously reported were found in Western Australia and dated to 3.46 billion years old. However, some scientists say they are not biological in origin.

Researchers from various institutions, including the US Geological Survey, took part in the study. The results were published in the journal Nature on Wednesday.

NASA has discovered 7 Earth-like planets orbiting a star just 40 light-years away

This tiny star has 7 planets that potentially could be suitable for life.

The first step in finding life outside our own planet is to find a planet like our own: small, rocky, and at just the right distance from the star that liquid water could exist on its surface.

That’s why an announcement today from NASA is so exciting: The space agency, along with partners around the world, has found seven potentially Earth-like planets orbiting a star 40 light-years away.

“It’s the first time that so many planets of this kind are found around a same star,” Michaël Gillon, the lead author of the Nature paper announcing the discovery, said in a press conference. “The seven planets … could have some liquid water and maybe life on the surface.”

Three of the planets are directly in the star’s habitable zone, meaning water can mostly likely exist on the surface of them. One of them, Gillon said, has a mass “strongly to suggest a water-rich composition.” And it’s possible that the other four could have liquid water, too, depending on the composition of their atmospheres, the astronomers said.

 The planets “e,” “f,” and “g” — marked in green are directly in the “habitable zone” of this star system. NASA

The exoplanets orbit a star in the constellation Aquarius called Trappist-1. And it’s a solar system very different from our own.

For one, Trappist-1 is a tiny, “ultra-cool” dwarf star. It’s cool because it’s small: just about a tenth of the mass of our sun and about one-thousandth as bright. But its low mass allows its planets to orbit it very closely and remain in the habitable zone.

The distance at which the planets orbit Trappist-1 is comparable to the distance of Jupiter to its moons. All the planets are believed to be rocky, and are all believed to be around the size of Earth, give or take 10 to 20 percent.

The star’s dimness is actually what led to the discoveries of these planets. When astronomers search for exoplanets, they typically look for a temporary dimming of a star — an indication that a planet has passed in front of it. This method makes it hard to find small, rocky worlds orbiting big, bright stars. If the planets are too small, they’ll get washed out.

“Maybe the most exciting thing here is that these seven planets are very well suited for detailed atmospheric study,” Gillon said. The James Webb Space Telescope, set to launch in 2018, will have the ability to measure the chemical composition of exoplanet atmospheres. If the atmospheres contain telltale gases like ozone, oxygen, or methane, life could exist there. “We can expect that in a few years, we will know a lot more about these [seven] planets,” Amaury Triaud, another of the paper’s co-authors, said.

If this all sounds a bit familiar, it’s because astronomers announced three potentially habitable planets around Trappist-1 in May. Today’s reveal adds four more to the mix.

Right now, the astronomers are beginning to study the planets’ atmospheres with the telescopes they have. And from these observations, they feel fairly confident that the worlds are rocky. “For detailed characterization, we will need James Webb,” Triaud said.

In the meantime, we just have our imaginations to fill in the gap. This is an artist’s rendition of what the fifth planet in this bizarre solar system might look like. These planets are believed to be tidally locked to the star, each has a permanent day side and a permanent nice side. And because the planets are so close together, they’d appear in the sky like moons.

 This artist's concept allows us to imagine what it would be like to stand on the surface of the exoplanet Trappist-1f. Dream vacation? NASA/JPL-Caltech

The more Earth-like exoplanets astronomers find in the galaxy, the more they update their estimates of how many Earth-like planets could be out there. “For every transiting planet found, there should be a multitude of similar planets (20–100 times more) that, seen from Earth, never pass in front of their host star,” Nature reporter Ignas Snellen explains in a feature article. And the more exoplanets there are, the more likely it is that life exists on at least one of them.

“With this discovery we’ve made a giant, accelerated leap forward in our search for habitable worlds and life on other worlds potentially,” Sara Seager, a leading exoplanet expert at MIT, said during the announcement. This one star system, she said, gives astronomers many chances to look for life, and refine their understanding of exoplanets in small-star systems.

Also promising: Tiny, cool stars like Trappist-1 are some of the most common in the galaxy. Investigating them will likely yield more exoplanet discoveries. Which will help get us closer to finding places like Earth.

As NASA associate administrator Thomas Zurbuchen said, “Finding another Earth-like planet isn't a matter of if but when.“

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