dedicated bY: Kavignar Thanigai.
MELBOURNE: Scientists have solved the mystery of how the first animals appeared on Earth, a pivotal moment for the planet without which humans would not exist.
Researchers led by The Australian National University (ANU) analysed ancient sedimentary rocks from central Australia, finding that the evolution of animals began with the rise of algae 650 million years ago.
“We crushed these rocks to powder and extracted molecules of ancient organisms from them,” said Jochen Brocks, associate professor at ANU.
“These molecules tell us that it really became interesting 650 million years ago. It was a revolution of ecosystems, it was the rise of algae,” said Brocks, who led the research published in the journal Nature.
Brocks said the rise of algae triggered one of the most profound ecological revolutions in Earth’s history, without which humans and other animals would not exist.
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“Before all of this happened, there was a dramatic event 50 million years earlier called Snowball Earth,” he said.
“The Earth was frozen over for 50 million years. Huge glaciers ground entire mountain ranges to powder that released nutrients, and when the snow melted during an extreme global heating event rivers washed torrents of nutrients into the ocean,” Brocks said.
Brocks said the extremely high levels of nutrients in the ocean, and cooling of global temperatures to more hospitable levels, created the perfect conditions for the rapid spread of algae.
It was the transition from oceans being dominated by bacteria to a world inhabited by more complex life, he said.
“These large and nutritious organisms at the base of the food web provided the burst of energy required for the evolution of complex ecosystems, where increasingly large and complex animals, including humans, could thrive on Earth,” Brocks said.
Co-lead researcher Amber Jarrett discovered ancient sedimentary rocks from central Australia that related directly to the period just after the melting of Snowball Earth.
“In these rocks we discovered striking signals of molecular fossils,” said Jarrett, a PhD graduate at ANU Research School of Earth Sciences.
“We immediately knew that we had made a ground-breaking discovery that snowball Earth was directly involved in the evolution of large and complex life,” said Jarrett.
This Incredible Plane Could Fly from the U.S. to England in Only 20 Minutes
THANKS: READERS DIGEST 16.07.2017
Brooke Nelson : Reporter
dedicated by: kavignar Thanigai
Science has finally found a cure for your wanderlust woes. Thanks to the new Antipode airplane, passengers could one day fly from London to New York in just 20 minutes.
Let’s repeat that: Twenty. Minutes. Have we just gotten one step closer to teleportation?
Canadian designer Charles Bombardier thinks so! Although it would use a normal runway, his plane would travel at supersonic speeds after take off, METRO reports. Using what he calls ‘low penetration mode,’ the aircraft would rapidly channel air across a nozzle on its nose, reaching a top speed of 18,264 miles per hour. By the way, that’s 24 times the speed of sound. No big deal.
‘The idea of going from New York to London in, say 20 minutes – that’s what I think really grabbed people,’ Bombardier told BBC. ‘It’s always something that people would like – a transportation system that could take you from one place on the planet to the other side.’
Plus, with its ability to reach a peak height of 40,000 feet, this plane is out of this world (literally!) Here’s the trade-off, though: The aircraft, which is just a concept for now, would only be able to sit 10 people. So if this ever reaches the mainstream market, getting tickets will be pricey—not to mention competitive.
But when push comes to shove, we’ll be holding out hope to one day cross the Atlantic in roughly the same amount of time it takes to commute to work. In the meantime, you can still book a cheap flight to Hawaii; just make sure to follow these air travel tips before your next flight.
Also watch: The man who takes a plane to work (Provided by BBC)
More from MSN Travel
In pics: Very best seat on an airplane for every type of need (Provided by Reader’s Digest)
Colonizing Mars has long captivated the human imagination, and NASA is no exception.
The American space agency has made landing humans on Mars a high priority of its exploration programs and under bipartisan 2010 legislation pledged to develop the capabilities to send humans to the planet by the 2030s.
But there remains a major problem standing between mankind and the red planet: money.
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The head of NASA’s program on human exploration of space, William Gerstenmaier, said on Wednesday that with its current budget the agency simply cannot afford the cost of propelling a manned spacecraft to Mars.
Through this horizon, through the 2030s, I can’t put a date on humans on Mars,” said Gerstenmaier on Wednesday, in response to a question at a propulsion meeting of the American Institute for Aeronautics and Astronautics in Georgia.
Read more: Skintight space suits are the order of the day for astronauts who hope to survive life on Mars
“At the budget levels we’ve described—it’s roughly a 2 percent increase—we don’t have the surface systems available for Mars. That entry, descent and landing is a huge challenge for us for Mars.”
NASA has landed several unmanned exploratory vehicles on Mars in the past. The Curiosity rover, which landed on Marsh in August 2012 and will soon be celebrating its five-year anniversary exploring the planet, cost around $2.5 billion.
Gerstenmaier said that a manned mission to Mars would weigh around twenty times what previous rovers have weighed. “So it’s a twenty-fold increase in capability,” he said, likely meaning a much higher cost.
Lawmakers allocated NASA a budget of $19.5 billion for the 2017 fiscal year, which equates to less than half a percent of the overall federal budget.
The agency has not produced a specific figure of the cost of a manned mission to Mars, and estimates vary depending on sources. In 2012, the head of NASA’s Jet Propulsion Laboratory, Brent Sherwood, estimated that the project could cost up to $100 billion over the course of 30 or 40 years. More recently, Pascal Lee, the director of the Mars Institute—a nonprofit research group funded partially by NASA and based at a NASA research center in Silicon Valley—said in May that a human mission to Mars could cost up to $1 trillion over 25 years.
Private organizations that are working on their own missions to Mars have estimated lower costs. Mars One, a Dutch-Swiss organization aiming to establish a permanent settlement on Mars, aims to bring four people to Mars at a cost of $6 billion. SpaceX founder Elon Musk, who has said he wants to send humans to Mars in the early 2020s, put the cost at $10 billion per person in 2016.
Landing on Mars poses numerous threats to a manned mission. The spacecraft must angle its entry into the Martian atmosphere correctly: If it is too steep, the craft may burn up, and if too shallow the craft may miss the planet altogether. Astronauts must use reverse thrusters and parachutes to slow the spacecraft down so that it is not destroyed upon impact with the surface. The craft must also locate a safe landing surface on the rugged terrain of Mars, parts of which are peppered with gigantic craters.
And while research has shown that liquid water once flowed on Mars, a recent study found that the soil is toxic to bacteria —one of the simplest forms of living organisms—and thus may also pose problems for sustaining human life.
Astronomers using the Kepler space telescope have detected 219 possible new exoplanets in our galaxy, including 10 relatively small, rocky and possibly habitable planets similar to our own, NASA announced Monday.
These are the last additions to the catalog of exoplanets compiled during the first phase of the Kepler mission, when the space telescope scanned some 200,000 stars in the Cygnus constellation in an effort to find worlds beyond our own. The official catalog now contains 4,034 total “candidates” – tiny blips in the data that are thought to signal the presence of a planet around a star. Of these, 49 fit squarely into their star’s “habitable zone,” that Goldilocks region where liquid water can pool on the surface and life may be able to thrive.
The Kepler space telescope was launched into orbit around the sun in 2009. Its charge: Take a census of a small slice of the Milky Way in an effort to understand the “demographics” of our galaxy. How many stars are like our sun? How many of those host planets? How many planets orbit in the habitable zone? Is there anyplace else in this vast universe that living beings might call home?
In its first four years, Kepler surveyed just .025 percent of the sky. And for every potential planet detected, NASA estimates that 100 to 200 lurk beyond the telescope’s reach. Given a little time and some sophisticated models, scientists will use the Kepler catalogue to estimate how many stars in our galaxy could host an “Earth 2.0.”
Based on how many habitable-zone planets have already been identified, Caltech astrophysicist Courtney Dressing thinks that number could be sizable.
“I, for one, am ecstatic,” she said at a news conference Monday.
“The important thing for us is, are we alone?” added Kepler Program Scientist Mario Perez. “Kepler today tells us, indirectly, . . . that we are probably not alone.”
This is the eighth update of the Kepler planet catalogue and the most thorough survey of the space telescope’s data to date. Of the 4,034 candidates, more than half have already been confirmed as exoplanets and not the result of miscalculations or false signals. Kepler research scientist Susan Thompson, the lead author of the catalogue study, said her team is confident about all 10 of the new “Earth-like” planets found in their stars’ habitable zones.
Several of these planets orbit G dwarfs – the same species of star as our own sun. And one, dubbed KOI 7711 (for Kepler Object of Interest), is a possible “Earth twin,” a rocky world just 30 times bigger than our own and roughly the same distance from its star.
It’s too soon to say whether KOI 7711 truly merits the label “Earth-like,” Thompson cautioned. Kepler is incapable of determining whether an exoplanet bears an atmosphere or liquid water. If aliens were observing our solar system using a similar instrument, they might think it contained three rocky, potentially habitable worlds – Venus, Earth and Mars. “But I’d only want to live on one of them,” Thompson said.
A second research group combined the Kepler data with measurements from ground-based telescopes to calculate the approximate sizes and compositions of 2,000 exoplanets. They found that smaller worlds, the kind that Kepler was designed to detect, fall into two distinct groups: rocky planets that could be up to 1.75 times the size of our own, called “super-Earths,” and gaseous “mini-Neptunes,” which lack a solid surface and are 2 to 3 times bigger than Earth. Nearly every star surveyed hosted a planet in one of these two categories. But, curiously, no planets straddled the divide. Each world was either smaller and rocky, or larger and gassy.
Benjamin Fulton, an astronomer at Caltech and the University of Hawaii at Manoa, compared the new categories to species of animal.
“Finding two distinct groups of exoplanets is like discovering mammals and lizards make up distinct branches of a family tree,” he told reporters Monday. And just as discovering distinctions between species helps us understand evolution, this revelation could help astronomers determine how planets take shape.
Fulton and his colleagues believe that the sharp distinction between “super-Earths” and “mini-Neptunes” may be a result of how much hydrogen and helium contributed to their formation. These elements are extremely light and exist as gas at all but the lowest temperatures. Rocky worlds like Earth, with thin atmospheres and nice, firm surfaces, contain relatively little of these elements. Perhaps they started off with less, or perhaps the light elements were burned or blown away.
But if a planet can hold onto just a bit more of these gases, it “puffs up” like a balloon, Fulton said. Hydrogen and helium form vast, thick atmospheres around mini-Neptunes, making these worlds much bigger than their rocky counterparts.
It’s difficult to know for sure, because our own sun doesn’t host a mini-Neptune – unless you count the hypothesized “Planet Nine” that some scientists believe lurks at the outer edge of the solar system. (For the record, Fulton doesn’t – not yet.) But researchers are bent on figuring out what leads a world to become rocky, rather than gassy, because as far as we’re aware life can only take shape on solid ground.
Kepler’s original mission ended in 2013 when one of the wheels that helped to keep the spacecraft pointed toward the Cygnus constellation failed, so it could no longer scan the same small slice of sky. But by using pressure from light particles from the sun to stay oriented, the telescope has been refashioned for a second exoplanet search project called K2. NASA estimates the telescope has enough fuel to remain active into 2018.
By then, the space agency hopes to be ready to launch the Transiting Exoplanet Survey Satellite, which will search for small planets around the brightest stars in the sky, and the James Webb Space Telescope, which is designed to detect atmospheres on other planets. The results from Kepler, that new satellite and the Webb will inform the next generation of telescopes – ones that can actually take pictures of planets in motion around distant stars.
“It feels a bit like the end of an era,” Thompson said, “but actually I see it as a new beginning. It’s amazing the things that Kepler has found. It has shown us these terrestrial worlds, and we still have all this work to do to really understand how common Earths are in the galaxy.”