The layers on this stromatolite from Western Australia show evidence of single-celled, photosynthetic life on the shore of a large lake CREDIT: UNIVERSITY OF WASHINGTON
Chiara Palazzo, sydney
10 MAY 2016 • 4:37AM
Air bubbles trapped in 2.7 billion-year-old Australian rock suggest the Earth's atmosphere weighed less than half of today and was much thinner than previously thought.
Researchers analysed the size of air bubbles that formed at the top and bottom of lava flows along the Beasley River in Western Australia's Pilbara region almost three billion years ago and used the data to calculate the atmospheric pressure at the time. The results suggest that the air at the time exerted at most half the pressure of today's atmosphere.
The findings, published on Monday in Nature Geoscience, reverse the commonly accepted idea that the early Earth had a thicker atmosphere to compensate for sunlight being about one fifth weaker than now.
“For the longest time, people have been thinking the atmospheric pressure might have been higher back then, because the sun was fainter,” said lead author Sanjoy Som, who did the work as part of his University of Washington doctorate in Earth and space sciences. “Our result is the opposite of what we were expecting.”
According to the researchers their finding also has implications for which gases were in that atmosphere, and how biology and climate worked on the early planet.
"The result implies that the thin atmosphere was rich in auxiliary greenhouse gases and that atmospheric pressure fluctuated over geologic time to a previously unrecognised extent," the scientists said.
Earth 2.7 billion years ago was home only to single-celled microbes, sunlight was about one-fifth weaker, and the atmosphere contained no oxygen.
The new finding however points to conditions being even more "otherworldly" than previously imagined. A lighter atmosphere could affect wind strength and other climate patterns, and would even alter the boiling point of liquids.
One of the lava flows analyzed in the study CREDIT: UNIVERSITY OF WASHINGTON
“We’re still coming to grips with the magnitude of this,” co-author Roger Buick said. “It’s going to take us a while to digest all the possible consequences.”
Previous discoveries proved that liquid water existed on Earth at the time, in order for that to be possible the early atmosphere must have contained more heat-trapping greenhouse gases like carbon dioxide or methane and less nitrogen.
The result also reinforces Prof Buick’s 2015 finding that microbes were pulling nitrogen out of Earth’s atmosphere some three billion years ago.
“The levels of nitrogen gas have varied through Earth’s history, at least in Earth’s early history, in ways that people just haven’t even thought of before,” said co-author David Catling, a University of Washington professor of Earth and space sciences. “People will need to rewrite the textbooks.”
The researchers will next look for other suitable rocks to confirm the findings and learn how atmospheric pressure might have varied through time.
While clues to the early Earth are scarce, scientists are looking outwards and studying planets outside our solar system in order to understand possible conditions and life on other planets where atmospheres might be thin and oxygen-free, like that of the early Earth.
Scientists Say They Can Recreate Living Dinosaurs Within the Next 5 Years
Brontosaurus
Don’t we already know how this movie’s going to end?
In a potentially terrifying case of life imitating art, the renowned paleontologist who served as the inspiration for Jurassic Park protagonist Dr. Alan Grant is spearheading genetic research that could engineer dinosaurs back into existence within the next five to 10 years, he says.
While Dr. Jack Horner, who has consulted on all four Jurassic films, initially believed the key to recreating the prehistoric creatures lied in working with ancient DNA strands, further study about DNA degradation over time has since ruled out that possibility.
Instead, a group of scientists at Harvard and Yale have turned their eye to -- wait for it -- the modern-day chicken. “Of course, birds are dinosaurs," Horner told People magazine. "So we just need to fix them so they look a little more like a dinosaur."
In an attempt to reverse evolution, the team has already made significant strides in mutating chickens back to the very creatures from which they descended. If that wasn’t enough genetic splicing and dicing, Harvard scientists attempted a similar feat recently by inserting the genes of a woolly mammoth into elephants in order to recreate the extinct beasts. Whoa baby.
If the four major differences between dinosaurs and birds are their tails, arms, hands and mouths, Horner and team have already flipped certain genetic switches in chicken embryos to reverse-engineer a bird’s beak into a dinosaur-like snout.
“Actually, the wings and hands are not as difficult,” Horner said, adding that a ‘Chickensoraus’ -- as he calls the creation -- is well on its way to becoming reality. “The tail is the biggest project. But on the other hand, we have been able to do some things recently that have given us hope that it won't take too long."
Check out Horner discussing the endeavor, among other topics, in the video below:
Jack Horner: "Jurassic World" | Talks at Google
https://www.youtube.com/watch?v=A_qrN7Wa55w
It seems the moon is not Earth's only cosmic companion.
The newly discovered asteroid 2016 HO3 orbits the sun in such a way that the space rock never strays too far from Earth, making it a "quasi-satellite" of our planet, scientists say.
"One other asteroid — 2003 YN107 — followed a similar orbital pattern for a while over 10 years ago, but it has since departed our vicinity," Paul Chodas, manager of NASA's Center for Near-Earth Object Studies at the Jet Propulsion Laboratory in Pasadena, California, said in a statement Wednesday (June 15).
"This new asteroid is much more locked onto us," Chodas added. "Our calculations indicate 2016 HO3 has been a stable quasi-satellite of Earth for almost a century, and it will continue to follow this pattern as Earth's companion for centuries to come."
Indeed, 2016 HO3 is the best example of an Earth quasi-satellite ever found, scientists said.
The asteroid was discovered on April 27 by scientists using the Pan-STARRS 1 survey telescope in Hawaii. 2016 HO3's exact size is unknown, but researchers think it's between 130 feet and 330 feet wide (40 to 100 meters).
The newfound asteroid 2016 HO3 has an orbit around the sun that keeps it as a constant companion of Earth.
Credit: NASA/JPL-Caltech
As the space rock circles the sun, it loops around Earth as well, zooming ahead of the planet half of the time and trailing behind the other half, NASA officials said. 2016 HO3's orbit is tilted slightly relative to that of Earth, so the asteroid also bobs up and down through our planet's orbital plane.
The path of 2016 HO3 tends to twist and drift over time, but Earth's gravitational pull keeps the asteroid contained: It never comes closer than 9 million miles (14.5 million kilometers) to our planet, and it never gets more than 24 million miles (38.6 million km) away, researchers said.
"In effect, this small asteroid is caught in a little dance with Earth," Chodas said.
This dance is not dangerous: 2016 HO3 poses no threat to the planet, NASA officials said.
Follow Mike Wall on Twitter @michaeldwall and Google+. Follow us @Spacedotcom, Facebook or Google+. Originally published on Space.com.
Electro wrote:The following about gravity goes along with Wal's theory:
http://franklinhu.com/NPA20GravityElectric.pdf
I'm with Jeffrey Wolynski and his General Theory of Stellar Metamorphosis: http://vixra.org/pdf/1303.0157vC.pdf Stars evolve into planets in their cores (Marklund convection - Phase transitions). Stars (plasmoids) are formed from pinches between powerful electric currents, just like in the EU theory. However, in GTSM, stars do not remain externally powered. They are double-layer dissipative systems. Therefore, planets (old stars) cannot be hollow. Jupiter, and hopefully Juno will confirm this soon, has a core. And the gas is recombined plasma. The star is still very hot. That's why its radiation is so high (20 million rads).
Marklund Convection:
Phase transitions within stars:
freemanjack wrote:I beg to differ, think of a spherical system with mass as its attractive component, regardless of the nature of that attractive force, if it is derived from mass it will be acting outward in all directions in the centre of a spherical object, the centre of any mass defined gravitational object has zero gravity at its centre, it is inconceivable that any planet or star could form as a solid sphere without a hollow centre under any model.
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