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Future Earthlings Won’t See Total Solar Eclipses…Here’s Why:

How was your eclipse?

 

Experiencing this fluke is even more rare than we can imagine…

 

From “Heard on Morning Edition,”

 

Why Future Earthlings Won’t See Total Solar Eclipses

by Nell Greenfieldboyce

 

“Anyone who gets to see the total solar eclipse on August 21 will be lucky — and humanity is lucky to live on a planet that even has this kind of celestial event.

 

Mercury and Venus, after all, don’t even have moons. Mars has a couple, but they’re too small to completely blot out the sun. Gas giants like Jupiter do have big moons, but they don’t have solid surfaces where you could stand and enjoy an eclipse.

 

And, even with solid land and a moon, Earth only gets its gorgeous total solar eclipses because of a cosmic coincidence.

 

“They appear to be the same size because of their distance away from us,” explains Amber Porter, an astronomer at Clemson University, which is in the path of the upcoming eclipse. The diameter of Earth’s moon is about 400 times smaller than the diameter of the sun, but “even though the moon is about 400 times smaller than the sun, it’s about 400 times closer to us here on Earth, which is how that perfect kind of magic happens.”

Because of this quirk, the tiny moon can obscure the entire face of the sun and reveal its eerie corona, at least right now. In the past, Earth’s eclipses did not look like this.

 

“The size of the sun hasn’t really changed over the age of Earth, but the moon has been moving away from Earth over eons. So in the past it looked bigger,” says Matija Cuk, a planetary scientist at the SETI Institute.

 

The moon is still moving away from Earth, he says. Every year, it shifts outward about an inch-and-half…”

 

For the rest, click here.

 

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Cities and farms are far older than we think — 30,000 years older…

Consider this: “…people began altering their environments for food and shelter about 30,000 years earlier than we thought.”

 

30,000 years!

 

 

From arstechnica.com,

 

Paleolithic pastimes —
Evidence that ancient farms had very different origins than previously thought
Dramatic new hypothesis could change the way we understand human history.
by Annalee Newitz

 

“It’s an idea that could transform our understanding of how humans went from small bands of hunter-gatherers to farmers and urbanites. Until recently, anthropologists believed cities and farms emerged about 9,000 years ago in the Mediterranean and Middle East. But now a team of interdisciplinary researchers has gathered evidence showing how civilization as we know it may have emerged at the equator, in tropical forests. Not only that, but people began altering their environments for food and shelter about 30,000 years earlier than we thought.

 

For centuries, archaeologists believed that ancient people couldn’t live in tropical jungles. The environment was simply too harsh and challenging, they thought. As a result, scientists simply didn’t look for clues of ancient civilizations in the tropics. Instead, they turned their attention to the Middle East, where we have ample evidence that hunter-gatherers settled down in farming villages 9,000 years ago during a period dubbed the “Neolithic revolution.” Eventually, these farmers’ offspring built the ziggurats of Mesopotamia and the great pyramids of Egypt. It seemed certain that city life came from these places and spread from there around the world.

 

But now that story seems increasingly uncertain. In an article published in Nature Plants, Max Planck Institute archaeologist Patrick Roberts and his colleagues explain that cities and farms are far older than we think. Using techniques ranging from genetic sampling of forest ecosystems and isotope analysis of human teeth, to soil analysis and lidar, the researchers have found ample evidence that people at the equator were actively changing the natural world to make it more human-centric.

 

It all started about 45,000 years ago. At that point, people began burning down vegetation to make room for plant resources and homes. Over the next 35,000 years, the simple practice of burning back forest evolved. People mixed specialized soils for growing plants; they drained swamps for agriculture; they domesticated animals like chickens; and they farmed yam, taro, sweet potato, chili pepper, black pepper, mango, and bananas.

 

École française d’Extrême-Orient archaeologist Damian Evans, a co-author on the Nature paper, said that it wasn’t until a recent conference brought international researchers together that they realized they’d discovered a global pattern. Very similar evidence for ancient farming could be seen in equatorial Africa, South Asia, and Southeast Asia. Much later, people began building “garden cities” in these same regions, where they lived in low-density neighborhoods surrounded by cultivated land.

 

Evans, Roberts, and their colleagues aren’t just raising questions about where cities originated. More importantly, Roberts told Ars via email, they are challenging the idea of a “Neolithic revolution” in which the shift to city life happened in just a few hundred years…”

 

For the rest, click here.

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Our nearest potentially habitable exoplanet may be a water world…

Water is life….?

 

Credits: AFP

 

From Futurism,

 

One of Earth’s Closest Alien Planets Appears to Be An “Ocean World”

 

The case for Proxima b
“Proxima b’s proximity to Earth — about 4.2 light years away — makes it the nearest exoplanet that is potentially habitable and could contain life. While it may be tidally locked (meaning one side of Proxima b perpetually faces its star as it completes its 11.2 year revolution), Proxima b’s proximity to the star it orbits, the red-dwarf Proxima Centauri, puts it right in the Goldilocks Zone. This means there’s a strong possibility that water exists on this exoplanet.

 

A team from the National Center for Scientific Research (CNRS) in France believes Proxima b may not just contain water; it could be covered in it. “The planet could be an ‘ocean planet’, with an ocean covering its entire surface, and similar water to some icy moons around Jupiter or Saturn,” the team says.

 

Water = Life
To figure out just how much water may be on Proxima b, the CNRS team used simulations that play with the estimated range of the planet’s radius, between 0.94 and 1.4 times that of the Earth. At the lowest limit, the simulations suggest a dense planet with a metallic core surrounded by a rocky mantle, and surface water of about 0.05% of the planet’s total mass.

 

With the maximum limit, however, the simulations show the planet’s radius at 8,920 km (5,542.6 miles), with a mass that’s equally divided between a rocky core and surrounding water. “In this case, Proxima b would be covered by a single, liquid ocean 200 km deep,” the researchers explained…”

 

For the rest, click here.

 

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