Science Megathread

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We may not be the main guilty party in the mass extinction of Ice Age megafauna, it seems:

Ice core data supports ancient space impact idea

By Simon Redfern
Reporter, BBC News

A layer of platinum is seen in ice of the same age as a known abrupt climate transition, US scientists report.

The climate flip has previously been linked to the demise of the North American "Clovis" people.

The data seem to back the idea that an impact tipped the climate into a colder phase, a point of current debate.

Rapid climate change occurred 12,900 years ago, and it is proposed that this is associated with the extinction of large mammals - such as the mammoth, widespread wildfires and rapid changes in atmospheric and ocean circulation.

All of these have previously been linked to a cosmic impact but the theory has been hotly disputed because there was a lack of clear evidence.

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NASA apparently decided to call it quits on trying to fix the Kepler Planet Hunter.

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Thanks to radar, we now know that Greenland contains a canyon bigger than that of the better-known Grand Canyon in Arizona.

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By 'early-Cretaceous', the author probably meant this particular asteroid hit in the late Eocene -the Cretaceous ended 65 million years ago:

Seawater discovered near the Chesapeake Bay is up to 150 million years old

By Darryl Fears, Published: November 16

Not only is the Chesapeake Bay so enormous it can be seen from space, it essentially came from outer space.



An asteroid or huge chunk of ice slammed into Earth about 35 million years ago, splashing into the Early Cretaceous North Atlantic, sending tsunamis as far as the Blue Ridge Mountains and leaving a 56-mile-wide hole at the mouth of what is now the bay.

But a newly published research paper written by U.S. Geological Survey scientists shows that wasn’t the end of it. While drilling holes in southern Virginia to study the impact crater, the scientists discovered “the oldest large body of ancient seawater in the world,” a survivor of that long-gone sea, resting about a half-mile underground near the bay, according to the USGS.

“What we essentially discovered was trapped water that’s twice the salinity of [modern] seawater,” said Ward Sanford, a USGS hydrologist. “In our attempt to find out the origin, we found it was Early Cretaceous seawater. It’s really water that’s from the North Atlantic.”

The findings showing that the water is probably between 100 million and 150 million years old were published Thursday in the journal Nature.

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Also, the domesticated dog likely had a European ancestor that is now extinct.

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DNA indicates Eurasian roots for Native Americans, new study says

By Meeri Kim, Published: November 20

The genetic analysis of a 24,000-year-old arm bone from an ancient Siberian boy suggests that Native Americans have a more complicated ancestry than scientists realized, with some of their distant kin looking more Eurasian than East Asian.

The new study, published online Wednesday in the journal Nature, represents the oldest genome of a modern human ever fully sequenced.

Modern-day Native Americans share from 14 to 38 percent of their DNA with the Siberian hunter-gatherers — who are not closely related to East Asians — with the remainder coming from East Asian ancestors. Most scientists have thought that the first Americans came only from the East Asian populations.

“If you read about the origins of Native Americans, it will say East Asians somehow crossed the Bering Sea,” said study author and evolutionary biologist Eske Willerslev at Copenhagen University. “This is definitely not the case — it’s more complex than that.”

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Lakes discovered beneath Greenland Ice Sheet

Published 28 Nov 2013

The study, published in Geophysical Research Letters, discovered two subglacial lakes 800 metres below the surface of the Greenland Ice Sheet. The two lakes are each roughly 8-10 km2, and at one point may have been up to three times larger than their current size.

Subglacial lakes are likely to influence the flow of the ice sheet which, in turn, impacts global sea-level change. The discovery of the lakes in Greenland will also help researchers to understand how the ice will respond to changing environmental conditions.

The study, conducted at the Scott Polar Research Institute (SPRI) at the University of Cambridge, used airborne radar measurements to reveal the lakes underneath the ice sheet.

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Also, an Indian probe has begun its journey to Mars.

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Severe droughts out west could hamper the water supply in rural areas.

It could get even worse:

Scientists: Past California droughts have lasted 200 years



SAN JOSE, Calif. — California's current drought is being billed as the driest period in the state's recorded rainfall history. But scientists who study the West's long-term climate patterns say the state has been parched for much longer stretches before that 163-year historical period began.

And they worry that the "megadroughts" typical of California's earlier history could come again.

Through studies of tree rings, sediment and other natural evidence, researchers have documented multiple droughts in California that lasted 10 or 20 years in a row during the past 1,000 years — compared to the mere three-year duration of the current dry spell. The two most severe megadroughts make the Dust Bowl of the 1930s look tame: a 240-year-long drought that started in 850 and, 50 years after the conclusion of that one, another that stretched at least 180 years.

"We continue to run California as if the longest drought we are ever going to encounter is about seven years," said Scott Stine, a professor of geography and environmental studies at Cal State East Bay. "We're living in a dream world."

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Here is a recently released night-time image of Earth from Mars, courtesy of our hardy rover, Curiosity:



source

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More space news -Europe's star surveyor, Gaia, has taken up its observation post above the Earth, and is set to begin its mission of making an extremely precise 3D map of our Milky Way Galaxy:

Gaia 'billion-star surveyor' returns test image



By Jonathan Amos
Science correspondent, BBC News

Europe's billion-star surveyor, Gaia, is on track to begin operations in the next two or three months.

Launched in December, the satellite has now taken up its observing station some 1.5 million km from Earth.

Engineers are currently commissioning Gaia's two telescopes and its three instruments, getting them ready to begin mapping the precise positions and motions of one-thousand-million stars.

As part of that process, an image has been produced of a small star cluster.

This grouping is sited in the Large Magellanic Cloud (LMC), a companion galaxy to our own Milky Way, some 160,000 light-years in the distance.

If the picture just released by the European Space Agency looks somewhat underwhelming, that is not really surprising - taking pretty vistas of the sky is not what this mission is about.

Rather, Gaia's job when operational will be to track and characterise points of light moving across its big camera detector - be those stars, asteroids, comets or the flashes generated by exploding objects such as supernovae - to work out how far away they are and how they are moving in relation to everything else.
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http://www.bbc.co.uk/news/science-environment-26073173

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We're one step closer to developing nuclear fusion energy:

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Detection of Waves in Space Buttresses Landmark Theory of Big Bang

By DENNIS OVERBYE
MARCH 17, 2014

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In case anyone's interested:

A group of scientists have found, based on their study of 13,000 years-old nanodiamonds spread across from North America to Europe, that the cause of the Younger Dryas period was due to a comet impact that played a key role in the extinctions of the classic megafauna we all associate with the Ice Age -mammoths, cave bears, woolly rhinos, giant ground sloths, saber-toothed cats, etc.

  

We apparently helped them along...

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That theory has been around awhile, but there are quite a few skeptics.

http://en.wikipedia.org/wiki/Younger_Dryas_impact_hypothesis

Do you think this latest study helps validate that hypothesis? 

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About half of all the water on Earth is older even than the Sun.  

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First carbon-capture plant opens in Saskatchewan, Canada.

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World's largest asteroid impact zone believed uncovered by ANU researchers in central Australia

By Clarissa Thorpe
Updated about 3 hours ago

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This is the area in question:

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The verdict is in:

New DNA Results Show Kennewick Man Was Native American

JUNE 18, 2015

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We're all gonna die, basically:

Earth 'entering new extinction phase' - US study

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New model of cosmic stickiness favors “Big Rip” demise of universe



by David Salisbury | Jun. 30, 2015, 2:12 PM

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Scientists suggest a new, earth-shaking twist on the demise of the dinosaurs

By Joel Achenbach
October 1 at 2:00 PM

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NASA (among other federal agencies) fared well from the recently signed omnibus spending bill:

NASA RECEIVES SIGNIFICANT BUDGET BOOST FOR FISCAL YEAR 2016

18 Dec , 2015   by Ken Kremer

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An increase in funding for NASA is a good thing, but that budget is nowhere near what it should be. At this point, I don't think it would be a bad idea to partially put NASA under the jurisdiction of the DOD and create a United States Space Force. I can only imagine what NASA would be with 10x current funding. To me, the prospects are only exciting.

Isn't there a treaty forbidding weapons in space? 

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Isn't there a treaty forbidding weapons in space?

There is the Outer Space Treaty of 1967. I am unaware of its limitations. However, to the extent its limitations prevent technological advancement, I would support withdrawal and full acceleration of the militarization of space (though perhaps that's a debate for another board).

Just did some preliminary readings on it, and it appears to only forbid weapons of mass destruction being used in outer space -which effectively takes the option of blasting incoming killer asteroids with nuclear weapons out of contention. 

Conventional weapons though, are good.  I'm assuming laser weapons (if we ever get around to developing weapons as futuristic as anything seen in Star Wars) fall under that broad category.