3 Billion Years Ago, the World Might Have Been a Waterworld, With No Continents At All

Artist's depiction of a waterworld. A new study suggests that Earth is in a minority when it comes to planets, and that most habitable planets may be greater than 90% ocean. Credit: David A. Aguilar (CfA)

Evidence from an ancient section of the Earth’s crust suggest that Earth was once a water-world, some three billion years ago. If true, it’ll mean scientists need to reconsider some thinking around exoplanets and habitability. They’ll also need to reconsider their understanding of how life began on our planet.

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The Moon’s Magnetosphere Used to be Twice as Strong as the Earth’s

For decades, scientists have held that the Earth-Moon system formed as a result of a collision between Earth and a Mars-sized object roughly 4.5 billion years ago. Known as the Giant Impact Hypothesis, this theory explains why Earth and the Moon are similar in structure and composition. Interestingly enough, scientists have also determined that during its early history, the Moon had a magnetosphere – much like Earth does today.

However, a new study led by researchers at MIT (with support provided by NASA) indicates that at one time, the Moon’s magnetic field may have actually been stronger than Earth’s. They were also able to place tighter constraints on when this field petered out, claiming it would have happened about 1 billion years ago. These findings have helped resolve the mystery of what mechanism powered the Moon’s magnetic field over time.

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It’s Snowing Iron Near the Earth’s Core

The Earth's layers, showing the Inner and Outer Core, the Mantle, and Crust. Credit: discovermagazine.com

Scientists theorize that within Earth’s interior, conditions are extremely hot and extremely pressurized. This is what allows for the primarily iron and nickel core to be divided between a solid inner region and liquid outer region. The dynamics of this core are believed to be responsible for driving our planet’s protective magnetosphere, which is why scientists are determined to improve their understanding of it.

Thanks to new research conducted by an international team of scientists, it appears that the core region also gets its fair share of “snow”! To put it another way, their research showed that within the outer core, tiny particles of iron solidify and fall to form piles up to 320 km (200 mi) thick on top of the outer core. These findings could vastly improve our understanding of the forces that affect the entire planet.

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Science Fiction Might Be Right After All. There Might Be Breathable Atmospheres Across the Universe

This view of Earth’s horizon was taken by an Expedition 7 crewmember onboard the International Space Station, using a wide-angle lens while the Station was over the Pacific Ocean. A new study suggests that Earth's water didn't all come from comets. Credit: NASA

The last few years has seen an explosion of exoplanet discoveries. Some of those worlds are in what we deem the “habitable zone,” at least in preliminary observations. But how many of them will have life-supporting, oxygen-rich atmospheres in the same vein as Earth’s?

A new study suggests that breathable atmospheres might not be as rare as we thought on planets as old as Earth.

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Landslides Work Differently on Mars, and Now We Might Know Why

Some landslides, both here on Earth and on Mars, behave in a puzzling way: They flow a lot further than friction should allow them too.

They can also be massive, including a well-preserved one in Valles Marineris that is the same size as the state of Rhode Island. Scientists have speculated that it might be so large because a layer of ice that existed in the past provided lubrication. But a new study suggests that no ice is needed to explain it.

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Giant Meteor Impacts Might Have Triggered Early Earth’s Plate Tectonics

Plate tectonics have played a vital role in the geological evolution of our planet. In addition, many scientists believe that Earth’s geologically activity may have played an important role in the evolution of life – and could even be essential for a planet’s habitability. For this reason, scientists have long sought to determine how and when Earth’s surface changed from molten, viscous rock to a solid crust that is constantly resurfacing.

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There Could be Planets Out There Which are Even More Habitable than Earth

When searching for potentially habitable exoplanets, scientists are forced to take the low-hanging fruit approach. Since Earth is the only planet we know of that is capable of supporting life, this search basically comes down to looking for planets that are “Earth-like”. But what if Earth is not the meter stick for habitability that we all tend to think it is?

That was the subject of a keynote lecture that was recently made at the Goldschmidt Geochemistry Congress, which took place from Aug. 18th to 23rd, in Barcelona, Spain. Here, a team of NASA-supported researchers explained how an examination of what goes into defining habitable zones (HZs) shows that some exoplanets may have better conditions for life to thrive than Earth itself has.

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Fossilized Clams Had Evidence of a Meteorite Impact Inside Them

When an extraterrestrial object slams into the Earth, it sends molten rock high into the atmosphere. That debris cools and re-crystallizes and falls back down to Earth. Tiny glass beads that form in this process are called microtektites, and researchers in Florida have found microtektites inside fossilized clams.

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1.2 billion years ago, a 1-km asteroid smashed into Scotland

In 2008, scientists from Oxford and Aberdeen University made a startling discovery in the northwest of Scotland. Near the village of Ullapool, which sits on the coast opposite the Outer Hebrides, they found a debris deposit created by an ancient meteor impact dated to 1.2 billion years ago. The thickness and extent of the debris suggested that the meteor measured 1 km (0.62 mi) in diameter and took place near to the coast.

Until recently, the precise location of the impact remained a mystery to scientists. But in a paper that recently appeared in the Journal of the Geological Society , a team of British researchers concluded that the crater is located about 15 to 20 km (~9 to 12.5 mi) west of the Scottish coastline in the Minch Basin, where it is buried beneath both water and younger layers of rock.

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Rovers on Mars should be searching for rocks that look like pasta – they’re almost certainly created by life

According to a new NASA-funded study that appeared in Astrobiology, the next missions to Mars should be on the lookout for rocks that look like “fettuccine”. The reason for this, according to the research team, is that the formation of these types of rocks is controlled by a form of ancient and hardy bacteria here on Earth that are able to thrive in conditions similar to what Mars experiences today.

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