North and South America, At Night

Composite image of the Americas at night from the Suomi NPP satellite. Image Credit: NASA

Along with all of their space-exploration, planet-hunting, and astronomy-based endeavours, NASA also keeps a very keen eye on Earth. In fact, they have 18 satellites whose job it is to look only at Earth. And those 18 advanced satellites are helping us understand Earth in unprecedented scientific detail.

And they take pretty pictures, too.

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We Know We’re Made of Stardust. But Did it Come From Red Giants?

Artist's impression of a red giant star. If the star is in a binary pair, what happens to its sibling? Credit:NASA/ Walt Feimer

We’ve all heard this one: when you drink a glass of water, that water has already been through a bunch of other people’s digestive tracts. Maybe Attila the Hun’s or Vlad the Impaler’s; maybe even a Tyrannosaurus Rex’s.

Well, the same thing is true of stars and matter. All the matter we see around us here on Earth, even our own bodies, has gone through at least one cycle of stellar birth and death, maybe more. But which type of star?

That’s what a team of researchers at ETH Zurich (Ecole polytechnique federale de Zurich) wanted to know.

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

Erosion on Mars. Image Credit: NASA/JPL/UA/HiRise

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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A Brand New Island in the Pacific has Survived 5 Years

Hunga Tonga-Hunga Ha‘apai with the ship SSV Robert C. Seamans. Image Credit: Captain Chris Nolan (Sea Education Association) of the SSV Robert C. Seamans (Oct. 2019).

A surtseyan eruption is a volcanic eruption in shallow water. It’s named after the island Surtsey, off the coast of iceland. In 2015, a surtseyan eruption in the Tongan Archipelago created the island Hunga Tonga-Hunga Ha‘apai. Despite the odds, that island is still there almost five years later.

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Time-lapse Captured from the International Space Station

Time lapse photography from astronaut Christina Koch aboard the ISS. Image Credit: ISS Crew Earth Observations Facility and the Earth Science and Remote Sensing Unit.

400 photos. 11 minutes. That’s what it took to create this time-lapse of the Earth and stars as the International Space Station over Namibia toward the Red Sea. NASA astronaut Christina Koch captured these images.

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Weekly Space Hangout: October 16, 2019 – Jeffrey Kargel Talks Climate Change on Earth and Beyond

Hosts:
Fraser Cain (universetoday.com / @fcain)

Allen Versfeld (https://www.urban-astronomer.com/ / @uastronomer)

Dr. Morgan Rehnberg (MorganRehnberg.com / @MorganRehnberg & ChartYourWorld.org)

Moiya McTier (https://www.moiyamctier.com/ / @GoAstroMo)

Jeff Kargel is a Senior Scientist at the Planetary Science Institute in Tucson, Arizona. He is a geologist, a glaciologist, and a planetary scientist. Climate change is a major thread, and that is what he is here today to talk about.

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Confirmed. Fossils That Formed 3.5 billion Years Ago, Really are Fossils. The Oldest Evidence of Life Found So Far

A stromatolite from the Pilbara Craton in Australia. Image Credit: By Didier Descouens - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=15944367

The title of Earth’s Earliest Life has been returned to the fossils in the Pilbara region of Australia. The Pilbara fossils had held that title since the 1980s, until researchers studying ancient rocks in Greenland found evidence of ancient life there. But subsequent research questioned the biological nature of the Greenland evidence, which put the whole issue into question again.

Now a new study of the Pilbara fossils has identified the presence of preserved organic matter in those fossils, and handed the ‘Ancient Life’ crown back to them.

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A Distant Asteroid Collision Gave Earthly Biodiversity An Ancient Boost

An artist's illustration of the Ordovician Meteor Event. Image Credit: DON DAVIS, SOUTHWEST RESEARCH INSTITUTE

About 466 million years ago, there was an asteroid collision in the asteroid belt between Mars and Jupiter. The collision caused the breakup of a major asteroid, creating a shower of dust throughout the inner Solar System. That event is called the Ordovician Meteor Event, and its dust caused an ice age here on Earth.

That ice age contributed to an enormous boost in biodiversity on ancient Earth.

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The Moon is Older Than Scientists Thought

It is believed that 4.4 billion years ago, a celestial body (Theia) slammed into Earth and produced the Moon. Image Credit: NASA/JPL-Caltech

The most comprehensive and widely-held theory of how the Moon formed is called the ‘giant impact hypothesis.’ That hypothesis shows that about 150 million years after the Solar System formed, a roughly Mars-sized planet named Theia collided with Earth. Though the timeline is hotly-debated in the scientific community, we know that this collision melted Theia and some of Earth, and that molten rock orbited around Earth until it coalesced into the Moon.

But now a new study, though not contradicting the giant impact hypothesis, is suggesting a different timeline, and an older Moon.

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There’s A Fire in Greenland… Again. It’s 10 Degrees Hotter Than Normal

This fire in Greenland is near Sisimiut, in Western Greenland. It was likely caused by a hiker. Image Credit: NASA Earth Observatory

As global warming ramps up, expect to see Greenland in the news a lot. That’s because its ice sheet is under threat of melting. But that’s not the only reason. The other reason is fire.

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