What Cracked the Earth’s Outer Shell and Started its Plate Tectonics?

Earth’s lithosphere is made up of seven large tectonic plates and a number of smaller ones. The theory of plate tectonics that describes how these plates move is about 50 years old. But there’s never really been an understanding of how this system developed, and how the Earth’s shell split into separate plates and started moving.

Now a group of researchers have a possible explanation.

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800 Million Years Ago, it Was Raining Asteroids on the Earth and Moon

Natural processes here on Earth continually re-shape the planet’s surface. Craters from ancient asteroid strikes are erased in a short period of time, in geological terms. So how can researchers understand Earth’s history, and how thoroughly it may have been pummeled by asteroid strikes?

Scientists can turn their attention to our ancient companion, the Moon.

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Dust Seen Streaming Out of Namibia Into the Atlantic Ocean

Landsat 8 strikes again.

Landsat 8 is the United States Geological Survey’s most recently launched satellite, and it holds the powerful Operational Land Imager (OLI.) The OLI is a powerful multi-spectral imager with a wide dynamic range.

The OLI does a great job of keeping an eye on Earth, and now its captured images of winds in Namibia picking dust up and carrying it out over the Atlantic Ocean.

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Mount Everest, Seen from Space!

One under-appreciated space asset is the photography skills of the Russian cosmonauts on board the International Space Station. They are extremely skillful photographers who don’t get the same recognition as their astronaut counterparts in their Earth observation skills. In particular, they have taken some stunning high-oblique shots of objects close to the horizon, with almost an 3-D effect.

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Watch the Incredible Plume of Dust from Africa Cross the Entire Atlantic Ocean

Dust plumes are a natural phenomena, part of Earth’s nutrient cycle. They occur when high-velocity winds pick up tiny dry particles from the Earth’s surface and carry them long distances. Every summer, dust plumes from Africa’s Sahara desert travel across the Atlantic Ocean.

They’re usually not this big, and they often sink into the ocean. But this one’s coming right to America.

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Even If We Cut Greenhouse Gas Emissions Tomorrow, it Would Take Decades for the Earth to Start Cooling Again

Our beautiful, precious, life-supporting Earth as seen on July 6, 2015 from a distance of one million miles by a NASA scientific camera aboard the Deep Space Climate Observatory spacecraft. Credits: NASA

If—or hopefully when—we cut our Greenhouse Gas (GHG) emissions, we won’t notice much difference in the climate. The Earth’s natural systems take time to absorb carbon from the atmosphere. We may have to wait decades for the temperatures to drop.

Of course, that doesn’t mean we shouldn’t do it. It’s just that we have to temper our expectations a little.

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It Was Almost Certainly an Asteroid Impact that Wiped Out the Dinosaurs. In Fact, Volcanoes Might Have Helped Life Recover

It seems almost certain that an asteroid impact wiped out the dinosaurs. But only almost. Another competing theory won’t completely go away: the extinction-by-volcano theory.

A new study from the UK piles more evidence on the asteroid side of the debate, while adding a new volcanic twist. These researchers say that volcanic activity actually helped life recover from the asteroid strike.

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Last Year’s Total Solar Eclipse on Earth, Seen From the Moon

On July 2, 2019, the Moon cast its shadow on the surface of the Earth. This time, the shadow’s path travelled across the South Pacific Ocean. It also passed over some of Argentina and Chile. For surface dwellers in the path, the Moon briefly blocked the Sun, turning night into day.

But for one “eye” in orbit around the Moon, the view was different. A camera on a tiny satellite watched as the circular shadow of the Moon moved over the Earth’s surface.

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