Earth Archives

December 12, 2024December 12, 2024 by Brian Koberlein

Early Earth's Oceans of Magma Accelerated the Moon's Departure

Illustration of the exoplanet Corot-7b, which may have lava oceans. Credit: ESO/L. Calçada

The Earth and Moon have been locked in a gravitational dance for billions of years. Each day, as the Earth turns, the Moon tugs upon the oceans of the world, causing the rise and fall of tides. As a result, the Earth’s day gets a little bit longer, and the Moon gets a little more distant. The effect is small, but over geologic time it adds up. About 620 million years ago, a day on Earth was only 22 hours long, and the Moon was at least 10,000 km closer than it is now.

December 6, 2024December 6, 2024 by Evan Gough

Advanced Civilizations Could be Indistinguishable from Nature

The Search for Extraterrestrial Intelligence. Image Credit: SETI

Sometimes in science you have to step back and take another look at underlying assumptions. Sometimes its necessary when progress stalls. One of the foundational questions of our day concerns the Fermi Paradox, the contradiction between what seems to be a high probability of extraterrestrial life and the total lack of evidence that it exists.

What assumptions underlie the paradox?

December 3, 2024December 3, 2024 by Evan Gough

Antarctica Has Gotten 10 Times Greener in 35 Years

Antarctica is becoming greener due to climate change. Image Credit: Michala Garrison, based on data from Roland, T.P., et al. (2024).

Our satellites are dispassionate observers of Earth’s climate change. From their vantage point they watch as pack ice slowly loses its hold on polar oceans, ice shelfs break apart, and previously frozen parts of the planet turn green with vegetation.

Now, scientists have compiled 35 years of satellite data showing that Antarctica is slowly, yet perceptibly, becoming greener.

November 29, 2024November 29, 2024 by Mark Thompson

The Early Earth Wasn’t Completely Terrible

Earth formed 4.54 billion years ago. The first period of the history of the Earth was known as the Hadean Period which lasted from 4.54 billion to 4 billion years ago. During that time, Earth was thought to be a magma filled, volcanic hellscape. It all sounds rather inhospitable at this stage but even then, liquid oceans of water are thought to have existed under an atmosphere of carbon dioxide and nitrogen. Recent research has shown that this environment may well have been rather more habitable than once thought.

November 22, 2024November 22, 2024 by Evan Gough

Earth’s Old Trees Keep A Record of Powerful Solar Storms

A solar flare erupts on the Sun. Credit: NASA/GSFC/SDO

Most of the time the Sun is pretty well-mannered, but occasionally it’s downright unruly. It sometimes throws extremely energetic tantrums. During these events, a solar flare or a shock wave from a coronal mass ejection (CME) accelerates protons to extremely high velocities. These are called Solar Particle Events or Solar Proton Events (SPEs).

However, the exact timing of these events can be difficult to ascertain. New research has determined the date of one of the most powerful SPEs to strike Earth during the Holocene.

November 13, 2024November 13, 2024 by Evan Gough

Lessons From Ancient Earth’s Atmosphere: From Hostile to Hospitable

Earth's ancient atmosphere was much different than now. How did it transition from hostile to hospitable? If scientists can figure that out, they'll be better able to understand exoplanets and their atmospheres. Image Credit: Tohoku University

Will we ever understand how life got started on Earth? We’ve learned much about Earth’s long, multi-billion-year history, but a detailed understanding of how the planet’s atmospheric chemistry evolved still eludes us. At one time, Earth was atmospherically hostile, and its transition from that state to a planet teeming with life followed a complex path.

November 12, 2024November 12, 2024 by Evan Gough

An Otherworldly Cloud Over New Zealand

Landsat 8’s Operational Land Imager captured this unique lenticular cloud that forms over the Otago region of New Zealand’s South Island. Image Credit: NASA/Lauren Dauphin; USGS

Filmmakers love New Zealand. Its landscapes evoke other worlds, which explains why so much of The Lord of the Rings was filmed there. The country has everything from long, subtropical sandy beaches to active volcanoes.

The country’s otherworldliness extends into its atmosphere, where a cloud nicknamed the “Taieri Pet” forms when conditions are right.

November 11, 2024November 11, 2024 by Mark Thompson

Good News, the Ozone Layer Hole is Continuing to Shrink

The area of depleted ozone over the Antarctic ranked the seventh smallest since recovery began in 1992.

Climate change is a huge topic and often debated across the world. We continue to burn fossil fuels and ignore our charge toward human driven climate change but while our behaviour never seems to improve, something else does! For the last few decades we have been pumping chlorofluorocarbons into the atmosphere causing a hole in the ozone layer to form. Thanks largely to worldwide regulation changes and a reduction in the use of these chemicals, the hole it seems is finally starting to get smaller.

October 31, 2024October 31, 2024 by Evan Gough

This is What it Sounds Like When the Earth’s Poles Flip

Ever wondered what a geomagnetic excursion sounds like? The ESA does. Image Credit: ESA

Is there something strange and alien confined deep inside the Earth? Is it trying to break free and escape into the heavens? No, of course not.

But in a new soundscape from the ESA, it sure sounds like it.

October 24, 2024October 24, 2024 by Evan Gough

Did Some of Earth’s Water Come from the Solar Wind?

The Sun releases a steady stream of charged particles called the Solar Wind. When it strikes unprotected surfaces like asteroids or the Moon, it can change the chemistry and even create water molecules. Image Credit: NASA’s Goddard Space Flight Center/Mary Pat Hrybyk-Keith

The source of Earth’s water is an enduring mystery that extends to exoplanets and the notion of habitability. In broad terms, Earth’s water was either part of the planet from the beginning of its formation in the solar nebula or delivered later, maybe by asteroids and comets.

New research suggests that the Sun’s relentless solar wind could’ve played a role.