Earth Archives

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.

October 22, 2024October 22, 2024 by Evan Gough

This Early Impact Devastated Life then Gave it a Boost

This graphic depicts what happened when the S2 meteorite struck Earth about 3.26 billion years ago. Initially, it was devastating but eventually it lead to mass blooms. Image Credit: Drabon et al. 2024.

Most of us know about the impact that wiped out the dinosaurs about 66 million years ago. It’s a scientific fact that’s entered mainstream knowledge, maybe because so many of us shared a fascination with dinosaurs as children. However, it’s not the only catastrophic impact that shaped life on Earth.

There was an even more ancient one about 3.26 billion years ago, and its repercussions shaped early life in a unique way.

October 18, 2024October 18, 2024 by Evan Gough

The Sun Has Reached Its Solar Maximum and it Could Last for One Year

These extreme UV light images from the Solar Dynamics Observatory shows the Sun at solar minimum (left, Dec. 2019) compared to the current solar maximum. Image Credit: NASA/SDO

For most of human history, the Sun appeared stable. It was a stoic stellar presence, going about its business fusing hydrogen into helium beyond our awareness and helping Earth remain habitable. But in our modern technological age, that facade fell away.

We now know that the Sun is governed by its powerful magnetic fields, and as these fields cycle through their changes, the Sun becomes more active. Right now, according to NASA, the Sun is at its solar maximum, a time of increased activity.

September 24, 2024September 24, 2024 by Evan Gough

How a Nearby Supernova Left its Mark on Earth Life

Artist's impression of a supernova. Supernovae bombarded Earth with radiation that has implications for the development of life on Earth. Image Credit: NASA

When a massive star explodes as a supernova, it does more than release an extraordinary amount of energy. Supernovae explosions are responsible for creating some of the heavy elements, including iron, which is blasted out into space by the explosion. On Earth, there are two accumulations of the iron isotope Fe60 in sea-floor sediments that scientists trace back about two or three million years ago and about five to six million years ago.

The explosions that created the iron also dosed Earth with cosmic radiation.

September 23, 2024September 23, 2024 by Mark Thompson

What Happens to the Climate When Earth Passes Through Interstellar Clouds?

Orion Molecular Cloud Complex, dominated in the center of this view by the brilliant Flame nebula (NGC 2024). The smaller, glowing cavity falling between the Flame nebula and the Horsehead is called NGC 2023. Image credit: NASA/JPL-Caltech.

Noctilucent clouds were once thought to be a fairly modern phenomenon. A team of researcher have recently calculated that Earth and the entire Solar System may well have passed through two dense interstellar clouds causing global noctilucent clouds that may have driven an ice age. The event is thought to have happened 7 million years ago and would have compressed the heliosphere, exposing Earth to the interstellar medium.

September 23, 2024September 23, 2024 by Evan Gough

From Frozen to Sweltering: Earth’s Climate Over the Last 485 Million Years

New research shows the global mean surface temperature across the last 485 million years. The gray shading corresponds to different confidence levels, and the black line shows the average. The colored bands along the top reflect the climate state, with cooler colors indicating icehouse (coolhouse and coldhouse) climates, warmer colors indicating greenhouse (warmhouse and hothouse) climates, and the gray representing a transitional state. Image Credit: Judd et al. 2024.

Earth’s last half-billion years were action-packed. During that time, the climate underwent many changes. There have been changes in ocean levels and ice sheets, changes in the atmosphere’s composition, changes in ocean chemistry, and ongoing biological evolution punctuated with extinction events.

A record of Earth’s temperature over the last 485 million years is helping scientists understand how it all played out and illustrating what could happen if we continue to enrich the atmosphere with carbon.