Earth Archives

October 31, 2022October 31, 2022 by Carolyn Collins Petersen

Good News! The Ozone Hole is Continuing to Shrink

earth's atmosphere has an ozone hole (not seen here) — Earth’s atmosphere seen from space. The top layer of the stratosphere is the ozone layer, which protects us from harmful solar UV. Scientists are tracking the ozone hole over the Antarctic. Credit: NASA

Most of us don’t think about ozone as we go about our daily lives. Yet, this pale blue gas plays a huge role in keeping our planet habitable. There’s a layer of it in Earth’s stratosphere, and it absorbs most of the ultraviolet radiation streaming from the Sun. Without the ozone layer, the UV would cause severe damage to most life on Earth. What would happen if we had an ozone hole?

October 28, 2022October 28, 2022 by Evan Gough

The Most Devastating Solar Storms in History are Scoured Into Tree Rings

Scientists study tree rings because they retain a record of climatic events and changes. They also record the Sun's activity. Image Credit: Rbreidbrown/Wikimedia Commons, CC BY-SA

Trees are like sentinels that preserve a record of shifting climates. Their growth rings hold that history and dendrochronology studies those rings. Scientists can determine the exact ages of trees and correlate their growth with climatic and environmental changes.

But they also record the effects of more distant changes, including the Sun’s activity.

October 27, 2022October 27, 2022 by Evan Gough

Earth’s Hardiest Bacteria Could Survive Hundreds of Millions of Years Just Under the Surface of Mars

A few years from now, a small capsule will enter Earth’s atmosphere and float to the surface under a parachute. The parachute will likely be radar-reflective so that it can be easily tracked. It may land in Australia’s outback, a popular spot for sample returns. Scientists will take it to a sterilized, secure lab and carefully open it. Inside, there’ll be rock samples from Mars collected by the Perseverance Rover.

If a new study is correct, scientists should look carefully for dormant life in those samples.

October 26, 2022October 26, 2022 by Evan Gough

How Dangerous are Nearby Supernovae to Life on Earth?

A composite image of SN 1987A from Hubble, Chandra, and ALMA. Image Credit: By ALMA (ESO/NAOJ/NRAO)/A. Angelich. Visible light image: the NASA/ESA Hubble Space Telescope. X-Ray image: The NASA Chandra X-Ray Observatory - http://www.eso.org/public/images/eso1401a/, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=30512379

Life and supernovae don’t mix.

From a distance, supernovae explosions are fascinating. A star more massive than our Sun runs out of hydrogen and becomes unstable. Eventually, it explodes and releases so much energy it can outshine its host galaxy for months.

But space is vast and largely empty, and supernovae are relatively rare. And most planets don’t support life, so most supernovae probably explode without affecting living things.

But a new study shows how one type of supernova has a more extended reach than thought. And it could have consequences for planets like ours.

October 25, 2022October 27, 2022 by Nancy Atkinson

Lucy Took This Picture of Earth as it was Making its Gravity Assist Maneuver

NASA’s Lucy spacecraft captured this image of the Earth on Oct 15, 2022 during the spacecraft's flyby of our planet for a gravitational assist on its way to explore the Jupiter Trojan asteroids. Credits: NASA/Goddard/SwRI

We may take it for granted, but every day we receive picture postcards from the robotic travelers we have sent out to explore our Solar System. Usually, we get to see faraway planets, moons, asteroids, or comets. But sometimes we get to see ourselves.

The Lucy spacecraft took a couple of amazing images of our home planet as the spacecraft was approaching Earth for the first of three slingshot gravity assists on its way out to explore the Trojan asteroids along Jupiter’s orbit.

October 14, 2022October 16, 2022 by Evan Gough

If Earth Were an Exoplanet, it Would Still be Tricky to Figure Out if There’s Life Here

Earth as seen by the JUNO spacecraft in 2013. Credit: NASA/JPL-Caltech/SwRI/MSSS/Kevin M. Gill.

How would Earth appear to alien astronomers? What would their observations tell them about Earth if they searched the heavens for signs of habitability like we are? It’s a fun thought experiment.

But the experiment is more than just fun: it’s scientifically instructive. In many ways, it’s easier to study our planet and how it appears and then extrapolate those results as far as they go.

A new study shows that finding evidence of life on Earth may depend on the season alien astronomers are observing.

October 12, 2022October 12, 2022 by Evan Gough

The Moon Might be One Large Chunk that was Blasted Off the Earth Billions of Years Ago

A new study and supercomputer simulations present an alternative explanation for the Moon. Yes, it formed from an impact, but it may not have taken years. Image Credit: NASA Ames Research Center

Where did the Moon come from?

The widely-accepted view is that the Moon is a result of an ancient collision between the young Earth and a Mars-sized planet named Theia about 4.5 billion years ago. The impact melted Earth and Theia and sent molten material into orbit around Earth, where it formed a rotating torus of molten rock. That rock eventually coalesced into the Moon. It’s called the Giant Impact Hypothesis, and isotopic evidence from Apollo moon rocks illustrates the link between Earth and its Moon.

Case closed?

Not so fast. There’ve always been problems with this hypothesis. Can a new study answer them?

October 10, 2022October 10, 2022 by Matt Williams

The Pacific Ocean Will be Gone in 300 Million Years as the World's Continents Drift and Combine

Earth, seen from space, above the Pacific Ocean. Credit: NASA

Today, the Earth’s seven continents are distributed across the surface, with North and South America occupying one hemisphere, Africa, Europe, Asia, and Australia occupying the other, and Antarctica sitting alone around the South Pole. However, these continents were arranged in entirely different configurations throughout Earth’s history. On occasion, they formed supercontinents like Gondwana (ca. 550 to 180 million) and Pangaea (ca. 335 to 200 million years ago) that were surrounded by “superoceans.”

Eventually, the Earth’s tectonic plates will come together again to form the world’s next supercontinent. According to new research led by Curtin University in Bentley, Australia, this will happen roughly 200 to 300 million years from now. As they determined through a series of simulations, this will involve the Americas drifting westward until they collide with Australia and Asia (eliminating the Pacific Ocean) and Antarctica moving north to join them. This will give rise to the new supercontinent they have named “Amasia,” which will also have profound implications for life on Earth.

October 8, 2022October 8, 2022 by Nancy Atkinson

The Methane Released From the Damaged Nord Stream Pipeline is Visible From Space

On September 20, 2022 a GHGSat satellite observed the area of the Nordstream pipeline break, and saw an estimated emission rate of methane of 79,000 kg per hour – making it the largest methane leak ever detected by GHGSat from a single point-source. Credit: GHGSat and ESA.

On September 26, 2022, leaks were discovered in the underwater Nord Stream 1 and 2 gas pipelines, located near Denmark and Sweden. Both pipelines are owned by Russia and were built to transport natural gas from Russia to Germany through the Baltic Sea. Officials have said the leaks were caused by deliberate action, not accidents, and were likely intentional sabotage. While accusations have abounded, the motives behind the damage are not yet known.

Seismic disturbances in the Baltic Sea were detected, and officials said that while neither pipeline was transporting gas at the time of the blasts, they still contained pressurized methane, which is the main component of natural gas. The methane has now spewed out, producing a wide stream of bubbles on the sea surface which are visible from various satellites in Earth orbit.

October 3, 2022October 3, 2022 by Nancy Atkinson

Gaze Down Into the eye of Hurricane Ian, Seen From Orbit

On September 28, the Landsat 8 satellite passed directly over Ian’s eye as the storm approached southwest Florida. Credit: US Geological Survey.

NASA and NOAA satellites — as well as astronauts on the ISS — captured some stunning imagery of Hurricane Ian, as seen from orbit. Our lead image shows an eerie view of the hurricane’s eye on September 28. The Landsat 8 satellite passed directly over Ian’s eye as the storm approached southwest Florida.