Earth Archives

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 18, 2022October 18, 2022 by Evan Gough

Scientists Discover a New Way Exoplanets Could Make Oxygen; Unfortunately, it Doesn’t Require Life

Oxygen is a valuable biosignature because Earth is oxygen-rich, and because life made all that oxygen. But if we find oxygen in an exoplanet atmosphere does that mean life made it? Or is there an abiotic source of oxygen? Image Credit: NASA

Finding oxygen in an exoplanet’s atmosphere is a clue that life may be at work. On Earth, photosynthetic organisms absorb carbon dioxide, sunlight, and water and produce sugars and starches for energy. Oxygen is the byproduct of that process, so if we can detect oxygen elsewhere, it’ll generate excitement. But researchers have also put pressure on the idea that oxygen in an exoplanet’s atmosphere indicates life. It’s only evidence of life if we can rule out other pathways that created the oxygen.

But scientists can’t rule them out.

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 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 7, 2022October 7, 2022 by Laurence Tognetti

The Moon is the Perfect Spot for Humanity’s Offsite Backup

In a recent study, a collaborative team of researchers discuss the potential for future lunar settlers to establish a backup data storage system of human activity in the event of a global catastrophe on Earth that could be used to recover human civilization on a post-catastrophe planet. This comes as NASA’s Artemis missions plan to send people back to the Moon for the first time since 1972, coupled with current global events such as the ongoing coronavirus pandemic and the War in Ukraine, with Russian President Vladimir Putin recently threatening nuclear war. Given the current state of world affairs, how important is it to establish a type of off-world data backup?

October 3, 2022October 3, 2022 by Evan Gough

Scientists Have Been Underestimating the Asteroid That Created the Biggest Known Crater on Earth

South Africa's Vredefort Crater is Earth's largest impact crater. New Research clarifies the power of the impact and its catastrophic effects. Image Credit: NASA Earth Observatory image by Lauren Dauphin / University of Rochester illustration by Julia Joshpe

Ancient impacts played a powerful role in Earth’s complex history. On other Solar System bodies like the Moon or Mercury, the impact history is preserved on their surfaces because there’s nothing to erase it. But Earth’s geologic activity has erased the evidence of impact craters over time, with some help from erosion.

Earth’s complex history has elevated its status among its Solar System siblings and created a world that’s rippling with life. Ancient giant impacts have played a role in that history, bringing catastrophe and disruption and irrevocably changing the course of events. Deciphering the role these giant impacts played is difficult since the evidence is missing or severely degraded. So how do scientists approach this problem?

One crater at a time.

September 14, 2022September 14, 2022 by Matt Williams

Mars did Have Moving Glaciers, but They Behaved Differently in the Planet's Lower Gravity

Glacial landscapes on Axel Heiberg Island (Canadian Arctic Archipelago) showing typical (glaciers) and atypical (subglacial channels, bottom right) glacial landscapes. Credit: A. Grau Galofre

On Earth, shifts in our climate have caused glaciers to advance and recede throughout our geological history (known as glacial and inter-glacial periods). The movement of these glaciers has carved features on the surface, including U-shaped valleys, hanging valleys, and fjords. These features are missing on Mars, leading scientists to conclude that any glaciers on its surface in the distant past were stationary. However, new research by a team of U.S. and French planetary scientists suggests that Martian glaciers did move more slowly than those on Earth.

June 24, 2022June 24, 2022 by Laurence Tognetti

More Rocket Launches Could Damage the Ozone Layer

There are few things in this world that brings feelings of awe and wonder more than a rocket launch. Watching a literal tower of steel slowly lift off from the ground with unspeakable power reminds us of what humanity can achieve despite our flaws, disagreements, and differences, and for the briefest of moments these magnificent spectacles are capable of bringing us all together regardless of race, creed, and religion.

June 13, 2022June 13, 2022 by Evan Gough

The Rapid Changes We’re Seeing With the Earth’s Magnetic Field Don’t Mean the Poles are About to Flip. This is Normal

An illustration of Earth's magnetic field. Image Credit: ESA/ATG medialab

One of the most interesting discoveries about Earth in the past few decades concerns the Earth’s magnetic poles. Paleomagnetic records show that the poles have flipped places 183 times in the last 83 million years. That’s about every 450,000 years on average, though there were ten million years between flips in at least two cases.

The Earth’s magnetic field is experiencing some rapid changes right now, but scientists say that has no relation to pole flipping.

April 30, 2022April 30, 2022 by Nancy Atkinson

Antarctica Lost an Ice Shelf, but Gained an Island

The eastern coast of Antarctica has lost most of the Glenzer and Conger ice shelves, as seen in these satellite images taken between November 15, 1989 - January 9, 2022. Credit: NASA GSFC/UMBC JCET.

Collapsing ice shelves on the eastern coast of Antarctica has revealed something never seen before: a landform that might be an island. But this is not the first newly revealed island off the Antarctic coast. A series of islands have appeared as the ice shelves along the continent’s coastline has disintegrated over the past few years.