Earth Archives - Universe Today

November 19, 2020November 19, 2020

There Might Be Water On All Rocky Planets

Artist’s impression of a massive asteroid belt in orbit around a star. Earth's water may not have all come from asteroids and comets, so maybe that's true for exoplanets. Credit: NASA-JPL / Caltech / T. Pyle (SSC)

If you asked someone who was reasonably scientifically literate how Earth got its water, they’d likely tell you it came from asteroids—or maybe comets and planetesimals, too—that crashed into our planet in its early days. There’s detail, nuance, and uncertainty around that idea, but it’s widely believed to be the most likely reason that Earth has so much water.

But a new explanation for Earth’s water is emerging. It says that the water comes along for the ride when Earth formed out of the solar nebula.

If that’s correct, it means that most rocky planets might have water for at least a portion of their lives.

November 18, 2020November 18, 2020

An Iceberg the Size of South Georgia Island is on a Collision Course with… South Georgia Island

Back in July 2017, satellites watched as an enormous iceberg broke free from Antarctica’s Larsen C ice shelf on the Antarctic Peninsula. The trillion-ton behemoth has been drifting for over three years now. While it stayed close to its parent ice shelf for the first couple of years, it’s now heading directly for a collision with South Georgia Island.

It could be a slow-motion collision, but a collision nonetheless. If it does collide with the island and its shallow sea-floor, it won’t be the first iceberg to do so. And if the first one was any indication, wildlife could suffer.

November 18, 2020November 18, 2020

There’s a Vast Microbial Ecosystem Underneath the Crater that Wiped Out the Dinosaurs

How did life arise on Earth? How did it survive the Hadean eon, a time when repeated massive impacts excavated craters thousands of kilometres in diameter into the Earth’s surface? Those impacts turned the Earth into a hellish place, where the oceans turned to steam, and the atmosphere was filled with rock vapour. How could any living thing have survived?

Ironically, those same devastating impacts may have created a vast subterranean haven for Earth’s early life. Down amongst all those chambers and pathways, pumped full of mineral-rich water, primitive life found the shelter and the energy needed to keep life on Earth going. And the evidence comes from the most well-known extinction event on Earth: the Chicxulub impact event.

October 27, 2020October 27, 2020

Scientists in Japan Have Found a Detailed Record of the Earth’s Last Magnetic Reversal, 773,000 Years Ago

Every 200,000 to 300,000 years Earth’s magnetic poles reverse. What was once the north pole becomes the south, and vice versa. It’s a time of invisible upheaval.

The last reversal was unusual because it was so long ago. For some reason, the poles have remained oriented the way they are now for about three-quarters of a million years. A new study has revealed some of the detail of that reversal.

October 23, 2020October 23, 2020

Geologists Have Found the Earth’s Missing Tectonic Plate

Northern Canada has been keeping a secret from the rest of the world. It’s home to “Resurrection,” a tectonic plate that has been much theorized but never found until now. A team of researchers used what amounts to a CAT scan of northern Canada and the mantle underneath it to find the missing plate.

Finding it could lead to better hazard prediction and also to finding mineral and hydrocarbon deposits. But better than that, it’s helping scientists piece together Earth’s history.

October 22, 2020October 22, 2020

Scientists Think They Know What Caused the Deadliest Mass Extinction in the History of the Earth

This illustration shows the percentage of marine animals that went extinct during Earth's worst extinction at the end of the Permian era by latitude, from the model (black line) and from the fossil record (blue dots).A greater percentage of marine animals survived in the tropics than at the poles. The color of the water shows the temperature change, with red being most severe warming and yellow less warming. At the top is the supercontinent Pangaea, with massive volcanic eruptions emitting carbon dioxide. The images below the line represent some of the 96 percent of marine species that died during the event. [Includes fossil drawings by Ernst Haeckel/Wikimedia; Blue crab photo by Wendy Kaveney/Flickr; Atlantic cod photo by Hans-Petter Fjeld/Wikimedia; Chambered nautilus photo by John White/CalPhotos.]Justin Penn and Curtis Deutsch/University of Washington

Humanity can have a love/hate relationship with itself, but there’s no denying that we’re the pinnacle of evolution on Earth as things stand now. But it took an awfully long time for evolution to produce beings such as we. Several times, life had to drag itself back from near annihilation.

The largest extinction setback was the Permian-Triassic extinction, also called the “Great Dying,” some 252 million years ago. Up to 96% of all marine species and 70% of terrestrial vertebrate species went extinct.

What happened?

October 17, 2020October 17, 2020

Great Barrier Reef Has Lost Half of its Coral Over the Last 25 Years

Great Barrier Reef, Queensland, Australia August 1992

A new study found that warmer ocean temperatures driven by climate change have caused Australia’s Great Barrier Reef to lose more than half of its corals since 1995. The researchers say virtually all coral populations along the Great Barrier Reef have declined due to repeated “bleaching events” in the past 25 years. They said the devastation of the coral will continue unless action is taken to mitigate the causes of a warming climate.

October 2, 2020October 2, 2020

A Supernova Exploded Dangerously Close to Earth 2.5 Million Years Ago

In its 4.5 billion year history, Earth has had to run the gauntlet. Numerous catastrophes have imperilled the planet, from massive impacts, to volcanic conflagrations, to frigid episodes of snowball Earth. Yet life persists.

Among all of the hazards that threaten a planet, the most potentially calamitous might be a nearby star exploding as a supernova.

September 24, 2020September 24, 2020

A New Mass Extinction has been Discovered, Wiping Out Life 233 Million Years Ago, and Leading to the Rise of the Dinosaurs

Most everybody knows that the dinosaurs perished rapidly in a tumultuous extinction, caused by an asteroid strike about 66 million years ago. But it looks like another extinction prior to the appearance of the dinosaurs paved the way for their long reign. That extinction took place about 233 million years ago.

And scientists have only now discovered it.

September 22, 2020September 22, 2020

This is the View You Get Staring out of the Space Station’s Cupola Module

Those lucky few who have the incredible opportunity to see the Earth from space often report the view gives them a sense of awe, unity and clarity. This perspective-altering experience has come to be known as the Overview Effect, from a book by the same name published 1987 by space philosopher Frank White.