Space and astronomy news
Mars’ ancient climate is one of our Solar System’s most perplexing mysteries. The planet was once wet and warm; now it’s dry and cold. Whatever befell the planet, it didn’t happen all at once.
New research shows that on ancient cold Mars, sheets of frozen carbon dioxide allowed rivers to flow and a sea the size of the Mediterranean to exist.
Continue reading “Flowing Martian Water was Protected by Sheets of Carbon Dioxide”
The term ‘habitable zone’ is a broad definition that serves a purpose in our age of exoplanet discovery. But the more we learn about exoplanets, the more we need a more nuanced definition of habitable.
New research shows that vegetation can enlarge the habitable zone on any exoplanets that host plant life.
Continue reading “How Vegetation Could Impact the Climate of Exoplanets”
There’s a link between Earth’s ocean salinity and its climate. Salinity can have a dramatic effect on the climate of any Earth-like planet orbiting a Sun-like star. But what about exoplanets around M-dwarfs?
Continue reading “Ocean Salinity Affects Earth’s Climate. How About on Exoplanets?”
Even though Venus and Earth are so-called sister planets, they’re as different as heaven and hell. Earth is a natural paradise where life has persevered under its azure skies despite multiple mass extinctions. On the other hand, Venus is a blistering planet with clouds of sulphuric acid and atmospheric pressure strong enough to squash a human being.
But the sister thing won’t go away because both worlds are about the same mass and radius and are rocky planets next to one another in the inner Solar System. Why are they so different? What do the differences tell us about our search for life?
Continue reading “What Deadly Venus Can Tell Us About Life on Other Worlds”
We, and all other complex life, require stability to evolve. Planetary conditions needed to be benign and long-lived for creatures like us and our multicellular brethren to appear and to persist. On Earth, chemical cycling provides much of the needed stability.
Chemical cycling between the land, atmosphere, lifeforms, and oceans is enormously complex and difficult to study. Typically, researchers try to isolate one cycle and study it. However, new research is examining Earth’s chemical cycling more holistically to try to understand how the planet has stayed in the ‘sweet spot’ for so long.
Continue reading “Earth’s Long-Term Habitability Relies on Chemical Cycles. How Can We Better Understand Them?”
During the 1970s, inventor/environmentalist James Lovelock and evolutionary biologist Lynn Margulis proposed the Gaia Hypothesis. This theory posits that Earth is a single, self-regulating system where the atmosphere, hydrosphere, all life, and their inorganic surroundings work together to maintain the conditions for life on the planet. This theory was largely inspired by Lovelock’s work with NASA during the 1960s, where the skilled inventor designed instruments for modeling the climate of Mars and other planets in the Solar System.
According to this theory, planets like Earth would slowly grow warmer and their oceans more acidic without a biosphere that regulates temperature and ensures climate stability. While the theory was readily accepted among environmentalists and climatologists, many in the scientific community have remained skeptical since it was proposed. Until now, it has been impossible to test this theory because it involves forces that work on a planetary scale. But in a recent paper, a team of Spanish scientists proposed an experimental system incorporating synthetic biology that could test the theory on a small scale.
Continue reading “Can the Gaia Hypothesis Be Tested in the Lab?”
A recent study published in Nature Geoscience uses supercomputer climate models to examine how a supercontinent, dubbed Pangea Ultima (also called Pangea Proxima), that will form 250 million years from now will result in extreme temperatures, making this new supercontinent uninhabitable for life, specifically mammals. This study was conducted by an international team of researchers led by the University of Bristol and holds the potential to help scientists better understand how Earth’s climate could change in the distant future from natural processes, as opposed to climate change.
Continue reading “In 250 Million Years, a Single Supercontinent will Form, Wiping Out Nearly all Mammals”
The first early humans to use fire had no inkling of what it would lead to.
Fire was one of our first technologies, and humans have been making changes to their environments since the advent of controlled fire hundreds of thousands of years ago. Fast forward to current times, and our modern technological and global civilization is changing the Earth’s entire biosphere. From carbon emissions that acidify the oceans and weaken the shells of marine life to microplastics that find their way into organisms’ bloodstreams, our technology is intersecting, or combining, with the biosphere.
This has spawned a useful word: biotechnosphere.
Continue reading “Could We Find Aliens Terraforming Other Worlds?”
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.
Continue reading “Scientists Have Been Underestimating the Asteroid That Created the Biggest Known Crater on Earth”
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.
Continue reading “Antarctica Lost an Ice Shelf, but Gained an Island”