Space and astronomy news
Our CO2 emissions are warming the planet and making life uncomfortable and even unbearable in some regions. In July, the planet set consecutive records for the hottest day.
NASA is mapping our emissions, and while what they show us isn’t uplifting, it is visually appealing in a ghoulish way. Maybe the combination of visual appeal and ghoulishness will build momentum in the fight against climate change.
Continue reading “Our Carbon Dioxide Emissions Have a Mesmerizing Side”
Next time you’re visiting the seaside or a large lake, or even sipping a frosty glass of water, think about where it all originated. There are many pathways that water could have taken to the infant Earth: via comets, “wet asteroids”, and outgassing from early volcanism. Aster Taylor, a University of Michigan graduate student has another idea: dark comets. They’re something of a cross between asteroids and comets and could have played a role in water delivery to our planet.
Continue reading “More Than Half of Near Earth Objects Could Be “Dark Comets””
Earth’s protective atmosphere has sheltered life for billions of years, creating a haven where evolution produced complex lifeforms like us. The ozone layer plays a critical role in shielding the biosphere from deadly UV radiation. It blocks 99% of the Sun’s powerful UV output. Earth’s magnetosphere also shelters us.
But the Sun is relatively tame. How effective are the ozone and the magnetosphere at protecting us from powerful supernova explosions?
Continue reading “Earth’s Atmosphere is Our Best Defence Against Nearby Supernovae”
Scientists scour the Earth and the sky for clues to our planet’s climate history. Powerful and sustained volcanic eruptions can alter the climate for long periods of time, and the Sun’s output can shift Earth’s climate over millions of years.
But what about interstellar hydrogen clouds? Can these regions of gas and dust change Earth’s climate when the planet encounters them?
Continue reading “Was Earth’s Climate Affected by Interstellar Clouds?”
Earth is naked without its protective barrier. The planet’s magnetic shield surrounds Earth and shelters it from the natural onslaught of cosmic rays. But sometimes, the shield weakens and wavers, allowing cosmic rays to strike the atmosphere, creating a shower of particles that scientists think could wreak havoc on the biosphere.
This has happened many times in our planet’s history, including 41,000 years ago in an event called the Laschamps excursion.
Continue reading “41,000 Years Ago Earth’s Shield Went Down”
Earth is the only life-supporting planet we know of, so it’s tempting to use it as a standard in the search for life elsewhere. But the modern Earth can’t serve as a basis for evaluating exoplanets and their potential to support life. Earth’s atmosphere has changed radically over its 4.5 billion years.
A better way is to determine what biomarkers were present in Earth’s atmosphere at different stages in its evolution and judge other planets on that basis.
Continue reading “What Can Early Earth Teach Us About the Search for Life?”
We go about our daily lives sheltered under an invisible magnetic field generated deep inside Earth. It forms the magnetosphere, a region dominated by the magnetic field. Without that planetary protection shield, we’d experience harmful cosmic radiation and charged particles from the Sun.
Continue reading “Earth Had a Magnetosphere 3.7 Billion Years Ago”
Scientists have been underutilizing a key resource we can use to help us understand Earth: animals. Our fellow Earthlings have a much different, and usually much more direct, relationship with the Earth. They move around the planet in ways and to places we don’t.
What can their movements tell us?
Continue reading “How Animal Movements Help Us Study the Planet”
We are all too familiar of the Moon’s effect on our planet. It’s relentless tug causes our tides but even Mars, which is always at least 55 million kilometres away, can have a subtle effect too. A study has revealed a 2.4 million year cycle in the geological records that show the gentle warming and cooling of our oceans. The records match the interactions between the orbits of Earth and Mars over the longest timescales. These are known as the ‘astronomical grand cycles’ but to date, not much evidence has been found.
Continue reading “Gravity From Mars has an Effect on Earth’s Oceans”
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?”