Space and astronomy news
Can a star have a solid surface? It might sound counterintuitive. But human intuition is a response to our evolution on Earth, where up is up, down is down, and there are three states of matter. Intuition fails when it confronts the cosmos.
Continue reading “New Observations Confirm That a Magnetar has a Solid Surface and No Atmosphere”
650 million years ago, Earth was completely or almost completely frozen, according to the Snowball Earth Hypothesis. As the atmosphere changed and Earth warmed up, it heralded the beginning of the Ediacaran Period. The Ediacaran Period marks the first time multicellular life was widespread on the planet. It predates the more well-known Cambrian Period, when more complex life emerged, diversified, and flourished.
Life during the Ediacaran Period faced a mass extinction, and it was Earth’s first one.
What happened?
Continue reading “Earth’s First Known Mass Extinction Event Starved Life of Oxygen”
Sometimes it’s tempting to imagine a supernatural hand behind the arrangement of celestial bodies. But the Universe is big, huge even, and nature’s flow presents many fascinations.
So it is with the galactic triplet Arp 248, an arrangement of interacting galaxies that’s both visually and scientifically fascinating.
Continue reading “The Perfect Tidal Tail Connects These two Galaxies Seen by Hubble”
Researchers using the IceCube Neutrino Observatory have detected neutrinos emanating from the energetic core of an active galaxy millions of light-years away. Neutrinos are difficult to detect, and finding them originating from the galaxy is a significant development. What does the discovery mean?
Continue reading “IceCube Senses Neutrinos Streaming From an Active Galaxy 47 Million Light-Years Away”
An asteroid 1.5 km across is no joke. Even a much smaller one, about the size of a house, can explode with more power than the first nuclear weapons. When an asteroid is greater than 1 km in diameter, astronomers call them “planet-killers.” The impact energy released from a planet-killer striking Earth would be devastating, so knowing where these asteroids are and where they’re headed is critically important.
Our defensive capability against asteroid strikes is in its infancy, so advance notice of asteroids that could cross Earth’s orbit is critical. We’ll need time to prepare.
Continue reading “Three New Potentially Hazardous Asteroids Discovered, Including a big one That Measures 1.5 km Across”
Scientists have long suspected that Mars was once warm and wet in its ancient past. The Mars Ocean Hypothesis says that the planet was home to a large ocean around 4 billion years ago. The ocean filled the Vastitas Borealis basin in the planet’s northern hemisphere. The basin is 4–5 km (2.5–3 miles) below Mars’ mean elevation.
A new topographic map of Mars reinforces the hypothesis and adds more detail.
Continue reading “Scientists Piece Together the Shoreline of an Ancient Ocean on Mars”
Edward Stone is retiring after 50 years as Project Scientist for the Voyager mission. The twin spacecraft revolutionized our understanding of our Solar System, and Stone was along for the ride every step of the way. Both spacecraft are still going, travelling deeper into interplanetary space, and still sending data home.
But after a long and rewarding career full of achievements and recognition, Stone is moving on.
Continue reading “Edward Stone Has Been the Voyagers’ Project Scientist for 50 Years. He Just Retired”
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.
Continue reading “The Most Devastating Solar Storms in History are Scoured Into Tree Rings”
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.
Continue reading “Earth’s Hardiest Bacteria Could Survive Hundreds of Millions of Years Just Under the Surface of Mars”
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.
Continue reading “How Dangerous are Nearby Supernovae to Life on Earth?”