科学与环境
Our sun's undiscovered stellar nemesis is still out there, says physicist
来源: Phys.org - latest science and technology news stories · 发布于
Long-period, high-inclination comets of the sort that can cause extinction-level impacts here on Earth have long been thought to originate from a theoretical Oort cloud. That is, a roughly spherical cloud of icy cometary objects that number in the trillions at distances that exte
Long-period, high-inclination comets of the sort that can cause extinction-level impacts here on Earth have long been thought to originate from a theoretical Oort cloud. That is, a roughly spherical cloud of icy cometary objects that number in the trillions at distances that extend up to 1.6 light-years away.
相关报道
Long-lived mineral grains can be invaluable for reconstructing impact events, but the stories are complex
Reconstructing impact events on Earth and other planetary bodies, including the moon, is crucial for understanding how the solar system evolved and how planets develop.
Phys.org - latest science and technology news stories ·
How the Southern Ocean helped fuel Earth's warmest climate in 65 million years
About 50 million years ago, Earth experienced its warmest climate since the extinction of the dinosaurs. Global temperatures were more than 10°C higher than today, and atmospheric CO₂ concentrations reached around 1,600 parts per million. But what kept CO₂ levels so extraordinari
Phys.org - latest science and technology news stories ·
Two nearby rocky worlds could offer alien astronomers views of planets appearing to reverse course
Aliens have long been a staple of science fiction. Yet the possibility of intelligent life beyond Earth is more than a matter of imagination—it is also a subject of serious scientific inquiry. Professor Woong-bae Zee of Sejong University's School of Liberal Studies has recently p
Phys.org - latest science and technology news stories ·
A nuclear blast could save Earth from an asteroid, but there's a catch
A nuclear explosion might save Earth from a deadly asteroid, but new research suggests that hitting the wrong side could make the difference between success and disaster. Scientists found that an asteroid's irregular shape can dramatically affect how it responds to an X-ray blast
All Top News -- ScienceDaily ·
NASA’s Swift telescope falls to Earth after nearly 22 years in space
After nearly 22 years of exploring the universe’s most violent explosions, NASA’s Swift Observatory has re-entered Earth’s atmosphere over Indonesia. Originally designed to last just two years, the pioneering space telescope transformed our understanding of black holes, exploding
All Top News -- ScienceDaily ·