Astro Blog

By DANIEL CLERY , Science.  Excerpt: Astronomers suspect an unusual near-Earth rocky object is not a typical escapee from the Solar System’s asteroid belt, but is instead a chunk of the Moon blasted into space eons ago by a spectacular impact. Now, a team of researchers has modeled what sort of lunar impact could have ejected such a gobbet of Moon and deposit it in a stable, nearby orbit. Surprisingly, only one strong candidate emerged: the asteroid strike that created the famous Giordano Bruno crater, the youngest large crater on the Moon, the  group reports today  in Nature Astronomy. ...The odd asteroid, known as 469219 Kamo‘oalewa, was discovered in 2016 ...measures between 40 and 100 meters across and rotates particularly fast—once every 28 minutes. It follows an elliptical orbit around the Sun that moves in sync with Earth, giving the impression that the asteroid orbits Earth, even though it is outside the planet’s gravitational influence. The asteroid’s curious orbit and small s

By PAUL VOOSEN , Science.  Excerpt: In its youth, the Solar System underwent a momentous upheaval: Gravitational tugs between the giant planets threw them off track, causing Jupiter’s orbit to jump closer to the Sun, while Saturn, Uranus, and Neptune were flung outward. The gravity of the rampaging giants scattered Pluto and other icy bodies to the Kuiper belt, shepherded the asteroid belt into its current location, and sent countless bodies crashing into the inner Solar System. For many years, researchers believed this “giant planet instability” occurred 600 million years after the Solar System’s birth 4.57 billion years ago, based on the ages of impact craters mapped on the Moon. Recently, evidence has mounted that it  occurred much earlier . And now, some researchers are homing in on a more precise date, just 60 million years after the Solar System’s formation, based on an analysis of rare meteorites derived from an ancient asteroid family, published today in Science. Other recent w

https://eos.org/articles/tatooine-trisolaris-thessia-sci-fi-exoplanets-reflect-real-life-discoveries By Kimberly M. S. Cartier , Eos/AGU.  Excerpt: Astronomers have discovered more than 5,000 extrasolar planets since the 1995 discovery of 51 Pegasi b. When the discoveries  started pouring in , astronomers quickly realized that few exoplanets resembled  anything in the solar system . ...A new study led by Puranen examined how the discovery of real exoplanets has influenced portrayals of fictional ones. The researchers showed that as scientists discovered that real-life exoplanets rarely resembled Earth, sci-fi exoplanets became less Earth-like, too. ...The analysis showed that “fictional exoplanets from after the real-life discovery of exoplanets were less likely to have intelligent native life and less likely to have established populations of non-native humans,” Puranen said. Sci-fi exoplanets became less Earth-like and more likely to feature nonintelligent native biospheres. These re