Impact Theory Gets Whacked

By -


Source: Daniel Clery, Science  
Excerpt:  Where did the moon come from? For 3 decades, planetary scientists have agreed that ... a body the size of Mars struck Earth a glancing blow that reduced both to rubble. The cloud of debris reformed itself into the modern Earth and moon ..."giant impact" theory neatly explained why the rocks Apollo astronauts brought back from the moon closely resembled rocks on Earth—or so it seemed at first. ...recent computer models show, such a collision wouldn't have scrambled the two bodies together enough to explain the similarity. Meeting last month in London to discuss the problem, scientists agreed that the origin of the moon must have been messier and more complicated than anyone had assumed.... [Hear podcast interview at http://www.sciencemag.org/content/342/6155/183/suppl/DC1]

http://www.sciencemag.org/content/342/6155/183

Popular posts from this blog

Supernova of a Generation: Brightest Exploding Star in 40 Years Spotted

By -
Source:   IB Times Excerpt: Astronomers from Berkeley have discovered the closest supernova, or exploded star, in 40 years in the Pinwheel Galaxy, located just 21 million light-years from Earth. ...Being the source of most of the chemical elements in the universe heavier than iron, supernovas also play an important role in the evolution of galaxies and planetary systems. They also seed the rest of space with elements such as carbon, oxygen and nitrogen, and can "nudge" gas clouds into collapsing to form new star systems. www.ibtimes.com/art/services/print.php
Read more

How an Ocean-Sized Lake May Have Formed on Ancient Mars

By -
By Saima May Sidik , Eos/AGU.  Excerpt: Geological evidence on Mars indicates that 3.6 billion years ago, an intense pulse of water carved rivers and lakes across the planet, an abrupt shift from the preceding 500-million-year era of much gentler fluvial activity. Researchers have long  puzzled over  the cause. A new study by  Buhler  shows, paradoxically, that the collapse of the Martian atmosphere and entry into a  colder  climate may have melted the polar ice cap and triggered global-scale flooding. ...In total, about 4% to 40% of the water ice could have melted, an amount of water equivalent to between 20% and 200% of the  water currently found near the surface on Mars ....  Full article at https://eos.org/research-spotlights/how-an-ocean-sized-lake-may-have-formed-on-ancient-mars . 
Read more

Young double-star system discovered near our Galaxy’s giant black hole

By -
By Daniel Clery , Science.  Excerpt: Astronomers studying the murky center of our Milky Way Galaxy have discovered something they never expected:  a pair of young stars orbiting each other near the supermassive black hole that is our Galaxy’s dark heart . The observation—reported today in Nature Communications—comes as a surprise because astrophysicists had thought the black hole’s intense gravity would either rip the stars in such a pair apart or squash them together. But the new object, dubbed D9, shows that such a “binary” can survive, at least briefly, near the black hole, and it could help explain other mysterious objects in the vicinity. ...For many years, two teams, in California and Germany, monitored the  closest of those stars . About 20 years ago, both proved the star’s eccentric, high-speed orbit could only arise if it was circling a compact object with extreme mass—a black hole. For that work, the teams’ leaders, Reinhard Genzel of the Max Planck Institu...
Read more