Evidence Against Moon as Meteoroid’s Offspring

By -


Source:  Sindyan N. Bhanoo, The New York Times
Excerpt: Astronomers have long theorized that the Moon was formed when an object the size of Mars slammed into Earth, sending a huge mass of rock into orbit around it. “According to the prevailing model prediction, approximately half of the Moon-forming material should come from the Mars-size impactor,” said Junjun Zhang, an isotope geochemist at the University of Chicago and the study’s first author. But samples of isotopic titanium from the Moon and from Earth now suggest that material from Earth is predominant on the Moon, researchers report in the journal Nature Geoscience. …She and her colleagues used lunar samples gathered by the Apollo missions in the 1960s and ’70s. They compared the isotopic titanium ratio in these samples to that of samples from Earth. The researchers also found that meteorites have a much wider range of isotopic titanium. “That also tells us that the impactor that hit the Earth was very unlikely to have to the same composition as the Earth,” Ms. Zhang said. “So the prevailing model of the giant impact probably needs to be revisited.”…. 

 http://www.nytimes.com/2012/04/03/science/new-insight-on-moons-origins.html

Popular posts from this blog

Stellar remains of famed 1987 supernova found at last

By -
https://www.science.org/content/article/stellar-remains-famed-1987-supernova-found-last By DANIEL CLERY , Science.  Excerpt: When a nearby star exploded in 1987, it created the first supernova visible to the naked eye in 4 centuries and became one of the most intensely studied objects in space. Now, after more than 35 years of searching, researchers have finally discovered the cinder left behind. Using NASA’s new giant space telescope JWST, astronomers spotted  glowing gas at the center of the blast that can only have been energized by something hot and compact inside it , they report this week in Science. They believe a neutron star, all that remains of the shattered star, is responsible.... 
Read more

Planets around dead stars offer glimpse of the Solar System’s future—after the Sun swallows us up

By -
https://www.science.org/content/article/planets-around-dead-stars-offer-glimpse-solar-system-s-future-after-sun-swallows-us By JONATHAN O’CALLAGHAN , Science.  Excerpt: In about 5 billion years the Sun will balloon up into a red giant, consuming Mercury, probably Venus, and maybe even Earth. But even if the outer planets avoid being swallowed up, they might eventually get pulled in or ejected from the Solar System. A new discovery suggests they can survive intact. Using NASA’s JWST space telescope, astronomers have for the first time directly imaged planets on Solar System–like orbits around white dwarfs, the dead stars left after Sun-like stars swell into red giants and subside. The planets follow orbits resembling those of the giant planets in the outer Solar System—big enough for them to have escaped the inferno.... For GSS A Changing Cosmos chapter 1.
Read more

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