Earth's Moon a rare species
Moons like the Earth's - which are formed in catastrophic collisions - are extremely rare in the universe, a study by U.S. astronomers suggests.
Cosmic collisions: Artist's impression of bodies as big as mountain ranges smashing together. Such collisions form the basis of the planet-building process. An even bigger collision between Earth and a body the size of Mars is thought to have created our moon. Image: NASA/JPL/Caltech
Billions of years ago, an object the size of Mars crashed into the Earth, hurling dust and debris into orbit. Some of this material eventually coalesced to form our Moon.
Now a new study in The Astrophysical Journal reports that only five to 10 per cent of planetary systems in the universe have moons created this way.
"When a moon forms from a violent collision, dust should be blasted everywhere," said lead author Nadya Gorlova of the University of Florida, Gainesville. "If there were lots of moons forming, we would have seen dust around lots of stars - but we didn't."
A trail of dust
Using NASA's Spitzer Space Telescope, Gorlova and colleagues looked for the dusty signs of similar collisions. They examined 400 stars that are all about 30 million years old - roughly the age of our Sun when Earth's moon formed.
They found only one out of the 400 stars immersed in the telltale dust. Taking into account the amount of time the dust should stick around, and the age range at which moon-forming collisions can occur, the researchers calculated the probability of a solar system making a moon like Earth's to be at most five to 10 per cent.
Rocky planet window
Like our moon, rocky planets are built up through messy collisions that scatter dust and debris around. Current thinking holds that this process lasts from about 10 to 50 million years after a star forms.
But the fact that Gorlova and her team found only one star out of 400 with collision-generated dust, suggests that the 30-million-year-old stars in the study have, for the most part, finished making their planets.
"We don't know that the collision we witnessed around the one star is definitely going to produce a moon, so moon-forming events could be much less frequent than our calculation suggests," said George Rieke of the University of Arizona, Tucson, a co-author of the study.
But for moon lovers, the news isn't all bad. For one thing, moons can form in different ways: the other moons in our solar system either formed simultaneously with their planet or were captured by their planet's gravity.
And even though the majority of rocky planets in the universe might not have moons like Earth's, there are billions of rocky planets out there, so five to 10 percent is a lot of moons.
Article from: http://www.cosmosmagazine.com/node/1720
Our Enigmatic Moon
Were we on the Moon in 2309 B.C.?
The Moon - What Is It And Who Made It?
Mysterious Moonbase Message
Red Ice Creations Radio - Ted Twietmeyer - What NASA isn't Telling you about Mars
Red Ice Creations Radio - Ted Twietmeyer - The Moon & Sun, Time & UFO's (Subscription)
'Lunar Ark' Proposed in Case of Deadly Impact on Earth
Red Ice Creations Radio - Joseph P Farrell - Cosmic War, Interplanetary Warfare & Mesopotamian Mythology
Red Ice Creations Radio - Joseph P Farrell - Interplanetary Warfare, Mythology & Nazi Occultism (Subscription)
Red Ice Creations Radio - Michael Tsarion - Lucifer & The Dark Side of the Sun
Ancient Moon 'computer' revisited
Velikovsky's Ghost Returns
Giant impact added to Earth's core
Latest News from our Front Page
An Occupied Country
When people refer to occupation governments or occupied countries, the first thought is often of military occupation—the garrisoning of foreign troops in one’s cities and civil administration by their military executives. The other vision is the trope of a cabal of Haredim sitting in a darkly-lit boardroom with a map of the world on the wall, a dated reading of ...
Immortal Symbols 1941
Youtube description: Dutch film "Eeuwig Leevende Tekens" by Hamer - "Volksche Werkgemeenschap" (Folkish Study Group) - ancestral heritage, solar wheel, sun cross, tree of life, etc.
Subs by Otharus - http://fryskednis.blogspot.com
Ex-German media boss admits on live radio the national news agenda is govt controlled
f you really want a lesson in how the Western popular press works, this is it.
Without question, Germany is the leading power in Europe. ZDF is its state broadcaster and most popular channel.
Together with sister network ARD; German's are obliged to pay €17.98 per month to fund it.
This week, during a radio event in Berlin, the retired head of ZDF ...
British teenager is gang raped by 'Moroccan' men after being dragged into a car in Spain
A British teenager claims to have been gang-raped in a Spanish resort after being dragged into a car by a group of Moroccan men, it was reported today.
The 18-year-old claimed she was attacked while walking home from work late at night in Sabinillas, near Marbella.
Police are said to be investigating a group of Moroccan men in the area.
A British teenager ...
8 Ways Racially Diverse Schools Hurt White Kids
Description from YouTube:
I argue against Mother Jones Propaganda
Link to the original Mother Jones Article: 3 Ways White Kids Benefit Most From Racially Diverse Schools
Links to all the articles and other citations mentioned in my video can be found here: docdro.id/6CpKvgA
|More News » |