Posted on 12/17/2011 4:48:48 PM PST by SunkenCiv
NASA's Kepler space telescope... has identified 2,326 candidate planets, nearly doubling its haul since February.
But what has puzzled observers and theorists so far is the high proportion of planets -- roughly one-third to one-half -- that are bigger than Earth but smaller than Neptune... Their very existence upsets conventional models of planetary formation and, furthermore, most of them are in tight orbits around their host star, precisely where the modellers say they shouldn't be.
"It poses a challenge," says Douglas Lin, a planet-formation modeller and director of the Kavli Institute for Astronomy and Astrophysics at Peking University in Beijing, China. "You can't just tweak the parameters. You need to think about the physics."
Guided by the example of our own Solar System, with its distinct sets of large and small worlds, early planet-formation models were based on the notion of 'core accretion'. Dust swirling around a star in a protoplanetary disk can aggregate into small planetesimals of rock and ice, which collide and stick together. The inner part of the disk contains too little material for these cores to grow much bigger than Earth. But farther out, they can attain ten Earth masses or more, enough to attract a vast volume of gas and become Jupiter-like.
The detection, starting in 1995, of Jupiter-sized planets with orbits as short as a few Earth days contradicted these models. The theorists revised their models to allow these 'hot Jupiters' to form far from their star and then migrate in.
(Excerpt) Read more at nature.com ...
Yep.
We know for certain He exists in a different realm, affirming our belief in life outside of our physical constraints. Too frightening or too awesome for us, I suppose.
I wonder if our world is just a wimpy “super-earth’. Our study of planetary systems prior systems before the 1990’s was like studying animals, but being confined to one small area. We might be on the short end of the bell curve as far as planetary mass goes. Considering that the planets that are smaller than earth that we have hard evidence for have very thin or no atmospheres.
Sounds like a sampling bias, we can only detect the planet that our systems can see.
As for planetary formation models, we have a dearth of real data to test our theories on. No surprise then that an input of real data shows deficiencies in our models.
“The gravity on such a large planet could be similar to earths. Gravitational attraction is a function of mass and diameter; if the density of the planet is low, a huge planet could have surface gravity similar to our own.”
That’s the premise to Jack Vance’s 1952 classic “Big Planet” sci-fi novel. Great book. But anything Vance does is great.
Freegards
then does He put the Mormons in charge of these other places as they say He does?????????
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.