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Strange New 'Twin' Worlds Found
toomanyairmiles writes "The BBC reports on the the discovery of 'twin worlds' which orbit each other, successfully blurring the line between planets and stars. 'Their existence challenges current theories about the formation of planets and stars.' according to the Journal of Science article which reports their existence. 'The pair belongs to what some astronomers believe is a new class of planet-like objects floating through space; so-called planetary mass objects, or "planemos", which are not bound to stars.'"
It's a space station!
A slashdotter who didn't build his own computer is like a Jedi who didn't build his own lightsaber.
Stars can only 'ignite' when enough mass accumulates. It would make sense that often there would be chunks of smaller mass just floating around until they scoop up enough matter into their gravity well to start fusion.
Anticipating a possible question: no, a previously-unknown population of "planemos" can't be the dark matter astronomers are searching for. First, there were enough of them to account for the huge mass of dark matter (some 95 percent of the mass of the universe), we would have seen a lot more of them by now. "Massive compact halo objects", or basically planetoids, brown dwarfs, neutron stars, etc. have been detected (via gravitational lensing), but they are known not to comprise the majority of dark matter due to such bounds on their total mass. Furthermore, from the effects of dark matter on structure formation in the early universe, the cosmic background radiation, and other factors, it is known that "normal" matter can't account for most of the mass of dark matter, either: most of it needs to be in the form of "weakly interactive massive particles" (sort of analogous to neutrinos, except much heavier).
No folly is more costly than the folly of intolerant idealism. - Winston Churchill
"The pair belongs to what some astronomers believe is a new class of planet-like objects floating through space; so-called planetary mass objects, or "planemos", which are not bound to stars.'"
Once again proving that astronomers should not be naming things while drunk. Here's a handy reminder: "Remember the Planemos!"
Vincent J. Murphy
Spandex Justice
I think we can just stick to "The twins"...
I like Planemo and Planelarry, implying, of course, the future discovery of Planecurly and a receding Planeshemp.
KFG
"Yes, it's really easy to confuse a ball of rock with a star. I mean, the similarities are so obvious."
In terms of such stars as Ben Affleck, the similarities do start to build up.
Where were you when the voynix came?
Which one is the evil twin?
Thank you , I'll be here all evening!
how long until
Snakes, on a PLANEMO????
Where were you when the voynix came?
technically they do... a planetary object by definition needs something to orbit.
What i think you meen is that a nebula of the right size can form a stelar object that doesnt have the mass for fusion.
pluto is thought to be a captured kuiper belt object,, meaning that some collision or gravitational interaction with a massive body brought it in towards the inner solar system, which explains its eccentric orbit which is also at a very high inclination to the plane of the ecliptic.
You are incorrect as to why the planets are on the same elliptical plane.
http://www.nineplanets.org/origin.html
#3 on that page is the step which explains why the solar system is on the same plane. Pluto being outside that plane is most likely it is actually a kupier belt object and was far enough out from the formation of our sun to not have fully fallen into the accretion disc.
More information is available at http://en.wikipedia.org/wiki/Accretion_disc
http://en.wikipedia.org/wiki/Protoplanetary_disc
The reason your explanation doesn't work for why the planetary bodies are on the same plane is because they are all in stable orbits. To plane out into a disc they would need to still be falling towards the sun.
Planetary rings are in the ring pattern because they follow the orbit of the object from which they were created, they are not collected and built up from smaller particles but probably the result of the destruction of a large object.
http://en.wikipedia.org/wiki/Planetary_rings
They both orbit around their common center of mass, as do all pairs of orbiting bodies. The moon and earth actually orbit around a point 4700km from the earths center.
"Prefiero morir de pie que vivir siempre arrodillado!"
Hurm... well, yes and no. Theory gives us an excellent start in almost all areas, but theory is only (as a maximum) as valuable as the data on which it is based. We have very little data about the composition of our galaxy (less, even, than we do about the earth, millions of years ago), so it is not shocking that we would find major gaps in our understanding (we only just recently discovered the supermassive black hole at the center of our galaxy (and most or all others).
First off, that's a non-sequitor. Second, "random" isn't the word you want there. When you are talking about large-scale processes, you can use ranomness as a tool to understand, but as we probe the nature of the universe we have consistently found that things that appear to have no order, are in fact very ordered. When you see two planetary objects orbiting one another, that's not random, it's the result of the gravitational forces exerted by those two bodies and, to increasingly lesser degrees, everything else in the universe. If it appears random, that's just becuase you had too little information about the forces involved.