'Homeless' Planets May Be Common In Our Galaxy 181
sciencehabit writes "Our galaxy could be teeming with 'homeless' planets, wandering the cosmos far from the solar systems of their birth, astronomers have found. In a paper published online today in Nature, the researchers list 10 objects in our galaxy that are very likely to be free-floating planets. What's more, they claim that in our galaxy, free-floaters are probably so populous that they outnumber stars."
Re:Today we have homeless planets... (Score:5, Insightful)
tomorrow we will have homeless moons, rocks, asteroids etc etc etc... and dark matter will be reduced in a big 0.000001%.
Except that they have to account for five times as much as what astronomers can see or infer exists.
Did it ever occur to you that the experts might actually know what they're talking about?
Re:Dark matter? (Score:4, Insightful)
A bunch of planets floating around in space without orbiting a star
Come to think of it, why are we working on the assumption that basically every object in the universe is on fire*? As a personal bet, £5 says that the vast majority of mass in the universe is in solar systems where the central object either wasn't on fire, or has burnt out billions of years ago
* Yeah, AFAIK the official explanation for this assumption is "because that's all we can see", but maths says there must be more - the explanation for the rest always seems to have dark matter being some mysterious meta-mass unlike anything we know about, rather than simply being planets with no nearby light source...
And your PHB says it shouldn't take so long to write programs.
How come everyone around here knows more than the experts? Do you really think astronomers are too dumb to think of all the non-stellar matter in and between the galaxies?
Re:Dark matter? (Score:5, Insightful)
We know about dark matter not through micro-lensing but because of galactic structure. Galaxies rotate. If all the mass there was in any given galaxy was just what we could see, the centrifugal force would tear apart immediately. The only way we can account for sufficient gravitational attraction to keep stars in their orbits around the galactic center is to assume a lot of mass we can't see--dark matter. Most calculations based on stellar orbits consistently come up with figures for dark matter of over 80% of the matter in the universe. There's more than four times as much dark matter as what we can see. And whatever dark matter is, it apparently is diffuse enough that we don't see it micro-lensing anything, and doesn't otherwise interact with light or other EM radiation, because we find no trace of it in the light that reaches earth from all corners of the universe; therefore it *can't* be ordinary matter as we understand it, because any form of ordinary matter in that quantity would produce detectable occlusion of the light sources behind it. So what is it? Answer that question and win a Nobel.