Mission Complete! WMAP In 'Graveyard Orbit'

astroengine writes "The Wilkinson Microwave Anisotropy Probe (WMAP) has, quite literally, changed our view of the Universe. And after nine years of mapping the slight temperature variations in the cosmic microwave background (CMB) radiation, its job is done and NASA has commanded the probe to fire itself into a 'graveyard orbit' around the sun. WMAP measured the most precise age of the universe (13.75 billion years), discovered more evidence supporting dark energy and dark matter theories, and found one or two mysteries along the way."

Comments

Uuhhh... clumsy PR?

[oldhack]

That project was supposed to go on for a few more months I thought... The cooling system exhausted prematurely, didn't it?

Re:Uuhhh... clumsy PR?

[Afforess]

No, according to wikipedia the project was actually extended an extra year to 2010. So it went above and beyond it's original mission.

Dark Matter (Gravity); please explain

[grangerg]

So Dark Matter was a theory invented to explain why stars orbit a galaxy's core like they were on spokes around the hub of a wheel ...instead of how we observe the motion of object orbiting our sun. So if Dark Matter exerts such a huge force to keep huge objects (stars) moving in such a manner, how come that same force doesn't affect the objects going around the star? Or, in other words, if it's powerful enough to keep the outer-most stars in a galaxy moving in the same period as inner stars, how come we can't detect it here? Or have we detected such tidal forces already?

Re:Dark Matter (Gravity); please explain

[ETEQ]

I guess no one knows such things, but I wonder what would prevent it from clumping up like normal baryonic matter. Maybe it's too diffuse to form dark matter nebulae, but those are only held together by gravity too, right? Or would fast-moving particles just fly apart before gravity could act? Or maybe we just can't see the clumps. Or maybe it's a happy medium—loosely bound to the galaxy but nothing more...

Actually, the explanation for this one is pretty simple: it's because the dark matter is dark. The reason why baryonic matter collapses into a (relatively) tiny disk in the center of a much larger dark matter halo is that baryonic matter emits light... and light carries off energy. So baryonic matter quickly loses all the energy it can while still conserving angular momentum, and the result is a disk-like structure (spiral galaxies). Once it collapses into a disk, the density becomes high enough that it can further clump into nebulae and stars and such. Dark matter, on the other hand, is much lower density and hence isn't able to collapse efficiently (i.e. its Jean's Length is much longer, if you want to think in terms of some simple math).

Cosmic background radiation

[BadAnalogyGuy]

What if the cosmic background "warmth" which hovers just above 2 Kelvin isn't the remnants of the Big Bang but rather a physical phenomenon produced by some more general aspect of our universe. Like goldfish in a bowl, the limits of our experience are defined by our universe, so the phenomena we experience define and are defined within that framework. But like a human outside the goldfish bowl, we can understand why certain phenomena (such as bending of light through the glass) occurs at a simpler, more general level than the goldfish within could grasp.

Our bowl tells us that there is a background radiation permeating the universe, that unknown and unobservable matter and energy are pulling the universe this way and that, and that time and space exist. We send our tools out to study and measure this bowl. We come away with a great deal of understanding of our bowl, but for some reason things don't all fit together.

Outside this bowl of ours there is probably a simple and elegant description of the phenomena we experience here. But for the time being, I'm glad to see us working so hard to learn about this little bowl we live in.

So long.....

[tpstigers]

..... and thanks.

"Mission Accomplified"

[Tablizer]

Ever since Bush, people say mission "complete" instead of "accomplished". Then again, the word "stimulus" is tainted also, replaced with "recovery program".