Spinning top: An artist's impression of the Milky Way showing the approximate position of our Solar System.
Credit: NASA/JPL-Caltech/R. Hurt
WASHINGTON DC: The Milky Way is spinning much faster and has 50 per cent more mass than previously believed, increasing the chance of a collision with another galaxy, say astronomers.
An international team of researchers have used ten telescopes spread out between Hawaii, the Caribbean and the northeastern United States to determine that the Milky Way is rotating at a speed of 161,000 km/h faster than previously thought.
Gravitational pull
That increase in speed boosts the Milky Way's mass by 50 per cent, said Mark Reid, of the Harvard-Smithsonian Centre for Astrophysics, in research presented at the American Astronomical Society meeting this week in Long Beach, California.
"No longer will we think of the Milky Way as the little sister of the Andromeda Galaxy," he said.
The larger mass, however, also means that the galaxy has a greater gravitational pull, which heightens the likelihood of collisions with the Andromeda galaxy or smaller nearby galaxies, Reid said.
The Earth's Solar System is located some 28,000 light years from the centre of the Milky Way. At that distance, the new measurements show that the galaxy is rotating at a speed of 965,600 km/h, compared to previous estimates of 804,672 km/h, the astronomers report.
The new observations from the network of radio telescopes is "producing highly-accurate direct measurements of distances and motions," said Karl Menten of the Max Planck Institute for Radio Astronomy in Germany, a member of the team.
Difficult to determine
"These measurements use the traditional surveyor's method of triangulation and do not depend on any assumptions based on other properties, such as brightness," Menten said. The direct measurements "are revising our understanding of the structure and motions of our Galaxy."
It is difficult to determine the structure of the Milky Way because the Earth is inside it.
"For other galaxies, we can simply look at them and see their structure, but we can't do this to get an overall image of the Milky Way," added Menten. "We have to deduce its structure by measuring and mapping."
Nope??
Look at the galaxy rotation curve at http://en.wikipedia.org/wiki/Galaxy_rotation_curve for more information on how fast a typical spiral galaxy rotates versus distance from the center.
Earle Knowles
how to follow a thread
This thread is brilliant, we have comments be a visitor, replied to by a visitor, then a second reply, by a visitor !!!. Does the second reply relate to the original post or the first reply? Was it posted by the original poster?
I mention this in terms of the One of the wonderful mysteries of Galactic Physics portion of the thread. Does the nope reply relate to the original post of the angular motion reply?
And to muddy the waters am I one of the posters in the aforementioned list???
Galaxy rotation...
(Evolution of the Plasma Universe: I. Double Radio Galaxies, Quasars, and Extragalactic Jets)
http://public.lanl.gov/alp/plasma/downloadsCosmo/Peratt86TPS-I.pdf
(Evolution of the Plasma Universe: II. The Formation of Systems of Galaxies)
http://public.lanl.gov/alp/plasma/downloadsCosmo/Peratt86TPS-II.pdf
See the 2nd part, mostly. First part included for completeness...
Under electrical assumptions, galactic cores (and perhaps a bit further out) can tend to rotate like a *solid body*, rather than as fluid circling the drain.
It's all about the plasma cosmology! If astronomers would take the time to read the literature, they might learn a thing or two. Dark Matter is a galactic-scale fudge factor to balance unbalanced gravity-only equations. Toss in the much stronger electric force, and certain features appear to line up more naturally with observations.
Visitor?
Isn't that the pot calling the kettle black, Visitor? =oP
Run for your lives!
The impending collision with the Andromeda galaxy is sure to be catastrophic! Forget about all the "World is going to end in 2012" BS!!!
....
lets do mass suicide then.
does israel have atomic bombs? i hope not..
Meh. I got my towel. You?
Meh. I got my towel. You?
No worries
Galaxy collision is not a destructive process. Besides, it'll look real cool, if there is anyone around to see it by the time it happens.
Plenty of images of other galaxies in various states of collision out there. Look 'em up. Great for scientific research, and desktop wallpaper.
dark matter
I wonder how this affects estimates of dark matter and dark energy in our galaxy.
Anyway, great article.
Cap and Trade!
The increased mass is likely caused by humans burning fossil fuels (or at least, not paying enough taxes)!
Consensus is in! We need more controls! More taxes! More government regulation!