Milky Way is much faster, heavier and accident prone

The Milky Way—our home galaxy—is rotating at a much faster rate, is much heavier and has a much higher likelihood of colliding with neighbouring galaxies than previously estimated, new findings presented on Monday suggest.

Astronomers have found that Milky Way—in which our solar system is located—is moving at six lakh miles per hour in the Galactic orbit which is higher by one lakh miles per hour than previously estimated. Scientists at the Harvard-Smithsonian Center for Astrophysics, Massachusetts say that the present speed increased the mass of Milky Way by 50% making it equal to nearby Andromeda Galaxy. “No longer will we think of the Milky Way as the little sister of the Andromeda Galaxy in our Local Group family,” said Mark Reid, one of the researchers. The larger mass, in turn, means a greater gravitational pull that increases the likelihood of collisions with the Andromeda galaxy or smaller nearby galaxies, he said.

“Our Solar System is about 28,000 light-years from the Milky Way’s centre. At that distance, the new observations indicate, we’re moving at about 600,000 miles per hour in our Galactic orbit, up from the previous estimate of 500,000 miles per hour,” Reid said while presenting findings at American Astronomical Society’s meeting in California. The researchers have used Very Long Baseline Array (VLBA) radio telescope to redraw the map of Milky Way. The telescope, known for its ability to make very detailed images of the galaxy, is being used by scientists to measure distances and motions taking place in it.

“The new VLBA observations of the Milky Way are 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. “These measurements use the traditional surveyor’s method of triangulation and do not depend on any assumptions based on other properties, such as brightness, unlike earlier studies.”