BEIJING, Aug. 7 (Xinhuanet) -- Four galaxies at least the size of the Milky Way comprised of billions of stars are on a collision course that when consumated will create a single, colossal galaxy up to 10 times as massive as our own, scientists say.

    "When this merger is complete, this will be one of the biggest galaxies in the universe," said study team member Kenneth Rines of the Harvard-Smithsonian Center for Astrophysics.

    The finding, to be detailed in an upcoming issue of Astrophysical Journal Letters, gives scientists their first real peek into a galaxy merger involving multiple big galaxies.

    "Most of the galaxy mergers we already knew about are like compact cars crashing together," Rines said. "What we have here is like four sand trucks smashing together, flinging sand everywhere."

    Galaxy collisions are a common occurrence in the universe. The Milky Way will collide and merge with its neighbor, Andromeda, in about 5 billion years.

    NASA's infrared Spitzer Space Telescope located the quadruple merger during a routine survey of a distant galaxy cluster named CL0958+4702 about 5 billion light years away. Spitzer observed an unusually large fan-shaped plume of light emerging from a gathering of four blob-shaped elliptical galaxies.

    The plume turned out to be billions of elderly stars ejected and abandoned during the clash. About half of the stars in the plume will later fall back into the galaxies.

    Spitzer observations also show that, unlike most known mergers, the galaxies involved in the quadruple collision lack gas, the source material that fuels star birth. Consequently, astronomers predict that relatively few new stars will be born in the new, combined galaxy.

    (Agencies)