The U.S. space agency, NASA
, says our galaxy, the Milky Way, and the neighboring Andromeda galaxy will crash into each other in 4 billion years in a head-on collision.
NASA scientists say the new findings end nearly 100 years of speculation about whether Andromeda would directly plow into our galaxy, or merely deliver a glancing blow as it continued moving through the cosmos.
The study co-authors say the Earth and the other seven planets in the solar system likely will not be destroyed in the titanic pile-up, but the Sun - just like many other stars - will be flung into a different part of the galaxy. In all likelihood, the Sun will complete its stellar life-cycle in an area even farther away from the galactic core than it is now.
The NASA scientists say their findings indicate that Andromeda and the Milky Way will take about 2 billion years to completely merge into a single elliptical-shaped galaxy.
At 2.5 million light-years away, Andromeda is our closest galactic neighbor.
Observations for the study were made with NASA's orbiting Hubble space telescope.
The Hubble data and reports on the consequences of the galaxy collision are outlined in three papers that will be published in an upcoming issue of the Astrophysical Journal.
Even though the Sun is expected to have enough nuclear fuel to last through the next 5 billion years, it will be heading into the late stages of its evolution when it is tossed into its new home. As it dies, the Sun will expand into a Red Giant before its final transformation into a small, dense White Dwarf.
A light-year is the distance that light inside the vacuum of outer space travels in one year - about 10 trillion kilometers.