The Milky Way is expanding faster than the speed of sound

At a rate of about 1,770km / h, the Milky Way could increase in size by about 5% after three billion years.

The new research shows that the Milky Way is expanding with new stars being born, Space reported on April 4. The Milky Way is about 100,000 light-years wide and is estimated to contain several hundred billion stars.

NGC 6744 galaxy has a spiral form similar to the Milky Way.(Photo: Space).

"The Milky Way is already very large. We found, at least the observable part of the Milky Way is gradually increasing in size as new stars form at the outer edge. If possible, pass through time and observe. The Milky Way is three billion years later, you will see that it is about 5% larger now , " said the study's lead author, Cristina Martínez-Lombilla.

Direct assessment of the expansion of the Milky Way is difficult because the Earth is in the center. Therefore, Martínez-Lombilla and her colleagues conducted additional observations of other spiral galaxies.

The team analyzed the outer edge of some spiral galaxies through optical data collected by Sloan Digital Sky Observatory (SDSS), near-infrared and near-ultraviolet data from space telescopes. Spitzer and GALEX of NASA. GALEX and Spitzer were launched into space in 2003. While GALEX was discontinued in 2013, Spitzer is still active.

The star formation and movement observed by the team showed that galaxies like the Milky Way are expanding at a rate of about 1,770 km / h, 1.4 times the speed of sound on Earth.

In the case of the Milky Way, this growth will be overwhelmed for about 4 billion years due to the collision with the Andromeda spiral galaxy. These two spiral galaxies will merge and form the "Milkdromeda" super galaxy .