0 results
Milky Way ancient merger


Ancient Merger Wreckage in the Milky Way

Mounting evidence indicates that our galaxy smashed up another smaller galaxy roughly 10 billion years ago.

Illustration of stars sprinting through our Galaxy

Milky Way

Some Stars Around Galaxy May Be From Elsewhere

Data from the Gaia satellite reveal 20 new high-speed stars, 13 of which appear to have originated outside of the Milky Way.

Artist's impression of galactic encounter's aftereffects

Milky Way

Pattern in Milky Way's Stars Suggests Recent Galactic Whack

An unexpected pattern in the Milky Way's disk of stars points to a recent whack from another galaxy.

Gaia's map of 1.7 billion stars in the Milky Way and beyond

Spacecraft and Space Missions

Gaia Maps 1.7 Billion Stars, Widens Cosmic Census

With its second data release, the European Space Agency's Gaia satellite has redefined the way we look at our galaxy.

Milky Way

New Mass Estimate for the Milky Way

Astronomers have observed the motion of distant star clusters to measure our galaxy’s mass. The new estimate places the Milky Way in the lightweight class of galaxies.

HI4PI maps Milky Way's neutral hydrogen


Astronomers Map Milky Way in Incredible Detail

Astronomers have mapped neutral atomic hydrogen, which profuses the space between stars, in unprecedented detail to create a beautiful radio-wavelength portrait of the Milky Way.

Milky Way Galaxy, NASA / JPL-Caltech

Astronomy Questions & Answers

What percentage of our galaxy’s stars move in retrograde orbits?

Do astronomers have any idea what percentage of our galaxy’s stars move in retrograde orbits? The short answer is yes, a very small percentage. But the long answer is more interesting. First, let’s agree what we mean by “retrograde.” If you were to look down on the solar system from…