SUNSET: 
Close Encounters in the Milky Way — and What They Mean for Planets
New research shows stellar flybys are common in our galaxy’s crowded center. That could have both good and bad (but mostly bad) effects on growing planets.
The 10 Million-Degree Gas Around the Milky Way
New observations show ultra-hot gas around the Milky Way. Stellar explosions may have driven this gas out of our galaxy.
Magnetism Rules in the Milky Way’s Core
Recent observations from the airborne SOFIA observatory show that magnetic fields — not gravity — govern the gas at the center of the Milky Way.
Is the Milky Way Throwing Out Forming Stars?
Some of the scant stars dwelling in the Milky Way's halo may have an unexpected origin: They may come from the galaxy itself.
The Milky Way’s Warped Tutu Twirls Every 600 Million Years
Astronomers have known for decades that our galaxy is warped. Now, they can follow the warp’s rotation as it travels around the galactic center.
Nearby Stellar Nurseries Ride a Giant Wave
Astronomers have found a gigantic, undulating wave of stellar nurseries in our galaxy, just outside the Sun’s orbit in the spiral disk.
Warped Milky Way in 3D
Astronomers have used pulsating stars to trace the crooked shape of our galaxy’s disk.
Did a Dwarf Galaxy Crash into the Milky Way?
A recent study suggests the dwarf galaxy Antlia 2 had a long-ago run-in with our galaxy, rippling and warping its disk. But not everyone agrees with that scenario.
The Milky Way Contains the Mass of 1.5 Trillion Suns
Astronomers are using Gaia and the Hubble Space Telescope to make the most precise measure of the Milky Way’s mass to date. The new result puts our galaxy on par with — if not more massive than — Andromeda.
The Milky Way Is Warped in More Ways Than One
Astronomers mapping out luminous stars across our galaxy's disk found that the Milky Way is warped — and multiple factors are twisting its shape.
60-Second Astro News: A Carnivorous Quasar and a Galaxy Ghost
In astronomy news this week: The most luminous quasar known in the cosmos is devouring three galaxy companions, while a newly discovered ghostly satellite of the Milky Way hints at hordes more just waiting to be found.
Ancient Merger Wreckage in the Milky Way
Mounting evidence indicates that our galaxy smashed up another smaller galaxy roughly 10 billion years ago.
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.
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 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.
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.
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.
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…
