Milky Way much more massive than previously thought / Li Via Galactic plu massiv quam pensat anteriorimen

Li Galaxe de Andromeda, li max proxim galaxe a nor Via Galactic.

It's interesting to see what we know of our own galaxy develop over time since it's the one galaxy we're not capable of viewing from the outside, making it that much harder to know about for sure. In a paper presented yesterday, it turns out that the Milky Way is about 50% more massive than previously thought:

Scientists have dramatically revised the mass of the Milky Way, saying our home galaxy is half again as heavy as previously thought.

The Milky Way is now on par with the nearby Andromeda Galaxy in terms of heft. The Milky Way spins a lot faster than was thought, too.

One reason why this is important is the following:

The new mass for the Milky Way is 3 trillion solar masses, Reid said, and that larger mass, in turn, means that the Milky Way exerts a greater gravitational pull that increases the likelihood of collisions with Andromeda or other smaller nearby galaxies.

The collision won't be for billions of years however, so no need to worry. Also, due to the immense distances between stars there is almost no chance of actual stars colliding:

As with all such collisions, it is unlikely that objects such as stars contained within each galaxy will actually collide, as galaxies are in fact very diffuse—the nearest star to the Sun is in fact almost thirty million solar diameters away from the Earth. (If the sun were scaled to the size of an American quarter, 24.26 mm, the next closest quarter/star would be 700 km away.)

So it looks like the following simulation and others like it will need to be updated with a slightly larger version of the Milky way: