The Milky Way: Our Home Galaxy in Numbers

The Milky Way spans about 100,000 light-years across.
It contains an estimated 100–400 billion stars.
Our Sun orbits the galaxy once every 225 million years.
The Milky Way’s total mass is roughly 1.5 trillion times the Sun’s mass.
It holds at least 100 billion planets, with possibly billions in the habitable zone.
A supermassive black hole, Sagittarius A*, sits at its center with 4 million solar masses.
The galaxy rotates at an average speed of 828,000 km/h (514,000 mph).
The Milky Way is about 13.6 billion years old, nearly as old as the universe.
It belongs to the Local Group, a cluster of over 50 nearby galaxies.
In about 4 billion years, it will merge with the Andromeda Galaxy.