If the Milky Way contained only the mass observed in stars, gas, and other baryonic (ordinary) matter, the rotational speed would decrease with distance from the center.

Feb 9, 2026 · The stars in the Galaxy, especially along the Milky Way, reveal the presence of a general, all-pervasive interstellar medium by the way in which they gradually fade with distance.

Apr 18, 2023 · The Milky Way galaxy is our cosmic home. A barred spiral galaxy stretching 100,000 light-years across. Here we explore our galactic neighborhood in more detail.

May 19, 2025 · The Milky Way is 105,700 light-years wide while the Andromeda Galaxy is 220,000 light-years in width. By the way, the Local Group — a group of multiple galaxies including the Milky Way …

Dec 24, 2025 · It’s much wider than it is tall — Boylan-Kolchin says the width of the Milky Way stretches about 80,000 to 100,000 light-years from end to end, or 40,000 to 50,000 from the center to the …

Our planet is part of a solar system that rotates in one of the smaller galactic branches known as the Local Arm. Earth’s Sun is roughly two-thirds of the way out from what is probably a black hole at the …

The Milky Way Galaxy is our home in the vast universe. It is a barred spiral galaxy that contains over 100 billion stars, including our own Sun. Spanning more than 100,000 light-years in diameter, the …

Dec 4, 2025 · Our solar system is located in the Milky Way, a barred spiral galaxy with two major arms, and two minor arms. Our Sun is in a small, partial arm of the Milky Way called the Orion Arm, or …

So, if our 'Milky Way is 100,000 light years across (as stated above) then this would take 100,000 earth years at light speed of 186,000 miles per second to get from one side to the other.

Out of convenience, astronomers use a unit of distance that is defined as the distance of an object with an annual parallax of 1 arc second. This distance is the parsec, abbreviated as pc; it is the natural …