The Andromeda galaxy

Classical Mechanics Level 1

The Andromeda galaxy is a giant spiral cluster of stars whose mass is that of $300$ billion Suns. You can see it with the naked eye as a faint elongated cloud in the night sky. Inasmuch as it subtends an angle of $4.1^{\circ}$ and is known to be larger than our own galaxy [ $163 \times 10^3$ light-years (units of ly) in diameter for Andromeda as compared to $100 \times 10^3$ light-years for our galaxy], how far away is it in light-years?

Excel in math and science

Master concepts by solving fun, challenging problems.

It's hard to learn from lectures and videos

Learn more effectively through short, interactive explorations.

Used and loved by over 7 million people

Learn from a vibrant community of students and enthusiasts, including olympiad champions, researchers, and professionals.

The Andromeda galaxy

Excel in math and science

Master concepts by solving fun, challenging problems.

It's hard to learn from lectures and videos

Learn more effectively through short, interactive explorations.

Used and loved by over 7 million people

Learn from a vibrant community of students and enthusiasts, including olympiad champions, researchers, and professionals.

Learn from a vibrant community of students and enthusiasts,
including olympiad champions, researchers, and professionals.

Learn from a vibrant community of students and enthusiasts,
including olympiad champions, researchers, and professionals.