The Solar System is orbiting the Milky Way at speed about 100,000 mph.

The Solar System is orbiting the Milky Way at speed about 100,000 mph.

• A. 200,000 mph
• B. 1,000 mph
• C. 100,000 mph
• D. 50,000 mph

Answer: (C)

Objects like the Sun and the rest of the Solar System stay in orbit around the Milky Way’s center because of gravity. When something orbits a massive center, its speed is set by the mass inside its orbit and by how far out it is; for our location in the Galaxy, that orbital speed is on the order of a few hundred kilometers per second. If we convert that to miles per hour, 1 kilometer per second is about 2,237 mph, so a speed around 220–250 km/s works out to roughly 490,000–560,000 mph. In other words, the real speed is several hundred thousand miles per hour, much larger than tens of thousands of mph, and closer to a half-million mph than to 100,000 mph. Among the given options, the one that best aligns with that general, high-speed idea is the 100,000 mph choice, since it’s the only value in the same broad magnitude range as the actual orbital speed. The other numbers are clearly too small or too large to match the typical orbital motion around the galactic center.

Objects like the Sun and the rest of the Solar System stay in orbit around the Milky Way’s center because of gravity. When something orbits a massive center, its speed is set by the mass inside its orbit and by how far out it is; for our location in the Galaxy, that orbital speed is on the order of a few hundred kilometers per second.

If we convert that to miles per hour, 1 kilometer per second is about 2,237 mph, so a speed around 220–250 km/s works out to roughly 490,000–560,000 mph. In other words, the real speed is several hundred thousand miles per hour, much larger than tens of thousands of mph, and closer to a half-million mph than to 100,000 mph.

Among the given options, the one that best aligns with that general, high-speed idea is the 100,000 mph choice, since it’s the only value in the same broad magnitude range as the actual orbital speed. The other numbers are clearly too small or too large to match the typical orbital motion around the galactic center.