SCIENCE: ALPHA CENTAURI

The nearest galaxy to ours is Alpha Centauri, which is nearly 25,000,000,000,000 miles away. A spacecraft launched from Earth and traveling at 23,000 miles an hour, which is achievable, would take six months to reach the sun, which is 93,000,000 miles away. It would take that spacecraft more than 100,000 years to reach Alpha Centauri.

It takes light from the sun 4.2 years to reach Alpha Centauri. Why the big difference? Light travels at 186,000 miles a second. A light-year, the distance that light travels in a year, is 5,900,000,000,000 miles. One minute is 60 seconds. One hour is 60 minutes. A day is 24 hours. A year is 365 days. You might need a scientific calculator to do the math. [Source: Will Black Holes Devour the Universe? & 100 Other Questions & Answers About Astronomy by Melanie Melton]