The view of an object that is 440 light-years away from Earth is always a view of the past. This is because:
- A light-year is a unit of distance, not time. It's the distance that a beam of light travels in one Earth year, which is about 5.88 trillion miles (9.46 trillion km).
- Light has a finite speed. Although it is incredibly fast (about 186,000 miles or 300,000 km per second), it still takes time to travel the vast distances of space.
- The farther away an object is, the longer its light takes to reach our eyes or telescopes. Therefore, when we observe something 440 light-years away, we are seeing the light that left that object 440 years ago.
For example, when astronomers observe the Pleiades star cluster, which is 440 light-years away, they see it as it was 440 years ago, around the time Queen Elizabeth I was on the English throne. Similarly, the sunlight we see on Earth is about 8 minutes old, and light from the nearest star system, Alpha Centauri, is 4.3 years old.
