The Sun you see is no longer there

Sunlight takes a little over eight minutes to cross the 150 million kilometers that separate us from it. So when you look at the Sun, you do not see it as it is now: you see how it was eight minutes ago.

Light is the fastest thing there is, about 300,000 kilometers per second, but space is so vast that not even light crosses it instantly. To look far away, in the cosmos, is always to look into the past.

The idea grows dizzying with the stars: many are so distant that their light has been traveling for thousands or millions of years. Some of the ones you see at night may already have gone out, and no one on Earth knows it yet.

Source: NASA