They eventually hope to build spaceships to travel back to Earth.

How long does the light from a star take to travel to Earth?

But as the ship traveled closer to Earth, he felt something like hope rise inside him.

By comparison, sunlight takes eight minutes to travel to Earth.

Its light has taken 349.5 million years to travel to Earth.

It takes the voice communications that long to travel all the way up to the satellite and back to Earth.

They'd have to wait for radio signals to travel to Earth and back, which could take more than half an hour.

Mary and 1 are traveling to Earth to get even better help.

The delay is due to the time it takes the signal to travel to Earth.

Enough to travel to Earth and back, with lots left over.