Q:

How long does it take light to reach Earth?

A:

Light from the Sun travels 93 million miles, at a speed of 186,000 miles per second, to get to Earth in about 8 minutes and 20 seconds. People on Earth see the Sun as it was 8 minutes and 20 seconds ago.

Know More

Full Answer

People also see stars and galaxies as they were when the light reaching the Earth was first emitted. The galaxy MACS0647-JD is 13.3 billion light-years away, so the light from it just reaching Earth now was first emitted when the universe was only 400 million years old. The Sun only formed 4.5 billion years ago, so the light from that galaxy is over twice the age of the Sun.

Learn more in Measurements

Related Questions

  • Q:

    How long did it take Neil Armstrong to get to the moon?

    A:

    The Apollo 11 space mission, commanded by Neil Armstrong, took three days, three hours and 49 minutes to reach the moon after launching from Earth. However, Armstrong did not set foot on the moon for more than six hours after landing.

    Full Answer >
    Filed Under:
  • Q:

    Why do humans need light?

    A:

    Light is necessary for the survival of life on Earth, as almost all energy used by life is derived from the sun. Plants and algae use light energy in photosynthesis, which provides usable chemical energy for heterotrophic organisms. In addition, without light, the Earth would be completely cold and dark, as even the moon gets its glow from reflecting the sun.

    Full Answer >
    Filed Under:
  • Q:

    How long does it take for light from the moon to reach the Earth?

    A:

    It takes light from the moon's surface approximately 1.3 seconds to reach the Earth. This is also the amount of time it takes for sound to travel from the Earth to the moon. That means that communication from the Earth to an astronaut on the moon has a 2.6-second delay.

    Full Answer >
    Filed Under:
  • Q:

    How long does it take to get from Earth to Jupiter?

    A:

    The average distance between Earth and Jupiter is 483 million miles, so it would take 43 minutes to travel from Earth to Jupiter at the speed of light. However, the distance between Earth and Jupiter is always changing; therefore, the time to reach Jupiter from Earth varies.

    Full Answer >
    Filed Under:

Explore