Question

How long does it take for a radio signal to go from Earth to Mars?

Asked by: Richard Boulais

Answer

Radio signals are electromagnetic waves, such as light or X-ray. The speed of electromagnetic waves in vacuum, is 300000km/sec (approximately).

In order to calculate the time of travel with this speed from Earth to Mars, we need to know the distance.

When the Mars and the Earth are at the opposite sides of the Sun, the distance is the largest: approximately: 378 million km. The time needed for an electromagnetic wave to cover this distance is approximately: 21 minute.

The closest distance between Mars and Earth is 78 million km, the time in this case is: 4.3 min.

So the time of travel between Earth and Mars is between 4.3 minutes and 21 minutes, depending on the actual distance between the two planets.

Answered by: Ferenc Szekely, Ph.D., Physicist, ELTE, Budapest, Hungary

Search

Loading



Click here to get
a FREE ride with Uber!


Click here to
sign up for Birchbox






Science Quote

'If one wishes to obtain a definite answer from Nature one must attack the question from a more general and less selfish point of view.'

Max Planck
(1858-1947)
Science Sidebar | Science Education Articles
10 Ways to Keep Your Kids Interested In Science

Young children are natural scientists: they ask questions, pick up sticks and bugs outside, and are curious about the world around them. But as they get a bit older, many kids gradually lose their interest in science. They might see it as just another task at school, something that doesn't apply to their lives. Of course nothing could be further from the truth, so here are ten ways you can remind your kids that science is everywhere. Most of these are fun for adults, too! Continue reading ...

Top Selling

Here are our physics & astronomy bestsellers:
Deluxe Water Rocket Set
Magnetic Levitator - Classic
Scorpion, Ant, Wasp and Flower Bug
12 inch Galileo Thermometer
Revolving Multi-Color Fiberoptic Light
Solar Radiometer
Enviro Battery 4M Kit
Tin Can Robot 4M Kit
Wood Grain Newtons Cradle
Brush Robot 4M Kit

Sponsors

USC University of Southern California Dornsife College Physics and Astronomy Department McMaster University Physics and Astronomy Department