Approximately how long would it take to send a message from earth to, and receive a confirmation from, a spacecraft orbiting Jupiter, if the planets are in alignment with the sun?

Radio waves travelling at 300,000 km/second would take approximately 35 minutes to reach a satellite orbiting Jupiter depending on alignment, and the same time to travel back to Earth, equaling about 1.2 hours. Jupiter's mean distance from the Sun is @ 783 million km., subtract 16 minutes for the time radio waves travel from the Earth to the Sun, and go from there.

The math:

(783 million km (distance to Jupiter from the Sun) divided by 300,000km per second (speed of light)= 2610 seconds, divided by 3600 (seconds in an hour) = approximately .725 hours, minus .13 hours (8 minutes from radio signals to and from the Sun) =.59 hours, times 2 (round trip radio wave) = approximately 1.18 hours if Earth and Jupiter are in alignment with the Sun.

More Info: www.qrg.northwestern.edu

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53 Comments

Lemar Blackheart

Who the hell would know this answer...

Tom Fulton

1.18 hours is hardly approximate?

Jennifer Mann

To those of you complaining that this is not trivia...just because you don't know the answer doesn't make it "not trivia" (sorry for the double negative). Trivia is trivial information that you wouldn't use in your regular lives - seems to fit perfectly.

Judy West

Lemar, I loved your answer. I chuckled because that's what I would have said, or maybe "Oh my heck!" (We use that a lot here in Utah.) I had no idea, either, so I guessed by deduction. Who would put a decimal like 1.18 hrs, if that weren't the right answer? All the other choices were whole hours. I figured a scientist would have gone to that extra trouble. So by luck, I was right.

David Colloby

It was the only answer to specific decimal places

Glynis Rix

Judy West, clever you!

elizawheeler

Always pick the number that isn't rounded up or down.

james parrillo

Char, I think he Mr. Chalk was saying how he knew the answer, since many did not. I never delved into that much astronomy or physics information in any class. Maybe, the science curricula in Australia are, in general, more comprehensive than in America. Thank you, Christine, James' wife

james parrillo

stormejohn, Do you know? Is there a speed of sound, like thunder? I wonder why the calculation uses the speed of light, rather than a speed of sound. Then, to reach the planet, if it were possible, in a spacecraft would take longer? I never had more than a few months of the first high school year in introduction to some simple physics terms. The rest of the year was Latin. I wish I could have had years of that, like some QuizzClub players have reported they had. Thank you, Christine, James' wife

Jas Newman

Saverio M Rinaldi, Or passenger pigeon or—worse—USPS..

Jas Newman

Dirk Byker, Thank you for saving me the trouble of pointing this out. I now add only that the question failed to mention radio. I was thinking of a passenger pigeon.

Stephen W. Gerrard

Seems to me that the approximate answer is 1 hour and 1.18 hrs would be the actual time.

Dennis Walker

Accurate calculation can only be made by a mathematically minded scientist… less than 0.1% of population could confidently answer this “simple quiz question” A 🍍 should have been one answer

Dirk Byker

There are two alignments with the sun: at conjunction and at opposition. at conjunction earth and Jupiter are furthest apart; at opposition they are the closest.