Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/3/84; site aplvax.UUCP Path: utzoo!watmath!clyde!burl!ulysses!allegra!mit-eddie!godot!harvard!seismo!umcp-cs!aplvax!ded From: ded@aplvax.UUCP (Don E. Davis) Newsgroups: net.movies Subject: Re: Re: 2010 Message-ID: <820@aplvax.UUCP> Date: Mon, 17-Dec-84 21:43:23 EST Article-I.D.: aplvax.820 Posted: Mon Dec 17 21:43:23 1984 Date-Received: Wed, 19-Dec-84 02:22:53 EST References: <> <152@lasspvax.UUCP> <786@milo.UUCP> Distribution: net Organization: JHU/Applied Physics Lab, Laurel, MD Lines: 29 > > How long it takes for a radio transmission round trip to Jupiter? I seem > to remember ground control getting upset that they hadn't heard a response > to a request sent an half hour earlier. Is this reasonable? (I thought I > remembered a bigger fuss being made over this in 2001.) > > -- > eric > ...!seismo!umcp-cs!aplvax!milo!eric Well, Eric, my son Mark is heavy into 2nd grade astronomy, so I put your question to him. He glanced up from his differential equations and said, "Gee, Dad, everyone knows that the average radius of Earth's and Jupiter's orbits are 1.4957E8 km and 7.7814E8 km, respectively, so, ignoring Aphelion and Perhelion for now we have a min and max separation of 6.29E8 and 9.28E8 km. Therefore, at 300,000 km per second, radio waves would require about 70 to 104 minutes to make the round trip. If you want a more precise value, you'll gonna have to wait 'til I enter 3rd grade." I hope this answers your question. It might even be accurate. -- Don Davis JHU/APL ...decvax!harpo!seismo!umcp-cs!aplvax!ded ...rlgvax!cvl!umcp-cs!aplvax!ded