Re: How far is Jupiter from Saturn?

The question: "How far is Jupiter from Saturn? I am asking this because it is for a school project, and I can't find it anywhere."

First, I am of the opinion that you did not try very hard to find an answer. An Internet search of "planets" would have returned many useful Internet sites. Nevertheless, I am going to answer your question because it will be of interest to other users of this site.

There are at least three different answers to your question, depending on exactly what you mean by "how far". "How far" can mean

• the apparent angular separation in our sky, or
• the actual physical distance of the current positions of the two planets, or
• the difference between the mean orbital radii of the two planets.

For the first: You can find many sources of determining the sky positions of the planets, such as many of the software items at midnightkite.com. According to the software I have, Jupiter is currently (10 Novermber 2008, 12:47 local time) at Right Ascension 19h20m and Declination S22^o31m, while Saturn is at Right Ascension 11h20m and Declination N6^o12m (see this article at Wikipedia). So we could say that Jupiter is 8h0m in R.A. and -28^o43m in Declination away from Saturn in our sky.

For the second: Again using planetary software, we can find that Jupiter is at a distance of 5.56 AU from the Sun while Saturn is 9.85 AU from the Sun, and Earth is 0.99 AU from the Sun (see Astronomical Unit at Wikipedia). Using a triangle-computing program and inputting the available information from the paragraph above it is possible to determine that, roughly, Jupiter is 14.5 AU from Saturn in actual distance across the Solar System. Since an Astronomical Unit is defined to be about 1.5x10⁹ meters, the separation of Jupiter and Saturn (on the date given above) is about 2.2x10¹⁰ meters.

For the third: You can easily find that the mean orbital radius of Jupiter is 5.20 AU while that of Saturn is 9.54 AU, for a difference of 4.34 AU, or we can use the actual numbers for 10 November 2008, 5.56 AU and 9.85 AU, to say that on that date the difference is 4.29 AU.

Depending on what you mean by "how far", I have given three different answers.

John Link, MadSci Physicist