Calculation of the distance between planets on a given date

[member 656954]

I'm working on a novel and the action has moved off Earth and into the asteroid belt. I've been using a few websites and apps - notably AstroGrav, Stellarium, and Atlas InfoGraphics - to figure out where objects are in the solar system at the future date of the novel. But I can't find a way to accurately calculate distances between objects. So, I know how far out Ceres 1 is from the Sun, and how far Earth is for example, but trig fails to calculate the distance between them without angles and the apps don't give that value. I could plot-paper for a single date, but that's cumbersome and does not scale for the time frames I need.

Does anyone know of an orrery type app that calculates inter-object distances between objects at an arbitrary date?

 

[lomidrevo]

You are probably not aware, but in Stellarium, in the Location window [F6], you can select not only long/lat position on Earth, but also select another planet. Actually many other solar system objects can be selected, not only planets. Once you do that, you can watch the sky from that perspective, and click on any other object you are interested in. As you usually, in the left corner, you will find all available info, including Distance (in AU and km).
Hint: disable Ground textures [G], which is only an unnecessary obstacle for your purposes.

 

[member 656954]

You are probably not aware

You are 100% correct, @lomidrevo, I did not know that. Thanks, I'll have a play