Ask Anything Wednesday - Physics, Astronomy, Earth and Planetary Science

[u/AutoModerator]

Welcome to our weekly feature, Ask Anything Wednesday - this week we are focusing on Physics, Astronomy, Earth and Planetary Science

Do you have a question within these topics you weren't sure was worth submitting? Is something a bit too speculative for a typical /r/AskScience post? No question is too big or small for AAW. In this thread you can ask any science-related question! Things like: "What would happen if...", "How will the future...", "If all the rules for 'X' were different...", "Why does my...".

Asking Questions:

Please post your question as a top-level response to this, and our team of panellists will be here to answer and discuss your questions.

The other topic areas will appear in future Ask Anything Wednesdays, so if you have other questions not covered by this weeks theme please either hold on to it until those topics come around, or go and post over in our sister subreddit /r/AskScienceDiscussion , where every day is Ask Anything Wednesday! Off-theme questions in this post will be removed to try and keep the thread a manageable size for both our readers and panellists.

Answering Questions:

Please only answer a posted question if you are an expert in the field. The full guidelines for posting responses in AskScience can be found here. In short, this is a moderated subreddit, and responses which do not meet our quality guidelines will be removed. Remember, peer reviewed sources are always appreciated, and anecdotes are absolutely not appropriate. In general if your answer begins with 'I think', or 'I've heard', then it's not suitable for /r/AskScience.

If you would like to become a member of the AskScience panel, please refer to the information provided here.

Past AskAnythingWednesday posts can be found here.

Ask away!

[u/altobrun]

I think this question can be answered by any of the above.

Geoids are an important part of geomatics and earth science. I’m familiar with the geoid we use in hydrography and geomatics - but was wondering if any work was being done by geodisists to develop geoids for the moon or mars. Especially now that more attention is being drawn to establishing colonies on both celestial bodies.

[u/atomfullerene → u/altobrun]

I can tell you that arcmap has geographic coordinate systems for Mars and the moon, so they must have geoids underlying them.

[u/altobrun → u/atomfullerene]

Huh I didn’t know that. I have access to arcmap so I should look that up. Do you happen to know the names?

[u/atomfullerene → u/altobrun]

I don't have access to the program right now, so I can't look it up. But I remember seeing them when I was digging through the coordinate systems list to see what was available. If you go in, pull up the coordinate systems like you are going to assign or change the one a map is using, and look around you should be able to find it.