Jump to content

Narrowband

Altitude of the planets for the next few years


cuivenion

Recommended Posts

I started a wee project a few months ago calculating the apparent positions of the planets in C++, using a library called aaplus. I've just modified it to print me out the apparent altitudes of each planet crossing my meridian, between sunset and sunrise, every week for the next 15 years.

Or at least I think that's what I did...

planets.jpg

Edited by furrysocks2
x axis to jan 1st
  • Like 14
Link to comment
Share on other sites

2 hours ago, furrysocks2 said:

I started a wee project a few months ago calculating the apparent positions of the planets in C++, using a library called aaplus. I've just modified it to print me out the apparent altitudes of each planet crossing my meridian, between sunset and sunrise, every week for the next 15 years.

Or at least I think that's what I did...

planets.jpg

Outstanding!

... a shame how low Saturn is while the rings are so open. I didn't realise how low Jupiter will be.  The curves for Mars are very interesting - especially for 2018-19.

Nice work :thumbsup:

  • Like 2
  • Thanks 1
Link to comment
Share on other sites

15 minutes ago, furrysocks2 said:

mars.jpg

Nice work. I was about to post that for Mars you need to tie the altitude into the closeness to opposition and visibility. My table shows that Mars is still very low at opposition in 2018/19 unfortunately.

 

IMG_9323.PNG

  • Like 5
Link to comment
Share on other sites

12 minutes ago, Stu said:

Nice work. I was about to post that for Mars you need to tie the altitude into the closeness to opposition and visibility. My table shows that Mars is still very low at opposition in 2018/19 unfortunately.

I think my graph and your table show the same thing though I'm a few degrees further north so altitude is a little lower.

For Mars, the red trace shows meridian transit altitude when it occurs between sunset and sunrise. Currently the blue trace shows daytime transit altitude, but I could change that to show maximum nighttime altitude - the same thing when a meridian transit is visible, but more useful from an observer's point of view when transit is not visible.

Ideally, I'd like to graph all of this for all planets, perhaps by scaling line thickness or colour intensity according to relative diameter, but not sure a spreadsheet will let me do that. I could perhaps use error bars, but it might get cluttered.

  • Like 2
Link to comment
Share on other sites

I should perhaps stop posting random graphs on this thread, but thought it worth posting a concluding image showing the next couple of Mars oppositions and its maximum nighttime altitude from my location (56N) - meridian transits are shown and relative apparent angular diameter is shown. Note: the error bars have nothing to do with altitude, they're just there to indicate relative size - also they don't really work on a steep gradient. :/

I hope it's correct. 

mars.jpg

Edited by furrysocks2
  • Like 4
Link to comment
Share on other sites

1 hour ago, festoon said:

I might be dead before I see Saturn high in the sky again ?

And it's nice to see that we should enjoy Jupiter this year ?

This is great work, thank you!

Get yourself down south somewhere with a good enough scope then, and the planets will be lovely and high in the sky. Combine it with a nice holiday and what is there to lose? :) 

  • Like 4
Link to comment
Share on other sites

2 hours ago, furrysocks2 said:

I think my graph and your table show the same thing though I'm a few degrees further north so altitude is a little lower.

Absolutely, our information is totally in line. Mine is simplified just to concentrate on oppositions, yours shows far more info and is really well put together. A great piece of work, and something that is worth building on for other planets as you say, although it is most useful for the ones with huge apparent size changes like Mars.

  • Like 2
Link to comment
Share on other sites

Thanks, folks - glad it's useful, for me too. The reason I started doing calcs was mainly for fun, but hoped I could do some sort of forecasting like this. Tweaking the software is easy

Code looks something like this, for anyone interested:

const auto now = chrono::system_clock::now();
for (chrono::system_clock::time_point t = now; t < now+(5*365*24h); t+=7*24h)
{
    const auto mars_dia = CAAPhysicalMars::Calculate(aa_date(t).Julian(), false).d;

    std::cout
        << get_max_and_transit_alt<Mars>(LOCATION, t) << "," << mars_dia << ","
        << get_max_and_transit_alt<Jupiter>(LOCATION, t) << ",,"
        << get_max_and_transit_alt<Saturn>(LOCATION, t) << ",,"
        << get_max_and_transit_alt<Uranus>(LOCATION, t) << ",,"
        << get_max_and_transit_alt<Neptune>(LOCATION, t) << ",,"
        << "\n";
}

 

 

13 minutes ago, Stu said:

... it is most useful for the ones with huge apparent size changes like Mars.

True.

 

 

Edited by furrysocks2
  • Like 1
Link to comment
Share on other sites

34 minutes ago, Stu said:

Get yourself down south somewhere with a good enough scope then, and the planets will be lovely and high in the sky. Combine it with a nice holiday and what is there to lose? :) 

Completely agree...?

Funnily enough, at kelling Heath this weekend...but rubbish weather and even if it was clear...full moon...

 

Link to comment
Share on other sites

22 minutes ago, furrysocks2 said:

Thanks, folks - glad it's useful, for me too. The reason I started doing calcs was mainly for fun, but hoped I could do some sort of forecasting like this. Tweaking the software is easy

Code looks something like this, for anyone interested:


const auto now = chrono::system_clock::now();
for (chrono::system_clock::time_point t = now; t < now+(5*365*24h); t+=7*24h)
{
    const auto mars_dia = CAAPhysicalMars::Calculate(aa_date(t).Julian(), false).d;

    std::cout
        << get_max_and_transit_alt<Mars>(LOCATION, t) << "," << mars_dia << ","
        << get_max_and_transit_alt<Jupiter>(LOCATION, t) << ",,"
        << get_max_and_transit_alt<Saturn>(LOCATION, t) << ",,"
        << get_max_and_transit_alt<Uranus>(LOCATION, t) << ",,"
        << get_max_and_transit_alt<Neptune>(LOCATION, t) << ",,"
        << "\n";
}

 

 

True.

 

 

Hey thanks for sharing your code - I was wondering about asking if you would mind :):thumbsup:.

I will have to look up that lib you mentioned earlier.

Cheers,

-Niall

  • Like 1
Link to comment
Share on other sites

5 minutes ago, niallk said:

Hey thanks for sharing your code - I was wondering about asking if you would mind :):thumbsup:.

I will have to look up that lib you mentioned earlier.

Cheers,

-Niall

I'll pop a thread up later on when I've more time.

I got the calcs running on an Arduino, that was fun. It's a library implementation of a book. http://www.naughter.com/aa.html

 

Edited by furrysocks2
added link
  • Like 1
Link to comment
Share on other sites

And I've redone Mars in the same way:

mars 5y.jpg

mars 10y.jpg

 

[Edit: in an effort to verify my own work, see https://www.uapress.arizona.edu/onlinebks/MARS/APPENDS.HTM:

Quote
Opposition Date Diameter
2018 Jul 27 24.1"
2020 Oct 13 22.3"
2022 Dec 8 16.9"
2025 Jan 16 14.4"

The dates line up pretty well and looking at my raw data, I'm within an arc-second of apparent angular size - the distance to Mars over the next few oppositions is increasing.

mars increasing.jpg

Credit: https://in-the-sky.org/solarsystem.php]

 

Edited by furrysocks2
verification
  • Like 4
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.