One thing I lack now is a representation for where Aldebaran is.

I tried writing a script that used the example in Star.pm. In it, it required me to turn right ascension into radians, and after the script pooped out, I realized that all I needed to start making comparisons was its fixed value in radians.

$ ./7.astro.pl 
./7.astro.pl 
Name    Right Ascension        Declination 
Mars    1.18463017264379    0.407948808088123 
Moon    1.51448031651065    0.422740932680421 
Aldeb    1.20392811802569    0.288139315093836  
Time is Sun Mar 21 00:39:59 2021 
Julian day is 2459294.7777662 
$ pt 7.astro.pl 
$ cat 7.astro.pl <-I do this to be correct and use STDOUT to list reli
+ably

[download]
#!/usr/bin/perl 

use Time::Piece;
use Astro::Coord::ECI::Utils 'deg2rad';
use Astro::Coords;
use Log::Log4perl;

my $file = '/home/hogan/Documents/hogan/logs/3.log4perl.txt';

# unlink $file or warn "Could not unlink $file: $!";
my $log_conf4 = "/home/hogan/Documents/hogan/logs/conf_files/3.conf";
Log::Log4perl::init($log_conf4);    #info
my $logger = Log::Log4perl->get_logger();
$logger->info("$0");

$logger->info("Name\tRight Ascension\t\tDeclination");

for my $name (qw/Mars Moon/) {

  my $planet2 = Astro::Coords->new( planet => $name );

  $planet2->datetime( Time::Piece->new );

  my $ra  = $planet2->ra( format => q/rad/ );
  my $dec = $planet2->dec( format => q/rad/ );

  $logger->info("$name\t$ra\t$dec");

}

my $aldeb_ra_degrees          = 68.98;
my $aldeb_ra_radians          = deg2rad($aldeb_ra_degrees);
my $aldeb_declination_degrees = 16.509166666667;
my $aldeb_dec_radians         = deg2rad($aldeb_declination_degrees);
$logger->info("Aldeb\t$aldeb_ra_radians\t$aldeb_dec_radians ");
my $t  = localtime;
my $jd = $t->julian_day;

$logger->info("Time is $t");
$logger->info("Julian day is $jd");

__END__

[download]

So, the data is bunching together well, but I'm not completely sure how I'd go about figuring out when something crosses between. For me, it's a tantalizing triangle.

I would think that we should think of these creatures as two-vectors of radians. Then my question now is this: if these are 3 traveling 2-vectors (one is stationary for this script), how do I write a function to calculate betweenness? It seems clear to me that I would need to invoke a telescope method.

I also wonder if everyone in the world could have had a chance to see this (less light pollution)?

In reply to Re: Deciding when the moon passed between aldebaran and mars by Aldebaran
in thread Deciding when the moon passed between aldebaran and mars by Aldebaran

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