Unlike the minuscule proper motion of stars, the planets constantly move relatively rapidly across the sky, so the coordinates will be different each time they are calculated.

#!/usr/bin/perl

use strict;
use warnings;
use Time::Piece;
use Astro::Coords;

while () {

  system 'clear';

  print qq/Planet\tRight Ascension\t\tDeclination\n/;

  for my $name (qw/Jupiter Saturn/) {

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

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

    my $ra  = sprintf('%.12f', $planet->ra(format => 'deg'));
    my $dec = sprintf('%.12f', $planet->dec(format => 'deg'));

    print qq/$name\t$ra\t$dec\n/;
  }
  sleep 1
}
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