How to query posts that are not related to any term of a taxonomy?

Probably something like this:

$records = new WP_Query( array(
    'post_type' => array('record'),
    'post_per_page' => -1,
    ) );


while ( $records->have_posts() ) : $records->the_post();

  $terms = wp_get_post_terms( get_the_ID(), 'planets' );
  if ( count( $terms ) === 0 ) {
    echo 'Post ID: ' . get_the_ID() . '<br />';
  }

endwhile;
wp_reset_postdata();