Angular size is proportional to size/distance, so the calculation you're trying ...

		penteract 27 days ago \| parent \| context \| favorite \| on: Long-distance and wide-area detection of gene expr... Angular size is proportional to size/distance, so the calculation you're trying to do is correct; however, 50700 km is more than 1e7 meters so the angular sizes differ by about 3 orders of magnitude.