The question of whether humans ventured to the moon or otherwise remains a favourite conspiracy theory topic. One of the questions always asked regarding this topic regards the inability to observe the flag, and indeed any other items left behind by the astronauts, from the Earth. This is indeed a very good question, but the answer is also rather simple.

Even though the Earth and the moon are rather close on a cosmic scale, varying in distance between 350,000km and 400,000km, attempting to observe something as small as a lunar excursion module, or indeed the flag left behind by Neil Armstrong during the Apollo 11 mission, is extremely hard. It is easy to mistakenly assume that something so close should be easier to see than a galaxy millions of light years away. The truth, however, is that galaxies are massive structures, themselves thousands of light years across, meaning that it is indeed easier to see them. The telescope required to resolve something like a one-metre flag on the moon from Earth would need to be some 200 metres wide for optical wavelengths!