How many arcminutes is the moon

An arcminute can also be divided into 60 arcseconds abbreviated 60 arcsec or 60". If you extend your hand to arm's length, you can use your fingers to estimate angular distances and sizes in the sky.

The angular sizes of objects show how much of the sky an object appears to cover. Angular size does not, however, say anything about the actual size of an object. If you extend your arm while looking at the full moon, you can completely cover the moon with your thumb, but of course, the moon is much larger than your thumb, it only appears smaller because of its distance. How large an object appears depends not only on its size, but also on its distance. The apparent size, the actual size of an object, and the distance to the object can be related by the small angle formula :.

A certain telescope on Earth can see details as small as 2 arcsec. What is the greatest distance you could see details as small the the height of a typical person 1.

This is much less than the distance to the Moon approximately , km so this telescope would not be able to see an astronaut walking on the moon. Originating website can be found here. But there is more to this phenomenon of the apparent Moon size than that The second effect is an illusionary one.

For a variety of reasons having to do with how the human eye and brain work together, the human brain interprets a full moon lying near the horizon to appear larger than when it lies high in the sky, away from the horizon.

You can test for yourself that the Moon's angular diameter is exactly the same near the horizon as it is when it is up high in the sky, by holding an object at arm's length whose angular size matches that of the moon see also the top photo.

You can go here , here , here , and here for further information about this illusion - the psycho-physiological explanations are still controversial! NASA has a webpage providing a nice summary of the problem and several links for more information. The same illusion applies to a rising or setting Sun.

Now sometimes these effects can work together to produce a "really big Moon" as it lies near the horizon. A rising or setting full Moon that lies at perigee its closest approach to Earth will indeed appear to loom extra large along the horizon.

Part of the effect is real, part is an illusion.