Why does the cloud of Orion Nebula appear more distinct when I am not directly looking at it? I have a 6cm aperture newtonian refractor telescope through which I saw the Orion Nebula yesterday night. As all you can hope with a telescope of such a small aperture, I saw some faint cloudy structure, but when I looked away from the cloud through the telescope it appeared to be more distinct and dense. Why is it so?
This is called the Averted vision. It involves not looking directly at the object, but looking a little off to the side.

How does it works?

Because the retina is less sensitive at the center, and this is very remarkable on the very faint objects (like nebulas or galaxies)

This is a common technique used by astronomers.

More info here

How to make the most of Averted vision?

To maximise the effects of your Averted Vision, you first need to know which eye is your dominant eye. To do so:


Point with your finger a distant object
Then blink an eye, then the other eye.
The eye in which your finger is perfectly aligned with the object is your dominant eye.


Then, for the best Averted vision:


Look at the top-right of the object if your dominant eye is the right one
Look at the top-left of the object if your dominant eye is the left one