Astronomy for Beginners

Here’s where you’ll find observing guides, how-to articles and great astronomy hints and tips. Don’t forget to also check out our comprehensive astronomy dictionary.

Astronomy Dictionary
Afocal coupling

The technique of imaging through a camera lens held up to the eyepiece of a telescope. It is used for cameras with non-removable lenses.


The distance to a star if it has a parallax angle of 1 arcsecond (1/3,600 of a degree). One parsec is equal to 3.26 lightyears.

Pancam camera

This is the high-resolution stereo panoramic camera (pancam) that the Mars Exploration Rovers Spirit and Opportunity are equipped with. It is used to give a geological overview of a region and to navigate the martian surface, as well as to choose what places are potentially interesting for the science instruments to study.

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