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.
'How To' Guides
Astronomy Dictionary
Imbrian period
The period in the Moon’s history when the large basins Imbrium, Crisium, Tranquilitatis, Serenitatis, Fecunditatis and Procellarum were formed, and filled with basalts. The Imbrian period occurred between 3.8 and 3.2 billion years ago.
Superior conjunction
This is when one of the inferior planets (Mercury or Venus) is positioned directly behind the Sun in its orbit, as seen from the perspective of an observer on Earth. They are therefore hidden from view.
