- History of email (Wikipedia)
The history of email entails an evolving set of technologies and standards that culminated in the email systems in use today.
- Perseids (PER) (meteorshowersonline.com)
This is the most famous of all meteor showers. It never fails to provide an impressive display and, due to its summertime appearance, it tends to provide the majority of meteors seen by non-astronomy enthusiasts.
- Perseids (Wikipedia)
The Perseids are a prolific meteor shower associated with the comet Swift–Tuttle that are usually visible from mid-July to late-August. The meteors are called the Perseids because they appear from the general direction of the constellation Perseus and in more modern times have a radiant bordering on Cassiopeia and Camelopardalis.