Marco Castellani c/o Osservatorio Astronomico di Roma Via Frascati, 33 00078 Monteporzio Catone Italy
- Indirizzo email: http://scr.im/mcastel
- Facebook: https://www.facebook.com/marco.castellani
- Mastodon (IT): https://poliversity.it/@mcastel
- Mastodon (EN): https://social.vivaldi.net/@mcastel
- Pixelfed Porfolio: https://pixelfed.uno/i/portfolio/mcastel
- Feddit: https://feddit.it/u/mcastel
- PeerTube: https://peertube.uno/a/mcastel
- Telegram: http://t.me/mcastel