Astronomy & Space
396 sites
http://inconstantmoon.com/
Inconstant Moon offers nightly multimedia tours of the lunar surface, complete with maps, photos, animations, and music to guide both beginners and experienced observers through the Moon's craters, seas, and phenomena. A Scientific American Sci/Tech Web Awards honoree and BBC Space featured site, it includes a Cyclopedia Selenica and Selenographia making it a comprehensive reference for lunar astronomy.
http://talkorigins.org/faqs/faq-solar.html
Written by Sverker Johansson, this detailed FAQ explores the science of solar neutrinos, nuclear fusion in the sun, helioseismology, and the famous solar neutrino problem with rigorous depth and extensive references. It also addresses creationist arguments about the sun, making it a uniquely thorough resource for both scientific education and skeptical inquiry.
https://sites.uni.edu/morgans/astro/course/Notes/section2/spectralmasses.html
A detailed reference table from a university astronomy course listing spectral types of stars across main sequence, giant, and supergiant classifications, with corresponding temperature, absolute magnitude, luminosity, and mass values. Covering everything from scorching O5 stars down to cool T8 brown dwarfs, this page serves as a compact but comprehensive stellar classification resource for students and enthusiasts alike.
https://autostakkert.com/
AutoStakkert! is free lucky imaging software created by Emil Kraaikamp for automatically analyzing, aligning, and stacking planetary and solar images captured through a telescope via high-speed video. The site offers downloads of multiple software versions (AS!2 through AS!4), sample images of Jupiter, Mars, and the Moon, and guides demonstrating how the stacking algorithm dramatically sharpens noisy astrophotography footage.
https://ancient-skies.org/
Ancient-Skies is a collaborative scientific knowledgebase dedicated to documenting how human cultures across history have understood and represented the night sky. The project, launched around the International Year of Astronomy 2009, aims to gather and verify information from primary sources, making cultural astronomy accessible to both the general public and researchers worldwide.
https://observers.org/
The SF Bay Area Astronomy Connection (TAC) is an informal network for amateur astronomers across the greater San Francisco Bay Area, connecting observers without the formality of dues, officers, or bylaws. The site features an extensive list of observing sites throughout the region, curated observing lists, equipment guides, and resources for both beginners and seasoned stargazers.
http://kusastro.kyoto-u.ac.jp/vsnet
VSNET is an international mailing list network based at Kyoto University dedicated to real-time alerts and collaborative observation of variable stars, cataclysmic variables, novae, supernovae, and X-ray binaries. Hosting decades of light curve archives from AFOEV observations and ongoing amateur-professional collaboration campaigns, it serves as a serious citizen science hub for variable star astronomy worldwide.
https://starchild.gsfc.nasa.gov/docs/StarChild/StarChild.html
StarChild is NASA's Goddard Space Flight Center educational resource designed to introduce young astronomers ages 5-13 to the solar system, the Milky Way, and the broader universe. Organized into two skill levels, the site covers topics from comets and black holes to galaxies and space terminology, making complex astronomical concepts accessible to children.
http://hnsky.org/
Home of ASTAP and HNSKY, two free astronomy programs offering image stacking, plate solving, and a full-featured planetarium for amateur astronomers and astrophotographers. The creator also shares their own astrophotography images and equipment details, making this a practical hub for both software users and sky enthusiasts.
http://ccas.us/
The Chester County Astronomical Society (CCAS) is a Pennsylvania-based non-profit bringing together amateur astronomers through monthly meetings, observing sessions, and public star parties for schools and civic groups. The site features an events calendar, member photography, planetarium show schedules at West Chester University, and resources for anyone interested in exploring the night sky.