Astronomy & Space
396 sites
http://astronautica.com/owds.html
Other Worlds, Distant Suns, maintained by Garber Astronautics, is a detailed catalog of extrasolar planets featuring individual pages for dozens of star systems like 51 Pegasi, Gliese 876, and upsilon Andromedae. The site stands out for its interactive VRML 3D visualizations of extrasolar systems, observing guides for both celestial hemispheres, and curated links to leading researchers like Geoff Marcy and Jean Schneider.
http://burtleburtle.net/bob/scifi/dyson.html
Bob's detailed technical exploration of Dyson swarms and torus-shaped satellite constellations covers the mathematics and orbital mechanics behind capturing a star's energy output. The page features interactive JavaScript simulations letting visitors visualize these megastructure concepts from within the swarm itself, alongside references to real-world applications like SpaceX's Starlink constellation.
https://soho.nascom.nasa.gov/data/realtime/realtime-update.html
NASA's SOHO (Solar and Heliospheric Observatory) mission serves up the very latest real-time solar images captured by instruments including EIT, LASCO, and SDO/HMI, updated continuously from the spacecraft. Visitors can explore the sun in multiple wavelengths and coronagraph views, making this an invaluable resource for solar observers, space weather enthusiasts, and researchers alike.
http://celestrak.org/
CelesTrak, maintained by T.S. Kelso, is a premier resource for satellite tracking data including NORAD GP element sets, two-line element (TLE) files, and orbital environment tools used by the global space community. Now operating as a 501(c)(3) non-profit, it offers visualization tools, SOCRATES conjunction analysis, documentation, and special event coverage including debris events and rocket body reentries.
https://skymarvels.com/
SkyMarvels is an astronomy education site that guides visitors through the night sky and solar system using interactive animations, videos, and the free 3-D simulation software Celestia. Covering everything from individual planets and moons to deep-sky objects and the scale of the cosmos, the site offers a genuinely immersive experience suitable for beginners and enthusiasts alike.
https://minnesotasky.tripod.com/
The Steele County Astronomical Society (SCAS) is an Owatonna, Minnesota-based astronomy club affiliated with the Astronomical League, organizing events like Messier Marathons, park viewing nights, and observatory tours. The site lists the club's annual schedule, membership information, and links to the Owatonna Clear Dark Sky Report for planning observation sessions.