Space and astronomy subreddits
We found 66 active space and astronomy subreddits: communities with at least one new post a day on average in September 2026, ranked by members. The largest is r/space with 28M members. The busiest is r/telescopes, with 797 posts last month. In 6 of the 31 we could measure, a brand-new account's post usually stays up: they remove 17% or fewer of posts from accounts under a week old.
Data for 66 communitiesDownload CSV
Filter it by your account age and karma, the audience you want and the best time to post.
- r/space28M members
- r/telescopes797 posts in September 2026
- r/SpellcasterReviews+506% members in 12 months
- r/spacex100% of posts get a reply
All active space and astronomy subreddits, by members
| # | Subreddit | Members | Posts / month | Member growth, 12 mo | Median author age | Women | Posts with a reply | New-account posts removed | Links |
|---|---|---|---|---|---|---|---|---|---|
| 1 | r/space↗Share & discuss informative content on: * Astrophysics * Cosmology * Space Exploration * Planetary Science * Astrobiology | 28M | 762 | +1% | 31 | 15% | 49% | 86% | Yes |
| 2 | r/nasa↗r/NASA is for anything related to the National Aeronautics and Space Administration; the latest news, events, current and future missions, and more. | 5.88M | 246 | +1% | 32 | 18% | 74% | 99% | Yes |
| 3 | r/spaceporn↗SpacePorn is a subreddit devoted to beautiful space images 🚀🌌. As long as the focus of the image is related to space in some way, it is allowed. This includes photographs, composites, photoshops, si | 4.32M | 502 | +5% | 32 | 17% | 77% | Min. age/karma | Yes |
| 4 | r/spacex↗Welcome to r/SpaceX, the premier SpaceX discussion community and the largest fan-run board on the American aerospace company SpaceX. We recommend using r/SpaceX with Old Reddit. This board is not an | 3.7M | 150 | +1% | 30 | 10% | 100% | 100% | Yes |
| 5 | r/Astronomy↗The amateur hobby of humanity since the dawn of time and scientific study of celestial objects. | 3.15M | 769 | +4% | 31 | 19% | 59% | 59% | Yes |
| 6 | r/ISRO↗For anything related to Indian space agency we love but hardly know. | 455K | 182 | +2% | 23 | 16% | 49% | 100% | Yes |
| 7 | r/SpaceXLounge↗Welcome to r/SpaceXLounge, the sister subreddit to r/SpaceX, and a place for relaxed and laid-back discussion. We recommend Old Reddit with r/SpaceXLounge. This subreddit is not an official outlet for | 385K | 181 | +2% | 31 | 11% | 69% | 89% | Yes |
| 8 | r/spaceflight↗A subreddit for articles, images, videos and discussion about spaceflight. | 316K | 138 | +7% | 35 | 12% | 53% | 85% | Yes |
| 9 | r/telescopes↗new-account friendlyThe home to all amateur astronomers & telescopes! Feel free to discuss anything astronomical here, from what sort of telescope you should get, stargazing tips and tricks, to how to use that scope of y | 269K | 797 | +20% | 32 | 16% | 91% | 13% | Yes |
| 10 | r/askastronomy↗For your astronomy-related questions and content! | 185K | 396 | +39% | 35 | 17% | 83% | 19% | Yes |
| 11 | r/astrophysics↗The branch of astronomy concerned with the physical nature of stars and other celestial bodies, and the application of the laws and theories of physics to the interpretation of astronomical observatio | 173K | 147 | +33% | 33 | 17% | 57% | Min. age/karma | Yes |
| 12 | r/Stargazing↗new-account friendlyJoin in the Gaze. | 155K | 474 | +31% | 32 | 36% | 52% | 12% | Yes |
| 13 | r/cosmology↗**/r/cosmology** - a community for questions, discussions, and articles about cosmology. | 144K | 63 | +20% | 34 | 14% | 60% | Min. age/karma | Yes |
| 14 | r/moon↗Photos and discussion about the Earth's moon. | 140K | 645 | +22% | 33 | 41% | 51% | Min. age/karma | Yes |
| 15 | r/jameswebb↗Welcome to /r/JamesWebb, the subreddit for NASA's James Webb Space Telescope. Launched on December 25th, 2021, the James Webb Space Telescope or JWST succeeds the highly successful Hubble telescope a | 131K | 67 | +6% | 34 | 13% | 58% | – | Yes |
| 16 | r/aerospace↗A place to discuss relevant topics in civil and military aviation, space exploration, and news relevant and interesting to those with a passion for all things flying. | 130K | 252 | +16% | 28 | 15% | 63% | 93% | Yes |
| 17 | r/SpaceXMasterrace↗A subreddit for the great Space X masterrace to discuss the words of EloN and his Glorious company Space X. SMART discussion about other rockets is also ok | 110K | 216 | +14% | 31 | 11% | 76% | Min. age/karma | Yes |
| 18 | r/Mars↗Articles and discussion about the planet Mars. What's going on? What's going on? We're going dark until further notice to protest reddit's new policies. Read more here (archived snap of the post): | 100K | 173 | +29% | 36 | 13% | 49% | Min. age/karma | Yes |
| 19 | r/universe↗The Universe is a forum for sharing and discussion of Astronomy, Astrophotography, Astrophysics & Cosmology. | 80K | 238 | – | 36 | 14% | 44% | 82% | Yes |
| 20 | r/SpaceflightSimulator↗new-account friendlyWelcome to the official subreddit for Spaceflight Simulator, a game about exploring our local space with rockets you build! | 77K | 469 | +26% | 18 | 12% | 92% | 3% | Yes |
| 21 | r/eliteexplorers↗With four hundred billion stars, explorers play an important role in Elite: Dangerous. This is a place where we can share useful information, noteworthy discoveries and opportunities for collaboration | 71K | 80 | +7% | 31 | 8% | 81% | – | Yes |
| 22 | r/meteorites↗r/meteorites is a scientific community focused on discussing and identifying meteorites. Identification posts are welcome, but MUST be posted in the monthly "Suspect Meteorite Identification" thread | 71K | 84 | +38% | 36 | 18% | 82% | 25% | Yes |
| 23 | r/sun↗A community dedicated to the Sun, the star at the center of our solar system. Share solar photography, discuss sunspots, flares, eclipses, and solar science, or simply appreciate the power and beauty | 68K | 176 | +49% | 32 | 40% | 97% | 18% | Yes |
| 24 | r/AskAstrophotography↗new-account friendlyA place to ask questions & help others with anything related to astrophotography. https://discord.gg/K26PDTuqnG | 67K | 270 | +31% | 31 | 12% | 92% | 7% | No |
| 25 | r/ArtemisProgram↗This subreddit is for discussion of NASA's Artemis Program. | 65K | 49 | +410% | 35 | 23% | 74% | – | Yes |
| 26 | r/SpaceUnfiltered↗A free space to share stunning views of the cosmos. From NASA shots to personal astrophotography, everything space is welcome. Please add source link before posting. Thank you. . . 👉 Note: This subr | 55K | 257 | +185% | 40 | 12% | 36% | – | Yes |
| 27 | r/BlueOrigin↗A subreddit to discuss the space company Blue Origin, which makes the New Glenn and New Shepard rockets | 53K | 137 | +23% | 32 | 14% | 81% | 55% | Yes |
| 28 | r/spaceengine↗r/spaceengine is an unofficial community group that brings together enthusiasts of SpaceEngine, astronomy, and all those interested in space exploration. | 50K | 225 | +16% | 24 | 12% | 68% | 44% | Yes |
| 29 | r/AstronomyMemes↗new-account friendlyThe only spot in the galaxy for memes about Space, Astrophotography, Telescopes, Spaceflight, and much more! | 43K | 90 | +50% | 27 | 19% | 76% | 15% | Yes |
| 30 | r/RocketLab↗Fan-run subreddit for Rocket Lab, the end-to-end space company | 42K | 56 | +21% | 32 | 9% | 61% | 23% | Yes |
Show all 66 subreddits
| # | Subreddit | Members | Posts / month | Member growth, 12 mo | Median author age | Women | Posts with a reply | New-account posts removed | Links |
|---|---|---|---|---|---|---|---|---|---|
| 31 | r/SpellcasterReviews↗Reviews of spellcasters, psychics and tarot readers. | 41K | 407 | +506% | 27 | 82% | 69% | 100% | Yes |
| 32 | r/darksky↗Dedicated to finding, sharing, and preserving the best places to see the stars. Feel free to share stories, photos, and anything else related to observing the night's sky, including stargazing, dark s | 41K | 40 | +18% | 35 | 27% | 52% | – | Yes |
| 33 | r/Spaceexploration↗r/SpaceExploration is a subreddit all about space travel (NASA, Roscosmos, SpaceX, ULA, Boeing, Rocket Lab, etc.). Further topics include upcoming launches, science missions, engineering, and more! | 41K | 112 | +18% | 35 | 12% | 100% | – | Yes |
| 34 | r/ItsAlwaysPleiades↗For those inquiring about astrophotos that are always the Pleiades, also known as the Seven Sisters or Messier 45. It's made up of several hundred stars, including six or seven that are visible to the | 40K | 37 | +27% | 33 | 31% | – | – | Yes |
| 35 | r/esa↗r/esa provides the latest news, events, mission facts and a platform for discussion about ESA, the European Space Agency, and its projects. Please keep your posts related to the subject of space and/ | 40K | 73 | +22% | 27 | 18% | 70% | – | Yes |
| 36 | r/curiosityrover↗A subreddit for scientific discussion of the Curiosity Rover and Mars Science Laboratory. | 39K | 39 | +6% | 33 | 13% | 20% | – | Yes |
| 37 | r/amateursatellites↗A subreddit dedicated to artificial satellites that the everyday folk can interact with, but topics relating to all kinds of man-made satellites are welcome | 39K | 137 | +63% | 32 | 9% | 63% | – | Yes |
| 38 | r/amateurastronomy↗News, info, tips, ideas and advice about amateur astronomy. | 38K | 283 | +86% | 34 | 18% | 29% | 18% | Yes |
| 39 | r/seestar↗new-account friendlyShare your images taken with the Seestar smart telescopes, and tips for image processing and much more | 37K | 650 | +46% | 38 | 13% | 100% | 7% | Yes |
| 40 | r/solareclipse↗A place to share information that helps fellow redditors optimize their experience of a Total Solar Eclipse (TSE). | 30K | 77 | +36% | 34 | 36% | 66% | – | Yes |
| 41 | r/SpaceVideos↗For documentaries, time-lapses, simulations and other videos related to the universe. Sit back and relax, or learn something new! | 29K | 38 | +49% | 35 | 13% | – | – | Yes |
| 42 | r/ISS↗A subreddit dedicated to the International Space Station. | 27K | 66 | +98% | 35 | 17% | 34% | – | Yes |
| 43 | r/SpaceInvestorsDaily↗This community is for space investors & lovers of space technologies. All levels of knowledge & interest are welcome, from seasoned investors to space enthusiasts beginning to explore space. Coverin | 27K | 210 | +209% | 35 | 10% | 54% | – | Yes |
| 44 | r/MilkyWayPlayground↗Learn science by playing games on iOS 👉 bit.ly/3InQcPL | 26K | 42 | – | 40 | 11% | – | – | Yes |
| 45 | r/Stars↗Stars | 22K | 76 | +32% | 28 | 29% | 57% | 24% | Yes |
| 46 | r/satellites↗Dedicated to Earth-orbiting satellites and the satellite and space services industries. | 21K | 106 | +71% | 34 | 13% | 38% | 44% | Yes |
| 47 | r/IntuitiveMachines↗Intuitive Machines is a space infrastructure and services company founded in 2013 and focused on enabling sustained infrastructure and human activity beyond Earth. The Company build spacecraft, connec | 20K | 42 | +19% | 32 | 10% | 91% | – | Yes |
| 48 | r/MarsSociety↗The Mars Society is the world's largest and most influential space advocacy organization dedicated to the human exploration and settlement of the planet Mars. Established by Dr. Robert Zubrin and othe | 19K | 411 | +30% | 40 | 12% | 23% | – | Yes |
| 49 | r/SolarMax↗Welcome to r/SolarMax, a sub dedicated to all things solar and space weather. Join us as we journey through the solar maximum of Solar Cycle 25. For Real Time Updates and Analysis Check Out The Sola | 18K | 30 | +30% | 38 | 37% | – | – | Yes |
| 50 | r/RealSolarSystem↗The official subreddit for the Real Solar System, Realism Overhaul and RP-0 mods for Kerbal Space Program. | 18K | 88 | +27% | 23 | 11% | 75% | – | Yes |
| 51 | r/spaceshuttle↗Subreddit for all things related to the retired NASA Space Shuttle program. | 17K | 54 | – | 41 | 10% | 83% | – | Yes |
| 52 | r/exoplanets↗This is where you can discuss extrasolar planets, commonly known as exoplanets, and related sciences including exoplanet detection methods, exoplanet signature spectroscopy, astrobiology, and more. Re | 16K | 53 | +23% | 34 | 14% | 100% | Min. age/karma | Yes |
| 53 | r/blackholes↗A place to post and ask questions about the phenomena known as Black Holes | 15K | 49 | – | 35 | 14% | 67% | Min. age/karma | Yes |
| 54 | r/NorthropGrumman↗News & discussion about Northrop Grumman | 15K | 37 | +13% | 30 | 20% | – | – | Yes |
| 55 | r/remotesensing↗For all things related to Remote Sensing of the planet from space or from aircraft/UAVs. History, raw data, beautiful images, news, software, tutorials, questions, it's all welcome. | 15K | 77 | +24% | 29 | 22% | 44% | – | Yes |
| 56 | r/spacequestions↗SpaceQuestions is a subreddit for asking questions about astronomy, rocketry, astrophysics and cosmology. We welcome everyone to post questions to satisfy their curiosity and further their scientific | 12K | 67 | +42% | 37 | 14% | 81% | – | No |
| 57 | r/milkyway↗A place to share Milky Way and other space related content. From Earth-bound discoveries to mind-bending images. -/- We'd like this sub to lean more toward education/information than other space subre | 11K | 66 | – | 33 | 26% | 43% | – | Yes |
| 58 | r/legoRockets↗A community for all things Lego NASA/ESA/ROSCOSMOS (and all others space agencies around the world)! Brickbuilt Rockets, spacecraft, shuttles, rovers, and probes from the very beginning of the space a | 8.2K | 53 | +24% | 27 | 11% | 69% | – | Yes |
| 59 | r/EUSpace↗All contents relevant to European Union and member states Space Agencies and industries. News, events, information, pictures, videos, memes. | 7.9K | 51 | – | 34 | 10% | – | – | Yes |
| 60 | r/rocketlaunches↗r/rocketlaunches is a community for tracking global rocket launches, mission updates, and spaceflight analysis. Users share schedules, livestreams, payload details, and post-launch data across commerc | 7.6K | 31 | +40% | 32 | 13% | – | – | Yes |
| 61 | r/plasmacosmology↗Plasma Cosmology is the most scientific paradigm of astronomy and astrophysics for those who refuse to substitute fairy tales for facts. | 7.1K | 34 | +21% | 36 | 13% | 54% | – | Yes |
| 62 | r/DWARFLAB↗A place to post pictures and discuss the DWARFLAB telescope! NOT affiliated in any way with the actual company. | 7.1K | 348 | +240% | 41 | 9% | 58% | – | Yes |
| 63 | r/SpacePolicy↗/r/SpacePolicy, a community dedicated to the discussion and debate of outer space policy, legislation, and law. | 6.9K | 68 | +19% | 32 | 16% | 4% | – | Yes |
| 64 | r/askspace↗A community for asking and answering space, astronomy and spaceflight related questions. | 5.3K | 49 | – | 39 | 11% | 69% | – | Yes |
| 65 | r/constellations↗The sub to classify and connect with all astronomers about IAU recognized and personally determined constellations! Find a picture in the sky, photograph it, let us know about it! | 3.6K | 31 | – | 25 | 40% | – | – | Yes |
| 66 | r/space2030↗Predictions of space and space related technologies, systems and projects that will become operational and widely used in the 2030s. In addition to lots of possibilities for SpaceX F9/CD/FH and Stars | 2.4K | 81 | – | 41 | 9% | 52% | – | Yes |
Looking for a ranking by size and growth? Top space and astronomy subreddits by tier.
How this list is built
Subreddits are grouped into topics by what their posts are about; this list holds the space and astronomy group. We include subreddits that are safe for work and had at least 30 new posts in September 2026, about one a day.
Members is Reddit's subscriber count; growth compares it with a year earlier. Posts with a reply is the share of posts that got at least one comment over the last three months. Median author age and women are estimated from what authors say about themselves, and shown only when enough of them did. New-account posts removed is the share of posts from accounts younger than 7 days that were removed; communities at or below 17% are marked new-account friendly. Min. age/karma means the subreddit asks for a minimum account age or karma before you can post.
The list is rebuilt every month from public Reddit posts and comments. Data and CSV are free to reuse under CC BY 4.0 with a link to this page.
Space and astronomy subreddits: common questions
What is the biggest space and astronomy subreddit?
r/space, with 28M members in September 2026. Next are r/nasa (5.88M) and r/spaceporn (4.32M).
Which space and astronomy subreddits are the most active?
By posts in September 2026: r/telescopes (797 posts), r/Astronomy (769 posts) and r/space (762 posts).
Which space and astronomy subreddits can a new account post in?
r/telescopes (13% of new-account posts removed), r/Stargazing (12% of new-account posts removed) and r/SpaceflightSimulator (3% of new-account posts removed). They ask for no minimum karma or account age, and most posts from accounts under a week old stay up.
How often is this list updated?
Every month, when we rebuild our subreddit data. This version uses data for September 2026. Member counts come from Reddit; activity, removals and who writes come from public Reddit posts and comments.
Find the subreddits that fit your post
This list is the same for everyone. Find Subs narrows it to communities your account can post in, where your audience writes, and tells you when to post.