r/cosmology↗
**/r/cosmology** - a community for questions, discussions, and articles about cosmology.
144k subscribers63 posts / mo in Sep 2026 (incl. ~8% by known bots)51 authors / mosince 2009
r/cosmology has 144k members (+20% over the last 12 months). It gets about 63 posts a month from 51 people. Top topics: Big Bang Theory, Dark Matter Mysteries and Galaxy Exploration.
When to post on r/cosmology
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How r/cosmology has grown
Subscriber growth
Subscribers over time
Monthly activity
Posts, comments and authors per month
Topics and brands on r/cosmology
Top topics
Share of the subreddit's posts
- Big Bang Theory5.2%
- Dark Matter Mysteries1.9%
- Galaxy Exploration1.3%
- James Webb Galaxies Cluster0.7%
- Interstellar Objects & Stars0.7%
Brands people mention
Most-mentioned brands and sites, last 12 months
- arXiv.org e-Print archive
- Reddit Help
- Doi
- Zenodo
- NASA
Everything else about r/cosmology
Posting rules and account requirements, how often posts get removed, who writes here (age, gender, countries), what people ask for, how they talk, and related subreddits — all in the full report.
Posts and activity for Sep 2026. Members from Reddit's subscriber counts. Read from the same data the app runs on. Our research