r/space vs r/Astronomy

Side-by-side using public descriptions, members, growth and rule titles from SubMouse. Missing fields show as n/a. Adult communities are excluded.

Swap sides New comparison Related to r/space Related to r/Astronomy

Space news desk vs amateur astronomy hobby

r/space shares informative content on astrophysics, cosmology, space exploration, planetary science and astrobiology. r/Astronomy covers the amateur hobby and scientific study of celestial objects—pictures, identification, questions and telescope help show up in its collected rule titles.

Both have SubMouse pages (space about 28.0M, rank #16; Astronomy about 3.2M, rank #333). Activity samples are similar in tempo (roughly 27 vs 25 posts/day) but differ in mix: space leans links/text with Sunday-only images per its titles; Astronomy’s sample is more image-led.

Collected titles keep sensationalism and social links out of space, and structure Astronomy around pictures/videos, object ID, questions and telescope help. Bring mission and cosmology news to space; bring backyard observing and gear questions to Astronomy.

r/space: space/cosmology news; no sensationalism; images only Sunday UTC (collected titles).
r/Astronomy: amateur observing; pictures, ID, questions, telescope help (collected titles).
News vs hobby practice. Both have full SubMouse community pages.

Written comparison based on public descriptions and rule titles · updated 2026-11-06.

r/space

/r/space: news, articles and discussion

Share & discuss informative content on: * Astrophysics * Cosmology * Space Exploration * Planetary Science * Astrobiology

Members: 28M
7-day growth: +2.7K
Posts/day: 26.9
Directory rank: #16
Created: Jan 26, 2008
Submissions: Text or links

Sample mix: links 38%, text posts 29%, images 21%

Topics: News, Science, Space & Astronomy

Rule titles (short names we collected)

Submissions must be related to Space/Cosmology
No sensationalist/misleading/unscientific content or titles
No spam/blogspam/paywalled/pirated content
No petitions/surveys/crowdfunding
No social media links
No duplicate or re-hosted content
Images are only allowed on Sunday UTC
No low-effort or meme images are permitted at any time.
If an image is not OC you must give credit to the original photographer.
No low-effort/meme/joke/troll/insult comments
No unscientific or anti-scientific comments
Straightforward questions belong in the Space Questions Thread

Open r/space on SubMouse

r/Astronomy

Astronomy

The amateur hobby of humanity since the dawn of time and scientific study of celestial objects.

Members: 3.2M
7-day growth: +1.5K
Posts/day: 25.2
Directory rank: #333
Created: Mar 28, 2008
Submissions: Text or links

Sample mix: images 48%, text posts 28%, galleries 11%

Topics: Space & Astronomy

Rule titles (short names we collected)

Pictures & Videos
Object Identification
Questions
Telescope Help
Content
Behavior
Sources
Repetition & Relevance
Misinformation & Pseudoscience
Minimum Karma
Post Types

Open r/Astronomy on SubMouse

Supported differences

Aspect	r/space	r/Astronomy
Public focus (from each community’s public description)	Share & discuss informative content on: * Astrophysics * Cosmology * Space Exploration * Planetary Science * Astrobiology	The amateur hobby of humanity since the dawn of time and scientific study of celestial objects.
Size r/space is larger in our directory (about 8.9×).	28M members	3.2M members
Posting activity (our sample)	26.9/day	25.2/day
Common post types in our sample	links 38%, text posts 29%, images 21%	images 48%, text posts 28%, galleries 11%
Topic tags on SubMouse	News, Science, Space & Astronomy	Space & Astronomy
Selected rule titles (short names we collected)	Submissions must be related to Space/Cosmology; No sensationalist/misleading/unscientific content or titles; No spam/blogspam/paywalled/pirated content; No petitions/surveys/crowdfunding; No social media links	Pictures & Videos; Object Identification; Questions; Telescope Help; Content

What they share

Shared SubMouse topics: Space & Astronomy

Rules and tone we can verify

space: must be related to Space/Cosmology; no sensationalist/unscientific titles; no spam/paywalls; no petitions/surveys; no social media links; no duplicates/rehosts; Images only on Sunday UTC. Astronomy collected short titles group Pictures & Videos; Object Identification; Questions; Telescope Help; Content; Behavior; Sources.

Where this comparison comes from

Public descriptions and member counts from SubMouse’s safe-for-work directory. Short rule titles and activity samples collected for both. Short titles only.

Members and public descriptions come from SubMouse's safe-for-work directory (as of 2026-11-02 UTC); 7-day growth measured from 2026-10-26. Posts/day and post-type mixes appear when we have an activity sample. Rule lines are short titles, not the full sidebar. Directory rank is listing order — communities outside the current Top 100 open in the info tool instead of a full community page.