This post is not sponsored by Bluesky. All opinions herein are those of the author and do not necessarily reflect the opinions of the Astrobites collaboration as a whole.
Networking is essential for a career in astronomy. The advent of social media has helped democratize access to information about jobs, fellowships, and programs, as well as connections with senior faculty and staff. Twitter was a major component of the online astronomy community until leadership changes led to a decline in users. This fracture in the community is a particularly large problem for early career researchers and researchers from non-traditional backgrounds who relied on the online community for advice and opportunities.
Several competitors to Twitter have sprung up, including Meta’s Threads and Mastodon. But none have taken off as much in the astronomy community as Bluesky. Bluesky was originally a project started by Twitter, but went independent in 2021 and launched publicly in 2022. The site is built on a completely open-source social media protocol (ATProtocol), a distributed system with a lot of good features to protect users and their data. Bluesky doesn’t currently have advertising and hopes to avoid introducing it, and they don’t use user data for generative AI training. The platform has grown massively since November 2024, doubling its user base. As of January 2025, it has more than 27 million registered users, around 10 million of whom are active monthly.
Bluesky works nearly identically to Twitter, with individual profiles, short posts, the ability to upload media, and use hashtags. One unique feature is the ability to create specialized feeds. These feeds have some backend code that collates together posts around a certain topic into one channel you can subscribe to. Astronomy has one main feed as well as about a dozen (as of Jan. 2025) specialized feeds for subfields like planetary science and radio astronomy. Each feed is identified by a unique emoji or hashtag; users sign up to contribute to a feed and only their posts containing that emoji get added to the feed. The main feed, for example, uses the telescope emoji [🔭]. There’s also a general scientific research feed, characterized by a test tube emoji, that is fairly active.

Joining the Astronomy feeds as a contributor is really simple; users can join with a quick tweet at a bot account that will process their request. There is a code of conduct, and the feeds are generally very friendly. If you want a fun little project to work on, creating bots and feeds on Bluesky is free and reasonably straightforward, with plenty of boilerplate code to work off of. You can learn more about the Astronomy feeds on their GitHub.

Also unique to Bluesky are starter packs, which recommend users and feeds. Astrobites has a starter pack with links to follow our authors and the main Astronomy feed. These starter packs are a great way to find interesting people to follow and can make the transition from Twitter easier.
The astronomy community on Bluesky is small but growing, and many users are hopeful we can build a new online space for our field. Many major astronomy organizations and telescope programs are actively posting on the platform, including AAS, ESA, ESO, and STSci. The platform Altmetric is supported on Bluesky, which allows users to track posts and mentions of their research posted to the platform.
Astrobites no longer posts actively on Twitter, but you can catch our daily summaries on Bluesky @astrobites.bsky.social and on the Astronomy feed. Want to get in on the fun? Dr. Emily Hunt, who runs the Astronomy feeds, made a really excellent Astronomy-focused starter guide you can find [here].
Editor: Emily Hunt, Samantha Wong
Featured Image Credit: Eric Bailey, G. De Marchi (STScI and Univ. of Florence, Italy) and F. Paresce (STScI)/NASA, ESA.
This is excellent news as l’ve seen a drop-off of users on the massive profit and political-culture war ilk. Thank you.