1. Chris Hadfield.
He's not in space anymore, but Chris Hadfield is still tweeting some amazing images of Earth and the cosmos. Follow him as he travels around the world sharing his experience of being an astronaut.
2. Tiktaalik roseae, a fossil fish.
It's a 375 million year old fossil fish from the Canadian Arctic. If that's not enough for you, Tiktaalik roseae is also known as the "fishapod" and sheds light on when fish first ventured onto land.
It was first described in 2006 but its only now that the researchers have unearthed and described the back half of the specimen. So expect to hear more about our fishy evolutionary roots in the near future – straight from the fossil's mouth.
3. NASA's Voyager 2.
Voyager 2 was launched first but in terms of getting out of the solar system is trailing behind it's sister craft, Voyager 1, which entered interstellar space in 2012. This account tweets somewhat cryptic and occasionally weirdly poetic status updates for both probes. Also follow @NASAVoyager for less frequent but more human-sounding mission updates.
4. Neil deGrasse Tyson.
When he's not busy being presenting the reboot of everyone's favourite popular science TV show or being Director of the Hayden Planetarium in New York, deGrasse Tyson tweets astronomy and astrophysics tidbits.
5. Sci Curious.
Scicurious is the codename of neuroscience postdoc turned science writer Bethany Brookshire. She writes and tweets about the "good, bad and weird" in neuroscience and provides a great, honest insight into being a scientist, too. Her recent post on how to get out of academia hit a nerve with a lot of people and is a must-read if you're a PhD student not sure what to do next.
6. The SETI Institute.
The SETI Institute are searching for extraterrestrial intelligence. But they also tweet news of new alien planets and astrobiology findings that are relevant to what they call the "most profound search in human history".
And of course, if they ever find anything, you'll want to be the first to know.
If you're not convinced we're doing enough in the search for extraterrestrials, you'll enjoy the (spoof) WETI Institute account. Instead of searching for ET, they are waiting. As the put it: "All good extraterrestrials come to those who wait."
8. Carl Zimmer.
Science writer extraordinaire Carl Zimmer blogs on mainly on life sciences at The Loom, but his tweets cover a wide variety of news and interesting pieces from the wider science world.
9. Phil Plait, aka Bad Astronomer.
Phil Plait blogs at Slate on astronomy and bad science. Follow him for a bit more of an in-depth take on the latest astronomy news (and some very pretty space pictures).
10. N165, a rock on Mars.
Sure, you should also be following Nasa's official Curiosity Rover account. But if you want a bit of a more irreverent look at what the rover is doing on the surface of Mars you could do worse than follow N165.
Also known as Coronation, the Martian rock shot to fame when it became the first rock the Curiosity rover shot with its onboard laser. Now it shares news and updates from Curiosity's travels.
11. Virginia Hughes.
Virginia Hughes is a science journalist and author of the Only Human blog at National Geographic. She writes and tweets on neuroscience, genetics, behavior, and medicine.
12. Brian Switek.
If you loved dinosaurs as a kid, follow Brian Switek to find out what scientists have discovered about all of your favourites since then. If you were a fan of the Brontosaurus, well, I hate to break it to you, but...
13. Deborah Blum.
Pulitzer Prize winning Deborah Blum is your go to science writer for all things poisonous. Her Wired blog, Elemental, is probably the most accessible chemistry blog on the web. In her tweets you'll find more of the same, plus well-informed thoughts on toxic stories from elsewhere.
14. Tim Berners-Lee.
You wouldn't even be on Twitter if it wasn't for Tim Berners-Lee inventing the World Wide Web, so this is the least you can do. Now he is director of web standards organisation the World Wide Web Consortium, and founder of the World Wide Web Foundation, a non-profit devoted to spreading the web.
15. Rebecca Skloot.
Rebecca Skloot is author of The Immortal Life of Henrietta Lacks, a bestseller that tells the story of how one woman's cancer cells spawned a whole field of scientific inquiry.
16. Jennifer Ouellette.
Jennifer Ouellette aka JenLucPiquant is the author of Cocktail Party Physics at Scientific American and tweets physics, pop culture and where the two meet. Catch her weekly physics links to see what you missed during the week.
17. ESA's Rosetta spacecraft.
The European Space Agency's Rosetta spacecraft is due to wake from its deep space hibernation any moment now. When it does it'll be making its way over to a comet and, if all goes to plan, should arrive there by August this year.
18. Henry Reich, aka minutephysics.
Henry Reich's YouTube channel MinutePhysics has some great animated explanations of concepts from physics.
If you got this far on Twitter without following Nasa I'm not quite sure how to help you. Go and do it immediately for a mix of amazing space images and cool new discoveries from the space agencies many telescopes and missions.
For more of a focus on Saturn you'll want to make sure you're also following the Cassini spacecraft, which is currently in orbit around the planet and tweeting a lot of photos it takes.
21. Carolyn Porco.
22. Ed Yong.
Ed Yong is author of the blog Not Exactly Rocket Science at National Geographic covering what he calls the "wow beat". He tweets a whole load of great science stories you should be reading, and compiles them into a weekly round up so you can be sure you haven't missed anything.
23. Roger Highfield.
Once editor of New Scientist, Roger Highfield is now an executive at the Science Museum and, occasionally, a columnist for The Telegraph. He tweets quirky science news from all over the place, as well as updates from the museum.
24. ESA CAVES.
Before ESA astronauts can go to space, they have to complete a whole different kind of mission – spending two weeks in a cave. The missions simulate the isolation of space and help build team-working skills.
This account tweets info and pictures from those caves. And when a mission isn't underway, it shares some pretty spectacular images and stories about Earth and space, too.
25. Maryn McKenna.
Maryn McKenna is a science journalist and author who writes on antibiotic resistance among other things. Follow for occasionally scary but always necessary stories on how we're all going to die horribly very soon.