Do you think you've got decent science knowledge? It's time to put your gray matter to the test with our weekly, free science crossword puzzle.

We've spent hours carefully writing our puzzles to make sure they are challenging but accessible to people of all ages and scientific backgrounds, with answers ranging from unusual animals and ancient rulers, to fundamental theories and Nobel Prize-winning scientists. Don't expect it to be easy, but it will be fun!

All you have to do to play is register once and then you should be logged in for next time, and if you need a hint tap the question mark next to the clue to reveal a letter.

Be sure to share this with your friends, and if you want more fun and games, you can also try out one of our amazing science quizzes on more than 50 different topics.

Note: Our crosswords are currently best experienced on desktop.

Previous science crosswords

Want to try your luck with our previous crossword puzzles? The most recent ones can be found below, but you can access the full list of science crosswords here.

—#53: Ancient supercontinent — 11 across

—#52: The moon's other name — 2 down

—#51: Largest rodent on Earth — 4 down

—#50: Longest-serving president in US history — 1 across

—#49: 'Short' tempered French emperor — 13 across