NEOCC Riddles

On this page, the NEOCC provides problems (we call them 'riddles') related to the observation of NEOs, their dynamics and their characterisation. In irregular time intervals, we will be publishing a new riddle and invite you to think about it and respond before a given deadline. We will be publishing the results and the names of the people or teams that successfully solved the riddle after that deadline.

Please, send your responses before the proposed deadline to the following e-mail:, and use as subject of your e-mail: "Riddle #N - solution", where N is number of the riddle. Moreover, please let us know if you would prefer not to have your name included in the list of correct replies.


# Riddle Publication date Deadline Download
6 Earth and Mars Impactor. 05-11-2020 25-11-2020 Riddle  |  Answer
5 Scanning the sky like a fly. 05-10-2020 25-10-2020 Riddle  | Answer
4 Find an NEO! 04-09-2020 25-09-2020 Riddle  |  Answer
3 A visitor from outer space. 05-08-2020 25-08-2020 Riddle  | Answer
2 The size of an asteroid thrown at Earth by Planet X. 30-06-2020 25-07-2020 Riddle  |  Answer
1 An NEO with a peculiar orbit. 04-06-2020 25-06-2020 Riddle  |  Answer