Great fun, nice gridding.

Multiple correct solutions. :-( "Mars" can be subbed out for Milky Way or Galaxy without messing up other rows.

Would not accept astronomical features for the space group. 😠

It's my first ever attempt - Big fan of Only Connect. I'm a science teacher and plan to make a few of these to use as lesson resources. Thanks for the feedback!

Credit to you MrBowstead for using innovative teaching methods. Enjoyment is a key part of learning. If you have mixed ability students it would be possible to set different levels of difficulty using the grid "tricks". For example a base level might have a solution where each item can only belong to one group. The next level would add crossovers where an item(s) could fit in more than one group but crucially there is only a single possible solution. The next level could add red herrings for example items that appear to be in a group but it is actually a "false" group. Maybe it would be unfair to be devious - you will be a far better judge of that than me. Trying to pre-empt all possible correct answers can be tricky but I guess this would not be a problem if the grid is not computerised and "programmed" to match key character strings as used on this site.

Thanks