The most common and most likely answer to this crossword clue is the 5 plus 5 letter word OUTER SPACE
I've seen this crossword clue in The Guardian
O
U
T
E
R
S
P
A
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E
More clues leading to the result OUTER SPACE
- Organised peace tours where atmosphere’s lacking
- Europe cast unfairly as ‘place lacking atmosphere’
- Place with no atmosphere is free, peer’s upset about account
- Performing troupes needing expert for place lacking atmosphere
- Infinitely large border in the garden, perhaps
- Europe cast unfairly as 'place lacking atmosphere'
- Prosecute a criminal in a place far away
- Ace troupe’s represented something studied by astronomers
- Divulged, on returning, room where aliens might be
Buddy explains!
The straight part
We know that "something studied by astronomers" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case something studied by astronomers = outer space.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.