Velocities in opposite directions in astronomical region (4,5)

I believe the answer is:

deep space

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'region' is the definition.
(deep space is a kind of region)

I don't understand the rest of the clue.

(Other definitions for deep space that I've seen before include "void" , "even devoid of 12 [THIN AIR]" , "Region beyond our atmosphere" .)

I've seen this clue in The Telegraph.

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