As per Oxford learner’s dictionary when referring external earth’s atmosphere, definition #15, space is an unaccountable noun…. Can space be accompanied by indefinite or definite articles.

In the context of ridiculous, the meaning of bold should be read as outrageous, which is

a synonym of stupid.

I think it is more for the usage, there are slightly different nuances. Usage of when the object is specified.

Your father should be informed of your conduct.

Use about when the object is not specified:

Your father should make sure about all nonsense you said.

What causes a black hole?