Personally, my favourite item of clothing inspired by space was a stars-and-moons nightgown that I had when I was little. Unfortunately, readers, I cannot find the aforementioned nightgown in either real life, or online. Sorry.
However, there is a wider range of options for mature women in terms of starry fashion. A good example would be a manicure inspired by galaxies, which I first saw on Tumblr. The lovely ladies at LOVELYish posted a tutorial here on how to do galactic nails, which I couldn't have said better.
A picture from LOVELYish's galactic nail tutorial.
Source: LOVELYish
One can make tie-dye clothing with certain dyes in order to create space-inspired clothing. A few choice colours would be black, dark blue, purple, with gold and silver fabric spray paints. I myself haven't done this yet, but when I do I will most definitely post pictures.
Other than clothing and nails, certain accessories can be added. Millions of websites have jewellry with stars, moons, and suns as pendants. Abalone, or other pearlescent gemstones looks beautiful inlaid in silver and fit in well with a galactic theme. Below are a few examples of my favourite pieces of jewellry.
Source: Tumblr (w1ldbunny)
Source: Amazon
I like the rustic feel of this one.
Source: Tumblr (sittingbutterfly)
My only concern is if you wear any of these, people won't just reach for the stars, they'll reach for your jewellry.
(OK, that was weak.)