The Cosmic Inside tee design is not just for the astronomy lovers, it is for everyone. As Carl Sagan said "We are all made of star stuff."
The concept is based on just that. Only it is taken to an extreme interpretation of having a complete galaxy within the human body. As above so below.
As for the artwork, the positive aspects are that the colors are bold and bright as a galaxy should be. The shading and highlights are great. The Superman shirt pull is a good vehicle for this idea. As for the negatives, the astronaut is drawn without legs which makes it seem incomplete to me. There is no background which isn't a deal breaker but some stars, a space shuttle, an asteroid or something could had been cool. You know to sell the point of it being an astronaut and not just someone in a spaceman costume that could be hanging out in their backyard or bathroom. But maybe that is the point. That this could be anyone, from any planet or from within.
The printed colors won't actually match the thumbnail on the retailer's website which is a downer so a point is taken away for that reason.
This Cosmic Inside tee will make an ideal gift for those people that dig astronomy, biology and philosophy.