In this old image, which was released back in the late 90’s, Hubble spied with its right eye something… well. What is it? As it turns – pictured near the center (where the small arrow points) is a lone neutron star, wandering about the interstellar medium.
This is incredible for several reasons, but lets just start with the discovery of the object at all. Neutron stars – the remnants of massive stars that went supernova, without having the appropriate mass to collapse into a singularity – are very small – typically only a few kilometers in diameter.
This particular one is believed to be merely 16.8 miles (or about 28 kilometers) across, with its location coming in at an estimated 400 light-years from Earth (it can be found in the constellation of Coronae Australis). Despite being so small and distant, the compact object is still very hot and quite bright; making it stick out like a sore thumb from its immediate surroundings.
With that in mind, take a moment to appreciate the fact that Hubble can resolve such an extraordinarily unlikely find. That – paired with the fact that Hubble experienced several major problems during the first ten years of its mission – make a seemingly uninteresting object fascinating.