A few months ago, I flew to Houston to visit a small startup called Lunar Resources, which aspires to build the largest telescope in the solar system—not on Earth but on the far side of the moon.

The telescope is barely a concept yet — it may be thwarted by funding or engineering problems before it ever reaches a launchpad or derailed by an instrument malfunction once it reaches space.

Jacob Payne, a graduate student and research assistant at the University of Iowa’s Department of Physics and Astronomy, landed a NASA grant to build a small X-ray telescope that can assist with deep ...