For most of human history, the night sky was our map, our calendar, our clock and our greatest source of wonder.

Then we invented streetlights, glowing billboards, parking lots—and cities that never truly become dark. Somewhere along the way, many of us stopped looking up.

Astro-tourism is changing that.

In the past six months, one dear friend and one close associate have been diagnosed with Parkinson’s disease. Both had important trips planned—and both had to cancel because of the physical effects of the disease.

In the past ten months, two women I know have been diagnosed with breast cancer.

These were people making plans and assuming, as most of us do, that there would be plenty of tomorrows. . .