University of Maine physics and astronomy professor Neil Comins has found a niche for himself not only as a high-level star researcher, but also as an authoritative respondent to the age-old question: What if?

His first book, “What If the Moon Didn’t Exist?” (published in 1993), offered an accessible look at how the Earth might have turned out if the moon had never orbited around it, and “Heavenly Errors” (2001) set out to correct popular misconceptions in astronomy, and more (what if modern science had never been invented?). His new book, “The Hazards of Space Travel” out this month, answers the same question, with a twist: What if, while you’re tooling around in space, something goes wrong?

The possibilities are scary, naturally, and “The Hazards of Space Travel” seems to cover them all. For example, you won’t be able to walk around without a spacesuit even on Mars, which is the most Earth-like planet, because its atmosphere would choke you and is so thin and light your body could not adapt to it. On Jupiter’s moon Io, you’d be treading a “minefield” of volcanoes.

The Apollo astronauts, Comins tells us, ran a small risk of getting buried in lunar landslides.

The bio-problems of getting past the moon are so various and complex you start to wonder if it will ever be done at all. The spacecraft traps everything inside it, including waste gases such as carbon dioxide and carbon monoxide, which can eventually kill you if they’re not properly filtered out of the air. Mold and fungi proliferate if the humidity is not carefully controlled. Comins describes an Apollo-Soyuz mission of 1975 when gas leaks developed that spurred dangerous inflammations of the astronauts’ lungs. Then there are the meteoroids – tiny rocky particles – that can punch holes in the ship, and high-energy radiation that can ravage your DNA. The list goes on and on, all the way to the hazards of boredom in long, cramped journeys.

The book tries to spice up the dutiful rehearsal of copious space facts by offering at the start of each chapter an excerpt from the “log” of fictional spaceman Mack Richardson. Mack’s name could easily have turned up in a 1950s “I, Robot” story, and reflects the tone and approach of his interplanetary narrow scrapes.

Ferreting out and describing every possible thing that can go wrong seems like a peculiar way to encourage space exploration and tourism. But Comins’ detailed knowledge and enthusiasm for the topic nonetheless come through, and this book may be enjoyed by many an armchair space traveler who will never have to worry about whether his oxygen tank is going to fail.