Return to Pluto

Mountains made of water ice. Glaciers of frozen nitrogen. A thin, layered atmosphere-and the possibility of an ocean beneath it all.

Pluto is a small world with enormous scientific surprises. When NASA's New Horizons spacecraft swept past in July 2015, it revealed a landscape far more varied and active than many had expected. Yet the encounter was brief. Much of Pluto remains poorly mapped, and some of its most intriguing discoveries still await an explanation.

What would we discover if we returned-and stayed?

In Return to Pluto, aerospace and nuclear engineer Dr. Ugur Guven takes curious readers from the evidence gathered by New Horizons to the scientific and engineering challenges of a dedicated return mission.

Explore Sputnik Planitia's vast nitrogen glacier, methane-rich ridges, possible ice volcanoes, and the contrasting landscapes of Charon. Discover how scientists measure a distant world's size, identify its surface materials, investigate its atmosphere, and build competing models of an interior they cannot see.

Then follow a specific proposal for returning: Persephone, a published mission concept involving a journey through the outer Solar System and a multi-year investigation of the Pluto-Charon system. Examine its proposed instruments, orbital tour, propulsion, nuclear power supply, and communications-and understand how each serves a particular scientific question.

Across 18 chapters, 44 figures and images, and 14 data tables, the book explains:

• What Pluto's measured properties reveal about its composition and history.
• How nitrogen glaciers, methane frost, and atmospheric haze shape this unfamiliar world.
• Why a subsurface ocean remains possible-and what evidence could help test it.
• What New Horizons discovered, how its instruments worked, and what its flyby could not resolve.
• How an orbiter could investigate Pluto, Charon, and the smaller moons repeatedly.
• Why reaching Pluto and slowing down enough to remain are very different challenges.

Written for interested adults, students, and space enthusiasts, Return to Pluto combines accessible explanations with scientific data, worked examples, a glossary, and references. No specialist mathematics is required to follow the main narrative.

The first encounter revealed a world. A return mission could help us understand it.