Readers ask about Saturn’s icy rings, transparent fish and more

Icy hot

Ice particles from Saturn’s rings are falling into the planet’s atmosphere. In part because the particles vaporize, energy is released, heating up and making the sky glow at ultraviolet wavelengths, Ken Croswell reported in “Saturn’s icy rings may bring the heat” (SN: 5/6/23 & 5/20/23, p. 18).

Some readers asked how energy could be released given that energy is typically consumed during vaporization.

Vaporizing water does require energy, Croswell says, but other processes are at play. Collisions between falling ice particles and atmospheric gas deposit heat energy into the air from friction. Ultraviolet radiation from the sun also breaks up water molecules, creating free-range “hot” hydrogen atoms that raise the atmosphere’s temperature.