Before sunrise on a truly dark night, a faint glowing pyramid of light can rise from the horizon and fool observers into thinking dawn has arrived. That glow is the zodiacal light, sunlight scattering off a vast pancake-shaped cloud of interplanetary dust spread along the plane of the solar system. This episode explains why forward scattering makes the glow brightest near the hidden sun, why particles only 10 to 300 micrometers across and kilometers apart can still add up to a visible pillar, and how the gegenschein and zodiacal band stretch across the whole sky under pristine conditions.

We trace the debate over where the dust comes from, from the Poynting-Robertson effect that spirals grains into the sun to the Rosetta mission’s COSIMA instrument attributing over 85 percent of the dust to crumbling Jupiter-family comets, and the Juno spacecraft’s accidental discovery of dust impacts that point toward a puzzling Martian origin. Along the way we cover fluffy micrometeorites collected in Antarctic snow, the role of the false dawn in Islamic prayer and fasting times, Cassini and Fatio de Duillier’s early theories, and how Queen guitarist Brian May finished his 1974 astrophysics thesis on zodiacal dust in 2007.

• When and where to look for the zodiacal light, and why moonlight or light pollution washes it out
• How sunlight acts as a headwind that drags dust inward while radiation pressure blows the smallest grains away
• What Rosetta’s COSIMA instrument revealed about dormant, crumbly Jupiter-family comets
• Why Juno’s solar panels became the largest dust detector ever flown and what the 2.06 AU boundary suggests
• How Muhammad’s descriptions of the false dawn and true dawn still guide the timing of Fajr and Ramadan fasting