Signs of the Zodiacal

StarryEarth, CC BY-NC 2.0 A column of zodiacal light stretches skyward beyond Mount Teide in the Canary Islands. If you’ve ever been under a dark sky in the early morning before dawn, you may have seen a faint glow, almost like a column of light rising from the east. It’s sometimes known as the false dawn, since it appears before true dawn. It can also appear in the west after sunset, though it typically isn’t as noticeable. The glow is caused by dust in the inner solar system. A diffuse plane of tiny particles that aligns with the plane of the inner planets. Since the planets move through the zodiac constellations, so does this plane of dust. Which is why it is also known as the zodiacal light. Most exoplanetary systems likely have a similar plane of zodiacal dust, particularly systems with rocky, potentially habitable worlds. If we see zodiacal dust around a star, that could indicate that rocky inner planets orbit the star. But since this dust reflects starlight, it could also…