Hubble Detects Ghostly Glow Surrounding Our Solar System

Astronomers searched through 200,000 archival images from Hubble Space Telescope and made tens of thousands of measurements on these images to look for any residual background glow in the sky. Like turning out the lights in a room, they subtracted the light from stars, galaxies, planets and the zodiacal light. Surprisingly, a ghostly, feeble glow was left over. It's equivalent to the steady light of ten fireflies spread across the entire sky. Phys.Org reports: One possible explanation is that a shell of dust envelops our solar system all the way out to Pluto, and is reflecting sunlight. Seeing airborne dust caught in sunbeams is no surprise when cleaning the house. But this must have a more exotic origin. Because the glow is so smoothy distributed, the likely source is innumerable cometsâ'free-flying dusty snowballs of ice. They fall in toward the sun from all different directions, spewing out an exhaust of dust as the ices sublimate due to heat from the sun. If real, this would be a newly discovered architectural element of the solar system. It has remained invisible until very imaginative and curious astronomers, and the power of Hubble, came along. The research papers are published in The Astronomical Journal and The Astrophysical Journal Letters.

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