Astronomers have discovered a strange residual glow in the sky. To do this, they needed to analyze 200,000 archive images acquired by the Hubble Space Telescope and take tens of thousands of measurements as part of the ambitious SKYSURF project. Eventually, scientists ruled out light from stars, galaxies, planets, and other objects, but a faint, barely noticeable glow remained.
What causes this ghostly glow in our solar system? One of the hypotheses is that sunlight is reflected from the dust layer. Due to its uniform distribution, large numbers of small comets are the most likely source. As it approaches the Sun from all sides, the heat from it causes the ice to sublimate (bypassing liquid, turning from solid to gas), releasing a cloud of dust.
Scientists believe that if the hypothesis is confirmed, it is an entirely new piece of solar system architecture. The ghostly glow remained invisible until it was possible to look there with the aid of the Hubble telescope. Just last year, another group of astronomers measured the sky’s background using information from NASA’s New Horizons probe. It recently entered interstellar space after passing Pluto in 2015 and a small Kuiper Belt object in 2018. During the observations, New Horizons was between 4 and 5 billion kilometers from the Sun. The apparatus has detected a very faint glow and must be from a more distant source.
Now scientists agree that this could be a new element of the solar system.
Source: Port Altele
