Tens of thousands of measurements on 200,000 archival images were analyzed.
The Hubble telescope has detected, after the analysis of tens of thousands of measurements in 200,000 archival images, a faint ghostly glow that surrounds the Solar System. Related news How is the gigantic “magnetic tunnel” that according to a group of scientists surrounds the solar system Spaceship Lucy begins a 12-year adventure to discover the origin of the Solar System about 1 year ago The astronomers decided to investigate how black the night sky really is. To do this, they searched for any residual background glow in the sky, in an ambitious project called SKYSURF. This would be any light left over after subtracting the brightness of planets, stars, galaxies, and dust in the plane of our Solar System (called zodiacal light).
When the researchers completed this inventory, they found an extremely small excess of light, equivalent to the constant brightness of 10 fireflies spread across the entire sky. That’s like turning off all the lights in a closed room and still finding a ghostly glow coming from the walls, ceiling and floor, details Europa Press. The researchers say that one possible explanation for this residual glow is that our inner solar system contains a faint sphere of dust from comets falling into the solar system from all directions, and that the glow is sunlight reflecting off this dust. If real, this layer of dust could be a new addition to the known architecture of the solar system. This idea is reinforced by the fact that in 2021 another team of astronomers used data from NASA’s New Horizons spacecraft to also measure the sky background.
New Horizons flew past Pluto in 2015 and a small Kuiper belt object in 2018, and is now heading into interstellar space. The New Horizons measurements were made at a distance of 6 to 7.5 billion kilometers from the sun. This is outside the realm of planets and asteroids where there is no contamination by interplanetary dust. New Horizons detected something slightly fainter, apparently coming from a more distant source than Hubble detected. The source of the backlight seen by New Horizons also remains unexplained. There are numerous theories ranging from the decay of dark matter to a huge invisible population of remote galaxies.
“If our analysis is correct, there is another dust component between us and the distance where New Horizons made the measurements. That means it’s some kind of extra light coming from inside our Solar System,” Tim Carleton of Arizona State University (ASU) said in a statement. “Because our measurement of residual light is higher than that of New Horizons, we think it is a local phenomenon not too far from the solar system. It may be a new element of solar system content that has been hypothesized but not quantitatively measured until now,” added Carleton.