‘Ghostly glow’ in the solar system could be ‘new addition’ to our understanding of its structure

A mysterious ‘ghostly glow’ equivalent to 10 fireflies has been found around our solar system that persists even when other light sources such as stars and planets are subtracted.

The discovery was made as astronomers set out to see just how dark space can be, which they did by examining 200,000 images taken by NASA’s Hubble Space Telescope and removing the expected glow, but a small excess of light prevailed.

The scientists can’t be sure where the light is coming from, but they hypothesize that the source is a previously unknown sphere made up of comet dust, which reflects sunlight.

If confirmed, the researchers said this layer of dust would be a new addition to the known architecture of the solar system.

This discovery builds on research conducted in 2021 when another group of astronomers used data from NASA’s New Horizon interplanetary space probe to measure the sky background.

New Horizon also detected a glow around the solar system, but the probe was more than four billion miles from the sun, and the cause remains a mystery to this day.

Numerous theories range from the decay of dark matter to a huge invisible population of remote galaxies.

Tim Carleton of Arizona State University (ASU) said in a statement: ‘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.”

Carleton went on to explain that since the light appeared dim in the New Horizons data due to its distance, the glow must be coming from the fringes of the solar system.

“It may be a new element of the content of the solar system that has been hypothesized but not quantitatively measured until now,” he said.

This led to recent work using Hubble, which is about 340 miles above the Earth’s surface.

Veteran Hubble astronomer Rogier Windhorst, also of ASU, said in a statement: “More than 95 percent of the photons in the archive Hubble images come from distances less than 3 billion miles from Earth.”

“Since the early days of Hubble, most Hubble users have dismissed these photons from the sky as they are interested in the faint discrete objects in the Hubble images, such as stars and galaxies.

“But these photons from the sky contain important information that can be gleaned thanks to Hubble’s unique ability to measure faint brightness levels with high precision over its three decades of life.”

Hubble, a joint project of NASA, the European Space Agency and the Canadian Space Agency, has been observing the universe for more than three decades.

It has made more than 1.5 million observations of the universe, and more than 18,000 scientific papers have been published based on its data.

The telescope orbits Earth at a speed of about 17,000 mph in low Earth orbit at about 340 miles in altitude, slightly higher than the International Space Station.

Launched in April 1990 from the Kennedy Space Center in Florida, Hubble is showing increasing signs of aging, despite a series of repairs and upgrades by spacewalking astronauts during NASA’s shuttle era.

The telescope is named after the famous astronomer Edwin Hubble, who was born in Missouri in 1889 and discovered that the universe is expanding, as well as the rate at which it is expanding.