A study based on NASA research and published in The Astrophysical Journal reveals a cosmic dust ring in Mercury’s orbit. The ring is approximately 15 million kilometers wide (9.3 million miles) and — although unknown until now — has likely been present for billions of years.
Unlike Venus and Earth, scientists previously believed that Mercury was too close to the sun to be able to capture a dust ring. In particular, they believed that the sun’s magnetic forces and solar winds would throw any dust in Mercury’s orbit in the opposite direction.
From the view of the Earth, it appears that there is dust everywhere due to the clouds of dust blocking our vision. To find spaces that are dust-free, scientists look for regions of space where the force of the sunlight is not reflected to the Earth from the dust particles in space.
But when sunlight does reflect off of dust particles, it creates a force approximately 100 times brighter than the force of the original light. Although scientists often discard this data, the team behind the recent study kept it by chance, according to Science Alert. And using images from NASA’s STEREO satellite, they generated a model to separate both types of light.
Russell Howard, a solar scientist at the Naval Research Laboratory in Washington, D.C., said that the team noticed a pattern of brightness that indicated high levels of dust.
“It wasn’t an isolated thing. All around the sun, regardless of the spacecraft’s position, we could see the same five percent increase in dust brightness, or density. That said something was there, and it’s something that extends all around the sun.”
Although the new discovery is unexpected, the team still hopes to examine dust-free zones. And with the Parker Solar Probe exploring the plasma that surrounds the sun, scientists can use the team’s model to reveal other dust clusters close to the sun.
As per NASA, dust rings around planet’s like Mercury and Venus are just two of many. In distant star systems, there are many others, and they are essential because they can be used to infer the orbital properties of hidden planets that have yet to be discovered. However, making these kinds of inferences can be difficult.
“In order to model and accurately read the dust rings around other stars, we first have to understand the physics of the dust in our own backyard,” said Marc Kuchner, an astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
Luckily, continued research of dust rings around planets like Mercury, Venus, and Earth will help advance this research.