Dust ring discovered in Mercury’s orbit

Two dusty discoveries may shake up our understanding of the inner solar system, says Fox News.

Mercury shares its supertight orbit with a big ring of wandering dust, a recent study suggests. And a cloud of as-yet-undiscovered asteroids likely gave rise to a similar halo in Venus’ neighborhood, another new paper concludes.

“It’s not every day you get to discover something new in the inner solar system,” Marc Kuchner, a co-author of the Venus study and an astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, said in a statement. “This is right in our neighborhood.”

A ring very close to the sun

Both Earth and Venus have collected co-orbiting dust rings, as the planets have shepherded the particles with powerful gravitational tugs. Mercury’s path, however, was thought to be free of such a feature.

“People thought that Mercury, unlike Earth or Venus, is too small and too close to the sun to capture a dust ring,” Guillermo Stenborg, a solar scientist at the Naval Research Laboratory in Washington, D.C., said in the same statement. “They expected that the solar wind and magnetic forces from the sun would blow any excess dust at Mercury’s orbit away.”

But Stenborg and his colleagues shattered that expectation. The researchers analyzed images captured by one of NASA’s twin Solar and Terrestrial Relations Observatory (STEREO) spacecraft, both of which launched into orbit around the sun in 2006.

The researchers created a model based on these photos in an attempt to “edit out” dust that could make it more difficult to understand the data gathered by STEREO, NASA’s recently launched Parker Solar Probe and other sun-studying craft.

When they applied the model to the STEREO imagery, the astronomers saw dust — a lot more of it than they anticipated.

“It wasn’t an isolated thing,” co-author Russell Howard, also a solar scientist at the Naval Research Laboratory, said in the same statement. “All around the sun, regardless of the spacecraft’s position, we could see the same 5 percent increase in dust brightness, or density. That said something was there, and it’s something that extends all around the sun.”

The team calculated that the dust ring is about 9.3 million miles (15 million kilometers) wide. The researchers reported their results last November in The Astrophysical Journal.

Continued here.