Parker probe observes powerful coronal mass ejection ‘vacuum up’ interplanetary dust

On Sept. 5, 2022, NASA’s Parker Photo voltaic Probe soared gracefully by way of one of the vital {powerful} coronal mass ejections (CMEs) ever recorded—not solely a formidable feat of engineering, however an enormous boon for the scientific neighborhood. Parker’s journey by way of the CME helps to show a 20-year-old idea concerning the interplay of CMEs with interplanetary dust, with implications for space climate predictions. The outcomes had been just lately revealed in The Astrophysical Journal.

A 2003 paper theorized that CMEs could work together with interplanetary dust in orbit round our star and even carry the dust outward. CMEs are immense eruptions from the sun’s outer ambiance, or corona, that assist drive space climate, which may endanger satellites, disrupt communications and navigation applied sciences, and even knock out energy grids on Earth. Studying extra about how these occasions work together with interplanetary dust might assist scientists higher predict how rapidly CMEs might journey from the sun to Earth, forecasting when the planet might see their affect.

Parker has now noticed this phenomenon for the primary time.

“These interactions between CMEs and dust had been theorized 20 years in the past, however had not been noticed till Parker Photo voltaic Probe considered a CME act like a vacuum cleaner, clearing the dust out of its path,” stated Guillermo Stenborg, an astrophysicist on the Johns Hopkins Utilized Physics Laboratory (APL) in Laurel, Maryland, and lead creator on the paper. APL constructed and operates the spacecraft.

This dust is made up of tiny particles from asteroids, comets, and even planets, and is current all through the solar system. A kind of faint glow referred to as zodiacal gentle, typically seen earlier than dawn or after sundown, is one manifestation of the cloud of interplanetary dust.

The CME displaced the dust all the best way out to about 6 million miles from the sun—about one-sixth of the space between the sun and Mercury—nevertheless it was replenished virtually instantly by the interplanetary dust floating by way of the solar system.

In-situ observations from Parker had been vital to this discovery, as a result of characterizing dust dynamics within the wake of CMEs is difficult from a distance. Based on the researchers, Parker’s observations might additionally present perception into associated phenomena decrease down within the corona, corresponding to coronal dimming brought on by low-density areas within the corona that always seem after CMEs erupt.

Scientists noticed the interplay between the CME and dust as decreased brightness in photographs from Parker’s Huge-field Imager for Photo voltaic Probe (WISPR) digital camera. It’s because interplanetary dust displays gentle, amplifying brightness the place the dust is current.

To find this incidence of decreased brightness, the staff needed to compute the common background brightness of WISPR photographs throughout a number of comparable orbits—sifting out regular brightness variations that happen as a consequence of solar streamers and different adjustments within the solar corona.

“Parker has orbited the sun 4 occasions on the identical distance, permitting us to check information from one go to the following very nicely,” Stenborg stated. “By eradicating brightness variations as a consequence of coronal shifts and different phenomena, we had been in a position to isolate the variations brought on by dust depletion.”

As a result of scientists have solely noticed this impact in reference to the Sept. 5 occasion, Stenborg and the staff theorize that dust depletion could solely happen with essentially the most {powerful} CMEs.

However, learning the physics behind this interplay could have implications for space climate prediction. Scientists are simply beginning to perceive that interplanetary dust impacts the form and velocity of a CME. However extra research are wanted to know these interactions higher.

Parker accomplished its sixth Venus flyby, utilizing the planet’s gravity to sling itself even nearer to the sun for its subsequent 5 shut approaches. This happens because the sun itself is approaching solar most, the interval within the sun’s 11-year cycle when sunspots and solar activity are most ample. Because the sun’s exercise will increase, scientists hope to have the chance to see extra of those uncommon phenomena and discover how they could have an effect on our Earth setting and the interplanetary medium.