To the human eye, Mercury may resemble a dull, grey orb but this enhanced-color image from NASAs Messenger probe, tells a totally different story. Swathes of iridescent blue, sandy-colored plains, and fragile strands of greyish white, develop an ethereal and colorful view of our Solar Systems inner world. Credit: NASA/ JHU Applied Physics Lab/ Carnegie Inst. Washington
Mercury is special. As the closest world to the Sun, it occupies an area where the Suns impact is changing dramatically. The Suns magnetic field, which dominates space close to the Sun, is rapidly waning. And Mercurys orbit– more elliptical or “oval-shaped” than any other world– enables it to experience a broader range of solar magnetic field conditions than any other world. As an outcome, Mercury provides a distinct opportunity to study how the Suns influence on a planet differs with distance.
In a brand-new study published in Nature Communications, Goddard scientists Norberto Romanelli and Gina DiBraccio utilized information from NASAs MESSENGER spacecraft to study the Suns changing interaction with Mercury. As Mercury moves through the solar wind, the constant stream of particles getting away the Sun, some of them strike Mercurys magnetosphere and recuperate towards the Sun. These rebounding solar wind particles generate low-frequency waves that reverberate through area, traveling “upstream” in the solar wind towards the Sun.
Romanelli and DiBraccio observed these waves originating from Mercury and discovered that the rate of wave production differed throughout Mercurys orbit. As Mercury moved further from the Sun it generated more waves; as it got closer, the rate of wave production dropped. The outcomes offer essential proof for a theory that these waves are impacted, in part, by the strength of the Suns electromagnetic field, which grows weaker with range.
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Mercury is unique not just because its the closest world to the Sun however also because the range it is from the Sun varies more than any other planet in our solar system.
Mercury in fact has a very oval-shaped orbit compared to the rest.
Mercury is a natural laboratory for running experiments. We can observe the worlds environments as it gets closer and farther away from the Sun and see what changes.
When solar wind particles bounce off this magnetospheric boundary, they produce low-frequency waves. Theyre like ripples taking a trip upstream in the solar wind.
Farther from the Sun, the Suns electromagnetic field is weaker. We found that this is the crucial specification that enables more waves to be generated.
This is something we might just have measured with Mercury, thanks to how close it is to the Sun and the shape of its orbit.
Recommendation: “Occurrence rate of ultra-low frequency waves in the foreshock of Mercury increases with heliocentric range” by N. Romanelli and G. A. DiBraccio, 19 November 2021, Nature Communications.DOI: 10.1038/ s41467-021-26344-2.
As an outcome, Mercury supplies an unique chance to study how the Suns impact on a planet varies with distance.
As Mercury moves through the solar wind, the constant stream of particles escaping the Sun, some of them strike Mercurys magnetosphere and bounce back towards the Sun. Romanelli and DiBraccio observed these waves originating from Mercury and discovered that the rate of wave production differed throughout Mercurys orbit. As Mercury moved farther from the Sun it produced more waves; as it got closer, the rate of wave production dropped.
