This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: A University of Iowa-led research team has reported in a new study the most detailed observations to date of the bow shock at Jupiter, our solar system's gas giant. The findings from NASA's Juno mission reveal key differences between Jupiter's bow shock and Earth's.
They also may lead to a better understanding of the physics of how shocks function in even more powerful energy releases, such as those from dying stars. The research is published in Nature Communications. The bow shock is an invisible boundary between the sun and a planet's magnetic field.
It is the first line of defense against the supersonic burst of energetic particles from the sun known as the solar wind. On Earth, the bow shock is important because it marks the point where the solar wind is slowed, heated and then deflected around Earth. If that didn't happen, our planet would be bombarded by the solar wind, and those harmful particles could reach our atmosphere and make Earth less safe for life.
Because Jupiter is a gaseous planet, scientists have been interested in understanding how its bow shock physics differs from Earth's and what it means for other planets and bodies in the universe. In the study, the researchers found that Jupiter employs multiple frequencies of plasma waves, which they call "harmonics," to counteract the solar wind's strength. It's like generating a richer musical note by playing multiple chords with one strum of a guitar: The more frequencies used by the plasma waves, the more effectively they can absorb the solar wind's impact at the bow shock.
On Earth, plasma waves at the bow shock use mostly a single frequency, enough to deal with the solar wind. "Jupiter has found its own way to deal with the solar wind, through plasma waves that are stronger and exhibit richer harmonic structures," said Jayasri Joseph, a postdoctoral researcher in the Department of Physics and Astronomy at Iowa and the study's corresponding author. "That's important because if you have multiple frequencies, you can heat more particles in the solar wind and slow them down." The researchers found another difference between the two planets: Jupiter employs a series of regions, called shocklets, to engage with the solar wind and slow it before it meets the planet's main bow shock.
Earth, by contrast, keeps it simpler, employing its bow shock as the sole main barrier. "Earth does not need to take these extra steps to handle the solar wind because the impact isn't as powerful," said Bill Kurth, a research scientist in the Department of Physics and Astronomy at Iowa and study co-author who has been involved with the Juno mission since its launch in 2011. The researchers say the bow shock physics at Jupiter could help explain how stars or other distant bodies handle the enormous volume of energy released by supernova remnants, the cataclysmic final stages of dying stars.
Extract — continue reading at the source.
