A new study funded by the National Aeronautics and Space Administration (NASA) has revealed that the heliosphere of the sun is dominated by two giant jets of material that blasts over the star's south and north pole.
As the sun travels through the galaxy, it releases charged particles in a plasma stream known as the solar wind, which in turn produces the heliosphere, a magnetic bubble that extends far beyond the Solar System's planets.
Scientists have long thought that the heliosphere has shape comparable with that of a comet with a long tail that extends about 464 billion miles or thousands of times the distance between the Earth and the sun.
It was thought that the heliosphere's shape has something to do with its interaction with interstellar magnetic field but new observations and model suggest that the sun's own magnetic field actually dominates this shape.
Merav Opher, from Boston University, and colleagues, whose new study was published in the Astrophysical Journal Letters, were able to determine the new shape of the heliosphere when they adjusted its simulations based on data that were collected by NASA's Voyager 1 spacecraft. The NASA space probe was launched in 1977 to study the outer solar system.
The new research suggests that the heliosphere is dominated by two tails that are formed from the jets that protrude from the north and south poles of the sun and which are confined by the interaction between the sun's magnetic field and interstellar magnetic filed.
Thus, the heliosphere is now characterized without the long tail with its appearance appearing like a crescent moon rather than a comet.
The two jets are a lot like other astrophysical jets that are seen in space. For this reason, scientists hope that studying them could pave way to understanding these jets in the universe.
Jim Drake, from the University of Maryland said that heliosphere's shape is influenced by the solar wind jets that emanate from the sun saying that in the absence of interstellar flow, the magnetic field around sun would form the solar winds into jets that point straight south and north. He added that the magnetic fields contract around the jets and shoot the solar winds like a squished toothpaste tube.
"Our jets are nearby so we might be able to figure out how they produce the energetic particles measured in the heliosphere," Drake said.
Photo: M. Opher
