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Science Fiction Network, December 7 (Zhu Xiwei) The solar system exists in a bubble, and wind and radiation from the sun flow outward, pushing into interstellar space, forming a boundary, known as the "heliosphere". Within this boundary, objects in the solar system are not affected by the powerful cosmic radiation.
Astrophysicists at the University of Maryland say the shape of the heliosphere can affect how cosmic rays enter.
In fact, the boundaries of the heliosphere are invisible, and it is not easy to figure out its shape, but it is not impossible. Based on data from the space probe, scientists determined in 2020 that the shape of the heliosphere may be a bit like a croissant.
Now that scientists know the rationale, the neutral hydrogen particles flowing into the solar system from interstellar space may have played a key role in shaping the shape of the heliosphere.
The Solar magnetic field and the interstellar magnetic field interact, and two streams of material emanate from the Sun's poles to form a heliospheric jet. However, instead of shooting directly, they bend under the impetus of interstellar currents, like the ends of a croissant. This is similar to other astrophysical jets observed in space, and like other jets, the sun's jets are unstable. In addition, the heliosphere, shaped by the Sun, also appears to be unstable.
To figure out why, the team performed computational modeling, focusing on the study of neutral hydrogen atoms. When the researchers removed neutral hydrogen atoms from the model, the solar jet suddenly became stable. When the neutral hydrogen atoms are put back, the model begins to bend, the central axis begins to swing, and something inside the heliospheric jet becomes very unstable.
According to the team's analysis, this is because the neutral hydrogen atom interacts with the ionized material in the outer region of the heliosphere. In other words, when a lighter fluid is pushed into a heavier fluid, instability is created at the interface between the two fluids. In turn, large turbulence is created at the tail of the heliosphere.