Earth is the sixth planet from the solar system’s edge. A 3D map of the solar system’s edge is one of the latest development that took 13 years to create. It revealed a few more details about the outer heliosphere.
According to Dan Reisenfeld, a space science researcher at Los Alamos National Laboratory in New Mexico and head of the team that researched the 3D map, the outer heliosphere is the region of space where the stream of charged particles emitted from the sun or the solar wind by the interstellar radiation is “deflected and draped back” that spread throughout the empty space beyond the solar system. Interstellar particles and solar wind meet and form a boundary at the far reaches of the solar system.
According to NASA earthlings, in 2012 1st got a glimpse of the solar system’s outer edge when Voyager I, a NASA spacecraft, crossed into interstellar space. The spacecraft was launched in 1977. In 2018, Voyager 2 was not far behind, repeating the feat. Both Voyagers 1 and 2 reported a substantial increase in galactic radiation and a sudden dropoff in solar particles when they left the solar system, according to NASA’s Jet Propulsion Laboratory at California Institute of Technology.
The inner layer where the sun and its planets lie is roughly spherical and in all directions is thought to extend roughly 90 astronomical units. The outer layer is much less symmetrical. Lack of symmetry is because of the sun’s movement through the Milky Way, with the galactic radiation in front of it experiences friction and clears out space in its wake.
According to Reisenfeld, “There’s a lot of plasma [charged particles] in the interstellar medium, and… the inner heliosphere, which is pretty round, is an obstacle in this stream of plasma which is flowing past it. It has the same effect as water going around a rock in a stream, with a rush of water crashing into the rock in front and a sheltered calm behind it.”
According to NASA, using the Interstellar Boundary Explorer (IBEX), measurements for the 3D map were gathered, is “the size of a bus tire” and which was launched in 2008. Solar wind particles are detected by IBEX that have bounced back from the edges of the solar system, which helped to find the distances involved by measuring how long their round trip took for Reisenfeld and his colleagues. “The sun will send out a pulse … and then we passively wait for a return signal from the outer heliosphere, and we use that time delay to determine where the outer heliosphere must be,” Reisenfeld explained.
Reisenfeld said there is a correlation between the number of spots on the sun and solar wind strength. Due to intense magnetic disturbances within a sunspot temporarily appears on the surface of the sun, which is the relatively dark patch. NASA plans to launch a new mission to learn more about the heliosphere, called the Interstellar Mapping and Acceleration, in 2025.