Scientists map the outside edge of the Sun’s atmosphere
Using multiple solar observatories in space, scientists have now been able to map the approximate location of the outside edge of the Sun’s atmosphere, the point “where the speed of the outward solar wind becomes faster than the speed of magnetic waves.”
The panels to the right are a sampling of that mapping, and is figure 3 of the peer-reviewed paper [pdf]. The bulk of the data (black) comes from five spacecraft observing the Sun from the L1 point a million miles from Earth. The blue line is data from Solar Orbiter, while the red line is data from the Parker Solar Probe. From the press release:
Astronomers have produced the first continuous, two-dimensional maps of the outer edge of the Sun’s atmosphere, a shifting, frothy boundary that marks where solar winds escape the Sun’s magnetic grasp. By combining the maps and close-up measurements, scientists from the Center for Astrophysics | Harvard & Smithsonian (CfA) showed that the boundary grows larger, rougher and spikier as the Sun becomes more active.
…The boundary in the Sun’s atmosphere where the solar wind’s outward speed becomes faster than the speed of magnetic waves, known as the Alfvén surface, is the “point of no return” for material that escapes the Sun and enters interplanetary space; once material travels beyond this point, it cannot travel back to the Sun. This surface is the effective “edge” of the Sun’s atmosphere, and provides scientists with an active laboratory for studying and understanding how solar activity impacts the rest of the solar system, including life and technology on and around Earth.
This new data further refines the nature of the boundary, as earlier probes had already given scientists a rough idea of its size and nature.
Using multiple solar observatories in space, scientists have now been able to map the approximate location of the outside edge of the Sun’s atmosphere, the point “where the speed of the outward solar wind becomes faster than the speed of magnetic waves.”
The panels to the right are a sampling of that mapping, and is figure 3 of the peer-reviewed paper [pdf]. The bulk of the data (black) comes from five spacecraft observing the Sun from the L1 point a million miles from Earth. The blue line is data from Solar Orbiter, while the red line is data from the Parker Solar Probe. From the press release:
Astronomers have produced the first continuous, two-dimensional maps of the outer edge of the Sun’s atmosphere, a shifting, frothy boundary that marks where solar winds escape the Sun’s magnetic grasp. By combining the maps and close-up measurements, scientists from the Center for Astrophysics | Harvard & Smithsonian (CfA) showed that the boundary grows larger, rougher and spikier as the Sun becomes more active.
…The boundary in the Sun’s atmosphere where the solar wind’s outward speed becomes faster than the speed of magnetic waves, known as the Alfvén surface, is the “point of no return” for material that escapes the Sun and enters interplanetary space; once material travels beyond this point, it cannot travel back to the Sun. This surface is the effective “edge” of the Sun’s atmosphere, and provides scientists with an active laboratory for studying and understanding how solar activity impacts the rest of the solar system, including life and technology on and around Earth.
This new data further refines the nature of the boundary, as earlier probes had already given scientists a rough idea of its size and nature.
