What happens at the edge of the Solar System?

Something strange and unforeseen is happening at the outer edge of the Solar System: the heliopause, the border between heliosphere (the bubble of solar wind that surrounds our planetary system) and the interstellar medium (the vast space between stars) is billowing at oblique angles that no one thought possible.

The idea that the heliopause can change its shape is not new, and in recent years several studies have been carried out with data from the probes Voyager 1 and 2 (the only human devices that for now managed to leave the Solar System) and the IBEX satellite (interstellar boundary explorer), they already discovered that this ‘border’ is not something static and immutable.

“The Voyager Spacecraft -Explain eric zirnsteina space physicist at Princeton University and lead author of a study just published in ‘Nature Astronomy’– they provide the only direct in situ measurement of the locations of these boundaries. But only at a point in space and time«. And the IBEX mission helps complete those measures.

With that data, researchers have been creating models that predict how the heliopause changes. And that’s how they realized that, simply put, the solar winds and the interstellar medium push and pull on each other to create a boundary that is constantly moving.

But recent work on the heliopause has yielded conflicting data that casts doubt on earlier findings. Over a period of several months in 2014, for example, IBEX captured the glow of energetic neutral atoms (ENAs), which are created when solar winds and the interstellar medium interact, and discovered a number of asymmetries in the heliopause. Only later did scientists realize that these asymmetries were inconsistent with existing models.

Abrupt change in the Solar System

Reviewing data from Voyager 1 and Voyager 2, Zirnstein and his team have found that the heliopause changed dramatically in a very short period of time. Which, in part, helps explain why so much time elapsed between the two probes’ entries into interstellar space, which took place six years apart in 2012 and 2018, respectively, despite both launching with just a few days apart, on August 20 and September 5, 1977.

And now, in his new article, Zirnstein qualifies those discrepancies as ‘intriguing and potentially controversial’. His plans, of course, are to continue studying the heliopause, hoping to learn more from NASA’s Interstellar Mapping and Acceleration Probe, a new and improved satellite that can detect ENA and is scheduled to launch in 2025. Until then , we can only reflect on this disturbing phenomenon that occurs in the furthest extremes of the Solar System, and ask ourselves what it could be due to.

Font: JOSE MANUEL NIEVES / ABC

Reference article: https://www.abc.es/ciencia/extrano-sucede-frontera-sistema-solar-20221028173253-nt.html