A huge hole in the Earth's magnetic field allowed a solar storm to penetrate

The huge breach that actually exposed the entire Earth to the solar wind for one day is 10 times larger than previously thought possible and may repeat itself in the current solar cycle

A group of five NASA spaceships called the Machines THEMIS They recently discovered a gap in the Earth's magnetic field, 10 times larger than what was previously considered the maximum gap. The solar wind can penetrate through the opening to charge the magnetosphere and create geomagnetic storms. The very existence of such loopholes is not the biggest surprise. The researchers are even more fascinated by the strange and unexpected way in which they are created, and the new knowledge gained turns many old ideas about space physics upside down. Remember, this is the second important discovery of the Themis satellites. The previous one was Discoveries of magnetic cables connecting the earth to the sun.

"At first I didn't believe it" said the chief scientist in the Themis project, David Sibek from the Goddard Space Flight Center. "The findings fundamentally change our understanding of the mutual influence between the solar wind and the Earth's magnetosphere.

The magnetosphere is a bubble of magnetism that surrounds the Earth and protects us from the solar wind. Exploring this bubble is one of the main goals of the Themis mission, which was launched in February 2007. The big discovery came on June 3, 2007 when the five spacecraft happened to pass through the hole just as it opened. The sensors they carry recorded a flood of solar wind particles flowing into the magnetosphere, indicating an event of an unexpected magnitude.

"This is a huge opening, 4 times the diameter of the Earth itself," said Wenhui Li, a space physicist at the University of New Hampshire who analyzed the data. Lee's colleague, Jimmy Reeder, also from New Hampshire, said "10 to the power of 27 particles per second entered the magnetosphere, meaning 1 followed by 27 zeros. This number is at least one order of magnitude more than we thought possible."

The event began almost without warning when a gentle gust of the solar wind brought a packet of magnetic fields from the Sun to Earth. Like an octopus wrapping its hunting arms around a clam, the magnetic fields drop themselves around the magnetosphere and crack it open. The crack is perfected through a process known as magnetic reconnection. Above the poles, at high altitude, the terrestrial and solar magnetic fields connected and formed a kind of channel for the solar wind. These trenches over the Arctic Ocean and over Antarctica spread rapidly and merged over the equator, creating the largest magnetic rift yet recorded by satellite.

The size of the breach surprised the researchers. "We've seen things like this before," Reeder said, "but never on this scale. Every day side of the earth was open to the solar wind." The results were even more surprising. Space physicists have until now believed that the holes in the magnetosphere only open when the Sun's magnetic fields face south. The June 2007 burst opened in response to north-facing solar magnetic fields. "To the common man this sounds like quibbling, but for space physicists it's like an earthquake," Sibek said. "When I tell this to my colleagues, most of them react with skepticism as if I'm trying to convince them that the sun rises in the west."

The explanation is simple. The solar wind presses on the Earth's magnetosphere almost directly above the equator, where the Earth's magnetic field faces north. If packets of magnetism arrive and point north as well, the two fields will reinforce each other, further tightening the magnetic field that protects the Earth and thus further closing the door to the solar wind. In the language of space physicists, a solar magnetic field facing north is called a northern IMF, and is equivalent to "the shields raised". Therefore, the surprise can be described when a northern IMF arrives and the defenders go down instead of going up," Sibek said. "This completely changes the understanding of things."

According to Reeder, northern IMFs do not drive geomagnetic storms, but they prepare the infrastructure for storms by charging the magnetosphere with plasma. A charged magnetosphere provides us with the phenomenon of the aurora borealis, and causes power outages and other disturbances that can be caused when a solar storm also arrives at the same time.

Rider awaits more surprises when We are entering the 24th solar cycle. For some unknown reason, even-numbered solar cycles tend to warm the Earth when the leading edge of the solar wind is magnetized to the north. This magnetic field can cause the atmosphere to charge, and make a way inward into the main part of the storm. "This is the leading scenario for a really big event," Reeder said.

Sibek agrees: "The result of the process will be stronger geomagnetic storms than we have seen for many years."

For information on the NASA website

A phenomenon related to the one described in this article: The oxygen leaks from the atmosphere into space through the aurora borealis