Scientists and researchers say the protective magnetic layer surrounding each planet expanded unexpectedly in response to the sudden cessation of the solar wind. recent research Published in Journal of Geophysical Research: Space Physics.
Disturbances in Mars’ magnetosphere caused by changes in the solar wind could help paint a more detailed picture of how Mars lost water billions of years ago, study authors say .On Earth, scientists say they understand. Lulls in the solar wind are important because they can cause interference with satellites and communications.
Impact of solar wind on Mars
About 4 billion years ago, Mars is thought to have been covered with oceans, rivers, and lakes. Over time, liquid water disappeared from the surface. Scientists are interested in studying variations in the solar wind around Mars because it may reveal different scenarios that lead to water loss.
So far, scientists know how strong solar winds affect Mars’ atmosphere. Billions of years ago, a relentless stream of solar particles and ultraviolet light usurped its magnetic field. The weakening of the magnetic field may have caused more ions on Earth to escape into space, including water.
“For water to be in a stable liquid state, there has to be enough atmospheric pressure on it,” co-author Shannon Curry, a planetary physicist at the University of California, Berkeley, said at a press conference. Ta. As Mars’ atmosphere eroded, “atmospheric pressure rose, water began to evaporate, and was lost to space.”
NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) has been observing Mars for nearly a decade, reporting how solar particles are eroding the planet’s atmosphere and its now-defunct liquid water. . scientists learned Most of the ions were lost into space and during intense solar wind formations.
However, no observations have been made until now when there is almost no solar wind around Mars.
Around December 26th, the MAVEN spacecraft observed something unusual. As a new study explains, the density of the solar wind around Mars has decreased by a factor of 100. Mars’ altitude above the magnetosphere tripled in size by several thousand kilometers without being compressed by the pressure of the solar wind.
Lead author Jasper Harekas, an astrophysicist at the University of Iowa, said the situation was exacerbated by the collision of two different solar winds. The fast solar wind acted like a snow shovel, pushing out the weaker, slower solar wind and removing the space behind it.
The next day, Mars’ atmosphere returned to normal size. Harekas said other low-density solar wind events have occurred around Mars since then, but this was the longest and most dramatic.
But how do these same events affect our vibrant planet?
On its way to Mars in December 2022, a vacuum of solar wind collided with Earth.
Another NASA mission observed an expansion of Earth’s magnetosphere as the solar wind decreased around Earth, Harekas said.shock waves around the earth known as bow shockthat number is not included in the new study, but he said it has doubled.
But this was not the first or most dramatic disappearance of the solar wind around Earth. 1999another lull increased the bow shock around Earth by a factor of five.
In fact, a group of researchers found From 1995 to 2017, nearly a dozen low-density solar wind events occurred around Earth, but many more may have gone undetected. Radio astronomer Janardhan Padmanabhan, who helped study the past event, said he would also analyze the December 22 event.
Padmanabhan, a senior scientist at India’s National Academy of Sciences, said that during these events, “the entire Earth was engulfed in this giant low-density, slow-moving bubble.”
Scientists are primarily interested in cases where the solar wind toward Earth is stronger than normal. Solar particles can collide with our protective magnetic shield, causing effects ranging from auroras to radio interference to disruption of satellite operations.
But Ryan Dewey, an astrophysicist at the University of Michigan who was not involved in the study, said Earth could experience similar effects with lower-density solar wind.
Low-density solar wind events expand nearly all of Earth’s magnetosphere — including radiation belts made up of billions of high-energy particles that help protect Earth from harmful energy, he said. He said that it also includes. For example, when these radiation belts move over communications or GPS satellites, the influx of particles can become a hazard to spacecraft.
“They do affect the propagation of radio waves in Earth’s atmosphere and therefore interfere with communications,” said Alison Jaynes, a space and plasma physicist at the University of Iowa who was not involved in the study.
A decrease in the solar wind can also cause unusually heavy polar rain (a type of aurora). May 1999said Jaynes.allow sunlight The particles go straight to the Earth’s polar regions. It’s like a busy highway suddenly becoming clear.
But there are downsides to the clear highway for satellite carriers.Particle precipitation depends on its nature That volume could heat the upper atmosphere, Dewey said. That heat could cause the atmosphere to expand outwards, dragging the satellite with it.
Padmanabhan said low traffic could pave the way for greater danger to the Earth from the sun. If a major eruption of the sun, known as a coronal mass ejection, continues, it could have a major impact on Earth’s radio, railway, electrical systems, and satellite communications.
If such a coronal mass ejection were headed toward Earth during a solar wind extinction event, Padmanabhan says, “I can’t imagine what kind of catastrophe it would cause.”