NASA is monitoring a ‘small but evolving dent’ in Earth’s magnetic field that could impact satellites and spacecraft.
Stretching from South American and to southwest Africa is the South Atlantic Anomaly (SSA), which is a weakened spot in the field that allows charged particles from the sun to dip closer to the surface than usual.
Astronomers recently observed this region is expanding and continuing to weaken, along with splitting into two lobes at which the anomaly is more debilitated – putting more technologies on our planet at risk.
The only solution at the moment is to power down satellites and telescopes that pass through the area until NASA finds better ways to protect such devices in the anomaly’s path.
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NASA is monitoring a ‘small but evolving dent’ in Earth’s magnetic field that could impact satellites and spacecraft
Earth’s magnetic field acts as a shield that repels and protects the planet from the sun’s charged particles.
However, due to the weakened area, or the SSA, some of these particles are able to sneak by that can wreak havoc on certain technologies.
The region has been expanding for nearly a decade, but recently a shift has been observed that is splitting it into two different lobes – creating different points of weakness.
NASA scientists are now monitoring the SSA to predict future changes in order to better prepare for challenges to satellites and humans in space.
Stretching from South American and to southwest Africa is the South Atlantic Anomaly (SSA), which is a weakened spot in the field that allows charged particles from the sun to dip closer to the surface than usual
Earth’s magnetic field developed from the planet’s outer core made of molten, which began to moving around 1,800 miles above the surface.
The swirling metals created electric currents that produced the magnetic field.
Geophysicist Terry Sabaka from NASA’s Goddard Space Flight Centre in Greenbelt, Maryland, said: ‘The magnetic field is actually a superposition of fields from many current sources.’
The ‘dent’ observed in the SSA is caused by, according to NASA, solar storms deforming the Van Allen Belts, which are two donut-shaped belts around the planet.
The Van Allen Belts are key to trapping particles that travel along Earth’s magnetic field lines.
The ‘dent’ observed in the SSA is caused by, according to NASA, solar storms deforming the Van Allen Belts, which are two donut-shaped belts around the planet. The Van Allen Belts are key to trapping particles that travel along Earth’s magnetic field lines
When viscous storm particles from the sun reach Earth, the Van Allen Belts become energized, which in turn deforms the magnetic field, allowing the particles to hit the atmosphere
The innermost belt begins about 400 miles from the surface of Earth, which keeps its particle radiation a healthy distance from Earth and its orbiting satellites.
However, when viscous storm particles from the sun reach Earth, the Van Allen Belts become energized, which in turn deforms the magnetic field, allowing the particles to hit the atmosphere.
Weijia Kuang, a geophysicist and mathematician in Goddard’s Geodesy and Geophysics Laboratory, said: ‘The observed SAA can be also interpreted as a consequence of weakening dominance of the dipole field in the region.’
‘More specifically, a localized field with reversed polarity grows strongly in the SAA region, thus making the field intensity very weak, weaker than that of the surrounding regions.’
Astronomers are now using observations and physics that contribute to models of Earth’s magnetic field to better prepare for future threats.
‘Even though the SAA is slow-moving, it is going through some change in morphology, so it’s also important that we keep observing it by having continued missions,’ Sabaka, Kuang, a NASA scientists, said.
‘Because that’s what helps us make models and predictions.’
SOLAR STORMS PRESENT A CLEAR DANGER TO ASTRONAUTS AND CAN DAMAGE SATELLITES
Solar storms, or solar activity, can be divided into four main components that can have impacts on Earth:
- Solar flares: A large explosion in the sun’s atmosphere. These flares are made of photons that travel out directly from the flare site. Solar flares impact Earth only when they occur on the side of the sun facing Earth.
- Coronal Mass Ejections (CME’s): Large clouds of plasma and magnetic field that erupt from the sun. These clouds can erupt in any direction, and then continue on in that direction, plowing through solar wind. These clouds only cause impacts to Earth when they’re aimed at Earth.
- High-speed solar wind streams: These come from coronal holes on the sun, which form anywhere on the sun and usually only when they are closer to the solar equator do the winds impact Earth.
- Solar energetic particles: High-energy charged particles thought to be released primarily by shocks formed at the front of coronal mass ejections and solar flares. When a CME cloud plows through solar wind, solar energetic particles can be produced and because they are charged, they follow the magnetic field lines between the Sun and Earth. Only charged particles that follow magnetic field lines that intersect Earth will have an impact.
While these may seem dangerous, astronauts are not in immediate danger of these phenomena because of the relatively low orbit of manned missions.
However, they do have to be concerned about cumulative exposure during space walks.
This photo shows the sun’s coronal holes in an x-ray image. The outer solar atmosphere, the corona, is structured by strong magnetic fields, which when closed can cause the atmosphere to suddenly and violently release bubbles or tongues of gas and magnetic fields called coronal mass ejections
The damage caused by solar storms
Solar flares can damage satellites and have an enormous financial cost.
The charged particles can also threaten airlines by disturbing Earth’s magnetic field.
Very large flares can even create currents within electricity grids and knock out energy supplies.
When Coronal Mass Ejections strike Earth they cause geomagnetic storms and enhanced aurora.
They can disrupt radio waves, GPS coordinates and overload electrical systems.
A large influx of energy could flow into high voltage power grids and permanently damage transformers.
This could shut off businesses and homes around the world.
Source: NASA – Solar Storm and Space Weather