Nasa has observed a huge and powerful new type of explosion above the sun’s superheated surface.
The face of our star is a roiling hellscape where temperatures soar to 5,500 degrees celsius.
Huge flares known as ‘prominences’ often gush out of the sun before falling back onto the solar surface.
But a team working as part of Nasa’s Solar Dynamics Observatory saw a prominence loop back to the sun before running into a ‘snarl of magnetic field’ and causing a huge magnetic explosion.
Scientists have previously observed the ‘the explosive snap and realignment of tangled magnetic field lines on the sun’ – a process known as magnetic reconnection.
During the latest observation, this process was triggered by the explosion – the first time this has ever been seen.
It’s hoped that by understanding a little more about how the process of magnetic reconnection works we can better predict ‘space weather’ – bursts of solar radiation that can damage satellites around Earth.
The sun is currently going through a period in its 11-year cycle called the solar minimum, which means sunspot activity has slowed and its face has gone blank.
Normally, the sun protects our solar system from cosmic rays – which are deadly beams of particles which shoot through space.
But when the sun reaches solar minimum, its magnetic field weakens and allows more rays to pour into our star system.
This doesn’t tend to pose a threat to anyone here on Earth, but it’s risky for astronauts and satellites outside our atmosphere.
Scientists use balloons to measure the strength of cosmic rays as they smash into Earth’s atmosphere.
The ‘Space Age record’ for cosmic rays was set in 2009/ 2010 during the last solar minimum, but experts believe we could be about to see even more powerful beams hit our planet.
‘A new record could be just weeks or months away,’ wrote Dr Tony Phillips.
‘Who cares? Anyone who steps on an aeroplane.
‘Cosmic rays penetrate commercial jets, delivering whole-body dosages equal to one or more dental X-rays even on regular flights across the USA. Cosmic rays pose an even greater hazard to astronauts, of course.
‘Cosmic rays can also alter the electro-chemistry of Earth’s upper atmosphere and are thought to play some role in sparking lightning.’
This solar slowdown often causes temporary cooling in Earth’s atmosphere
Climate change deniers often hail this cooling as evidence that the heating of our world is about to go into reverse.
Sadly, this is very unlikely to be true because the sun follows an 11-year cycle, meaning it will simply spring back to life in the coming years.
However, once activity ramps up, the sun will be rocked by an increased number of gigantic ‘monster’ explosions, Nasa warned earlier this year.
Eruptions from the face of our star are called ‘prominences’ and cause vast amounts of superhot gas to shoot into space, often forming beautiful loops on the solar surface.
During the solar minimum, the number of flares and sunspots is dramatically reduced.
When the sun leaps back from its minimum after roughly 11 years, we’re likely to see more and more ferocious explosions on the sun.
Nasa warned: ‘After our Sun passes the current Solar Minimum, solar activity like eruptive prominences are expected to become more common over the next few years.’
The space agency released dramatic pictures of a ‘monster’ solar prominence recording by its Solar Dynamic Observatory in 2011, which shows what we should expect to see when the sun’s minimum reaches its end.
It wrote: ‘The dramatic explosion was captured in ultraviolet light in the featured time lapse video covering 90 minutes, where a new frame was taken every 24 seconds.
‘The scale of the prominence is huge – the entire Earth would easily fit under the flowing curtain of hot gas. A solar prominence is channelled and sometimes held above the Sun’s surface by the Sun’s magnetic field.
‘A quiescent prominence typically lasts about a month, and may erupt in a Coronal Mass Ejection (CME) expelling hot gas into the Solar System. The energy mechanism that creates a solar prominence is still a topic of research.’
A prominence is not necessarily a threat to Earth, because they tend to loop into space and then fall back into the sun.
But sometimes they can cause a ‘Coronal Mass Ejection’ which causes billions of tons of particles to gush outwards at high speed.
These eruptions are generally only strong enough to cause problems for communications satellites or other spacecraft.
Sometimes, however, they are much stronger and could be powerful enough to ‘impair’ human civilisation, Nasa warned earlier this year.
The most famous Coronal Mass Ejection occurred in 1859 and caused a geomagnetic storm called the ‘Carrington Event’ as a pulse of charged particles bombarded Earth’s magnetosphere.
If this happened today, the results would be devastating.
In April, Nasa wrote: ‘The Carrington Event compressed the Earth’s magnetic field so violently that currents were created in telegraph wires so great that many wires sparked and gave telegraph operators shocks.
‘Were a Carrington-class event to impact the Earth today, speculation holds that damage might occur to global power grids and electronics on a scale never yet experienced.’
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