New sunspots on the surface of the Sun and the biggest solar flare since 2017 could be a sign that our star is waking up from a long slumber, according to NASA.
The NASA Solar Dynamics Observatory (SDO) spotted the ‘strongest flare since October 2017’ on May 29, suggesting it may be entering a new solar cycle.
A solar flare is a burst of radiation coming from sunspots – relatively cool patches on the surface of the Sun – and NASA says there’s also an increase in sunspot activity.
The flare poses no danger to Earth as it wasn’t aimed at our planet – but NASA says it is a sign of the star moving to a more active phase of its 11-year cycle.
The flares were too weak to pass the threshold at which the Space Weather Prediction Center would trigger an alert to scientists on Earth, NASA said.
After several months of very few sunspots and little solar activity, scientists and space weather forecasters are keeping their eye on this new cluster to see whether they grow or quickly disappear.
According to NASA ‘the sunspots may well be harbingers of the Sun’s solar cycle ramping up and becoming more active.’
Whether they are just a temporary change or a move to a new more active phase won’t be known for a few months months, NASA said.
‘It takes at least six months of solar observations and sunspot-counting after a minimum to know when it’s occurred,’ the space agency wrote on its website.
‘Because that minimum is defined by the lowest number of sunspots in a cycle, scientists need to see the numbers consistently rising before they can determine when exactly they were at the bottom.’
It means that solar minimum is only recognisable after the fact – you can’t say ‘we’re currently in solar minimum’ as it takes up to 12 months to confirm – by which point we would be out of solar minimum.
During its 11-year cycle activity from the Sun rises and falls, sunspots also rise and fall in number – these sunspots are tracked by NASA and other agencies.
By tracking the sunspots they are able to determine and predict the progress of the solar cycle and solar activity coming towards the Earth.
‘Currently, scientists are paying close attention to the sunspot number as it’s key to determining the dates of solar minimum,’ NASA wrote.