Nasa has warned that the sun's activity is escalating far beyond scientists' predictions, leading to more solar storms, flares and space weather events. Solar activity typically follows an 11-year cycle, with strength declining between the 1980s and 2008. Scientists had expected this trend to continue, but a new study shows the sun has been increasingly active since 2008.
'All signs were pointing to the sun going into a prolonged phase of low activity,' said Jamie Jasinski of Nasa's Jet Propulsion Laboratory, who led the study. 'So it was a surprise to see that trend reversed. The sun is slowly waking up.' The findings were published in The Astrophysical Journal Letters.
Increased solar activity can disrupt communication systems on Earth, with coronal mass ejections and solar flares causing radio blackouts, damage to satellites, GPS errors and power grid failures. Charged particles can also disturb the atmosphere and magnetic field, producing strong auroras.
Astronomers have tracked solar activity since the 1600s. One of the longest anomalous periods occurred between 1790 and 1830, when the sun was quiet. 'We don't really know why the sun went through a 40-year minimum starting in 1790,' Dr Jasinski said. 'The longer-term trends are a lot less predictable.'
Next week, Nasa plans to launch two new missions – the Carruthers Geocorona Observatory and Interstellar Mapping and Acceleration Probe – to further space weather research. The findings will inform how space weather could affect spacecraft and astronauts ahead of the Artemis campaign to return humans to the Moon.
