<p> Warning signs of a type of space weather event can be detected much earlier than with current forecasting techniques - providing critical extra time that could help protect astronauts, NASA scientists sa</p>.<p>y.<br /><br />The Sun sometimes erupts with bursts of light, solar material, or ultra-fast energised particles - collectively, these events contribute to space weather.<br /><br />Earth's magnetic field and atmosphere protect us on the ground from most of the harmful effects of space weather, but astronauts in low-Earth orbit - or even, one day, in interplanetary space - are more exposed to space weather, including bursts of fast-moving particles called solar energetic particles, or SEPs.<br /><br />"Robotic spacecraft are usually radiation-hardened to protect against these kinds of events. But humans are still susceptible," said Chris St Cyr, a space scientist at NASA's Goddard Space Flight Centre in the US.<br /><br />NASA wants to help improve systems that would provide future astronauts with advance warning of incoming SEPs<br /><br />Scientists from NASA and the National Centre for Atmospheric Research in Boulder, US showed that tracking an associated kind of solar explosion - fast-moving clouds of magnetic solar material, called coronal mass ejections - can help.<br /><br />They observe coronal mass ejections using a type of instrument called a coronagraph, in which a solid disk blocks the Sun's bright face, revealing the Sun's tenuous atmosphere, called the corona.<br /><br />Space-based coronagraphs are more widely used in space weather research because of their wide-field solar views that are not interrupted by cloud cover or Earth's rotation.<br /><br />However, ground-based coronagraphs have their own advantages - while they can only observe the Sun in the day during clear weather, they can return data almost instantly, and at a much higher time resolution than satellite instruments.<br /><br />This speed of data return could make a significant difference, given that SEPs can move at nearly the speed of light - so their total travel time can be less than an hour from the time they are accelerated near the sun to when they reach Earth.<br /><br />"With space-based coronagraphs, we get images back every 20-30 minutes," said St Cyr.<br />Scientists worked backwards to see whether they could use a ground-based coronagraph to get that key information on the CME's speed fast enough to lengthen the warning time.<br /><br />Their search confirmed that the necessary information to predict the arrival of the energetic particles was available about 45 minutes before the particles arrived at Earth - tens of minutes before they left the Sun's inner atmosphere.</p>
<p> Warning signs of a type of space weather event can be detected much earlier than with current forecasting techniques - providing critical extra time that could help protect astronauts, NASA scientists sa</p>.<p>y.<br /><br />The Sun sometimes erupts with bursts of light, solar material, or ultra-fast energised particles - collectively, these events contribute to space weather.<br /><br />Earth's magnetic field and atmosphere protect us on the ground from most of the harmful effects of space weather, but astronauts in low-Earth orbit - or even, one day, in interplanetary space - are more exposed to space weather, including bursts of fast-moving particles called solar energetic particles, or SEPs.<br /><br />"Robotic spacecraft are usually radiation-hardened to protect against these kinds of events. But humans are still susceptible," said Chris St Cyr, a space scientist at NASA's Goddard Space Flight Centre in the US.<br /><br />NASA wants to help improve systems that would provide future astronauts with advance warning of incoming SEPs<br /><br />Scientists from NASA and the National Centre for Atmospheric Research in Boulder, US showed that tracking an associated kind of solar explosion - fast-moving clouds of magnetic solar material, called coronal mass ejections - can help.<br /><br />They observe coronal mass ejections using a type of instrument called a coronagraph, in which a solid disk blocks the Sun's bright face, revealing the Sun's tenuous atmosphere, called the corona.<br /><br />Space-based coronagraphs are more widely used in space weather research because of their wide-field solar views that are not interrupted by cloud cover or Earth's rotation.<br /><br />However, ground-based coronagraphs have their own advantages - while they can only observe the Sun in the day during clear weather, they can return data almost instantly, and at a much higher time resolution than satellite instruments.<br /><br />This speed of data return could make a significant difference, given that SEPs can move at nearly the speed of light - so their total travel time can be less than an hour from the time they are accelerated near the sun to when they reach Earth.<br /><br />"With space-based coronagraphs, we get images back every 20-30 minutes," said St Cyr.<br />Scientists worked backwards to see whether they could use a ground-based coronagraph to get that key information on the CME's speed fast enough to lengthen the warning time.<br /><br />Their search confirmed that the necessary information to predict the arrival of the energetic particles was available about 45 minutes before the particles arrived at Earth - tens of minutes before they left the Sun's inner atmosphere.</p>