AN Irishman is among a team of NASA scientists who set a new long-duration balloon world record in Antarctica while investigating the cause of cosmic rays.
Dr John E Ward, from Glenties in Co Donegal, eclipsed a record set by another Irishman using a balloon the size of Croke Park.
He is part of a NASA research project called Super-TIGER (Super Trans-Iron Galactic Element Recorder), which is a two-tonne instrument that collects cosmic-ray particles.
The Northern Lights are made by cosmic rays colliding with the Earth's magnetic field.
Although cosmic rays were discovered more than 100 years ago, physicists still do not know where they come from.
Dr Ward and his team are trying to show that cosmic rays come from explosions within groups of enormous stars known as OB associations.
"The balloon has circled the South Pole twice, at an altitude of around 130,000 feet. So far the team have collected more than 50 million cosmic-ray particles," said close friend, Dr Patrick Boyle.
Dr Ward's balloon flight surpassed the record of 42 days set in 2004 by another Donegal man, Jojo Boyle, from Dungloe, with the CREAM cosmic-ray project.
When the balloon is back close to McMurdo Station, it will be brought down by an explosion triggered from a NASA satellite, allowing the instrument to fall back to Earth on a parachute.