Ladakh: Big buzz over aurora-like sighting in Ladakh skies
NEW DELHI: While reports of “northern lights” being sighted in Ladakh has created a big buzz, sources at the Hanle obserevatory said it’s likely that what appeared in the sky on the morning of April 24 was a “stable auroral red (SAR) arc”.
A SAR arc is a band of reddish light seen in the sky. Unlike auroras where various colours appear in moving patterns, SAR displays are static and monochromatic. Both appear during periods of geomagnetic activity triggered by a wave of charged matter blasted out of the Sun, but their mechanism of formation is slightly different.
“Even if it was an SAR arc that appeared in the sky here, it was a once-in-a-lifetime event,” the source at Hanle said. “In the early morning of April 24, the arc appeared in the northern horizonand was visible for a long time. Unfortunately, no one from the observatory was out at that time. So, it wasn’t seen through naked eyes. It’s recorded only in the 360-degree sky camera that is always on at the observatory”. He said: “Images on social media that night are probably fake.”
The night of April 23-24 was an incredible day for aurora-watchers across the world. A massive geomagnetic storm, measured at class four on a scale of five, triggered one of the most widespread displays of northern and southern lights (together called aurora)in 20 years, as per some reports. Auroras were seen and recorded over a huge area including Xinjiang province of China, California in the US, Stonehenge in Britain, areas in New Zealand and Australia — places where auroral sightings are very rare.
“Auroras are usually restricted to places close to the poles because that’s where charged particles from the Sun get past Earth’s magnetosphere and interact with oxygen and nitrogen in the atmosphere to create the display of lights. However, during very strong coronal mass ejectionevents, matter from the Sun may penetrate the magnetosphere and lead to aurora formation in places like Ladakh. It’s within the realm of possibility,” said Dipankar Banerjee, director of the Aryabhatta Research Institute of Observational Sciences (ARIES) at Manora Peak near Nainital.
The source at Hanle said instruments at the observatory had ruled out the possibility of the coloured light seen over Ladakh being “air glow”, an unrelated phenomenon invisible to the eye which often shows up as a region of faint colour in night sky images.
A SAR arc is a band of reddish light seen in the sky. Unlike auroras where various colours appear in moving patterns, SAR displays are static and monochromatic. Both appear during periods of geomagnetic activity triggered by a wave of charged matter blasted out of the Sun, but their mechanism of formation is slightly different.
“Even if it was an SAR arc that appeared in the sky here, it was a once-in-a-lifetime event,” the source at Hanle said. “In the early morning of April 24, the arc appeared in the northern horizonand was visible for a long time. Unfortunately, no one from the observatory was out at that time. So, it wasn’t seen through naked eyes. It’s recorded only in the 360-degree sky camera that is always on at the observatory”. He said: “Images on social media that night are probably fake.”
The night of April 23-24 was an incredible day for aurora-watchers across the world. A massive geomagnetic storm, measured at class four on a scale of five, triggered one of the most widespread displays of northern and southern lights (together called aurora)in 20 years, as per some reports. Auroras were seen and recorded over a huge area including Xinjiang province of China, California in the US, Stonehenge in Britain, areas in New Zealand and Australia — places where auroral sightings are very rare.
“Auroras are usually restricted to places close to the poles because that’s where charged particles from the Sun get past Earth’s magnetosphere and interact with oxygen and nitrogen in the atmosphere to create the display of lights. However, during very strong coronal mass ejectionevents, matter from the Sun may penetrate the magnetosphere and lead to aurora formation in places like Ladakh. It’s within the realm of possibility,” said Dipankar Banerjee, director of the Aryabhatta Research Institute of Observational Sciences (ARIES) at Manora Peak near Nainital.
The source at Hanle said instruments at the observatory had ruled out the possibility of the coloured light seen over Ladakh being “air glow”, an unrelated phenomenon invisible to the eye which often shows up as a region of faint colour in night sky images.
