Asia’s largest imaging Cherenkov telescope, located at an altitude of almost 4,300 metres, was inaugurated on Wednesday at Ladakh’s Hanle.

The Major Atmospheric Cherenkov Experiment (MACE) observatory, the highest of its kind of telescope in the world, has been indigenously built by the Mumbai-based Bhabha Atomic Research Centre (BARC) with support from the Electronics Corporation of India Ltd (ECIL) and other Indian industry partners.

The MACE observatory is touted to place India at the forefront of cosmic ray research globally by allowing scientists to study high-energy gamma rays. This will pave the way for deeper understanding of the universe’s most energetic events, such as supernovae, black holes, and gamma-ray bursts.

Even before its formal inauguration, the telescope produced high-quality work detecting gamma ray flares as far away as 200 million light years away.

About MACE observatory

MACE is 21 metres in diameter, 175 tonnes heavy, has reflector area of 356 sqm and 1,424 diamond-turned metallic mirror facets, 712 actuators, 1,088 photo-multiplier tubes, and 68 camera modules.

It is a lightweight construction and features high strength and temperature endurance. Reflector surface measuring over 350 square metres (sqm) comprises highly reflective diamond-turned custom-built metallic mirror facets that are required to be aligned with an accuracy of 2 mm over parabolic surface. The camera at the focal point contains a number of photomultiplier tubes mounted with specialised assembly to enhance light collection efficiency.

Ultrafast backend electronics with nanosecond digitization electronics is optimised for low-power and -temperature operations. Extreme weather conditions restrict transport to six-eight months a year and affect the availability of trained personnel on site.

How will the telescope work?

Gamma rays do not reach the Earth’s surface as they are stopped by the atmosphere. However, interaction with the atmosphere creates high-energy particles that travel faster than the speed of flight and emit Cherenkov radiation which is akin to a sonic boom. The mirrors and cameras capture these flashes and trace them back to its cosmic source.

Why Hanle?

The site has been carefully chosen for its unique scientific advantages as Hanle offers extremely low light pollution required for gamma ray observations. The longitudinal advantage of its location enables MACE to observe sources invisible to other parts of the world.

“Hanle is like heaven for gamma ray astronomers with its dark skies, low humidity and almost no air pollution,” said Dr AK Mohanty, chairman, Atomic Energy Commission and India’s nuclear chief. He said another few more gamma ray telescopes could be built here, making Hanle the go-to place for global astronomers, some with international collaboration.

Rare stable auroral red arc event in Ladakh due to solar storms, creating spectacular northern lights in high latitudes

In Ladakh, astronomers at the Hanle Dark Sky Reserve saw a red glow on the northwest horizon in the sky from about 1 am on May 11 that continued till early dawn.

“We were fortunate to witness Aurora activities on our all-sky camera during regular telescope observations,” Stanzin Norla, an engineer at the Hanle Dark Sky Reserve, told PTI.

He said a faint red glow was visible to the naked eye along the horizon and the event was captured in much detail by a DSLR camera installed at the Hanle Dark Sky Reserve.

“It streaked through the sky from about 1 am till 3:30 am,” Stanzin said, adding that the skies turned red along the horizon and to a pinkish hue later.

Dorje Angchuk, an engineer at the Indian Astronomical Observatory in Hanle, described the event as a stable auroral red arc, which was a rare occurrence over the skies at Ladakh.

“Auroras seen near the north or south poles are dynamic events. They keep changing. But the one witnessed at Ladakh was more stable. It is called the stable auroral red arc. The steady glow remained in the sky for a couple of hours”, Angchuk said.

Such events are rare at Hanle because it is located far south, Dibyendu Nandi, Head, CESSI at the Indian Institute of Science Education and Research Kolkata, told PTI.

He said the chances of such events being witnessed at places such as Hanle become higher during intense disturbances triggered by solar storms.

“These auroral red arcs are likely caused by heating of the atmosphere by electric currents that are circulating between Earth and outer space,” Mr. Nandi said.

“These ring currents get enhanced during geomagnetic disturbances induced by solar storms and thus the likelihood of observing the red auroral arcs is higher at times when we are in the midst of a severe geomagnetic storm”, he said.

The CESSI said the sun produced strong solar flares beginning on May 8, resulting in five outbursts of plasma capable of disrupting satellites in orbit and power grids here on Earth.

“We are witnessing severe Space Weather at levels we have not seen in the last two decades. It might get worse as more solar storms are expected to impact Earth or maybe just more spectacular auroras for all,” Mr. Nandi said.

The U.S.’ National Oceanic and Atmospheric Administration (NOAA) is calling this an unusual event, pointing out that the flares seem to be associated with a sunspot that’s 16 times the diameter of Earth. An extreme geomagnetic storm in 2003 took out power in Sweden and damaged power transformers in South Africa.

Rare stable auroral red arc event in Ladakh due to solar storms, creating spectacular northern lights in high latitudes

In Ladakh, astronomers at the Hanle Dark Sky Reserve saw a red glow on the northwest horizon in the sky from about 1 am on May 11 that continued till early dawn.

“We were fortunate to witness Aurora activities on our all-sky camera during regular telescope observations,” Stanzin Norla, an engineer at the Hanle Dark Sky Reserve, told PTI.

He said a faint red glow was visible to the naked eye along the horizon and the event was captured in much detail by a DSLR camera installed at the Hanle Dark Sky Reserve.

“It streaked through the sky from about 1 am till 3:30 am,” Stanzin said, adding that the skies turned red along the horizon and to a pinkish hue later.

Dorje Angchuk, an engineer at the Indian Astronomical Observatory in Hanle, described the event as a stable auroral red arc, which was a rare occurrence over the skies at Ladakh.

“Auroras seen near the north or south poles are dynamic events. They keep changing. But the one witnessed at Ladakh was more stable. It is called the stable auroral red arc. The steady glow remained in the sky for a couple of hours”, Angchuk said.

Such events are rare at Hanle because it is located far south, Dibyendu Nandi, Head, CESSI at the Indian Institute of Science Education and Research Kolkata, told PTI.

He said the chances of such events being witnessed at places such as Hanle become higher during intense disturbances triggered by solar storms.

“These auroral red arcs are likely caused by heating of the atmosphere by electric currents that are circulating between Earth and outer space,” Mr. Nandi said.

“These ring currents get enhanced during geomagnetic disturbances induced by solar storms and thus the likelihood of observing the red auroral arcs is higher at times when we are in the midst of a severe geomagnetic storm”, he said.

The CESSI said the sun produced strong solar flares beginning on May 8, resulting in five outbursts of plasma capable of disrupting satellites in orbit and power grids here on Earth.

“We are witnessing severe Space Weather at levels we have not seen in the last two decades. It might get worse as more solar storms are expected to impact Earth or maybe just more spectacular auroras for all,” Mr. Nandi said.

The U.S.’ National Oceanic and Atmospheric Administration (NOAA) is calling this an unusual event, pointing out that the flares seem to be associated with a sunspot that’s 16 times the diameter of Earth. An extreme geomagnetic storm in 2003 took out power in Sweden and damaged power transformers in South Africa.