Why 2026 will be a year like no other for the Sun mission in India

For Aditya-L1, India’s first solar observation mission in space, the year 2026 should not be like any other.

This is the first time that the observatory – put into orbit last year – will be able to observe the Sun when it reaches its maximum activity cycle.

According to NASA, this happens approximately every 11 years when the Sun’s magnetic poles reverse – the Earth’s equivalent would be the swapping of positions of the North and South poles.

It is a time of great turbulence. It sees the Sun move from calm to stormy and is marked by a dramatic increase in the number of solar storms and coronal mass ejections (CMEs) – huge bubbles of fire that blow out of the Sun’s outermost layer called the corona.

Made of charged particles, a CME can weigh up to a trillion kilograms and reach speeds of up to 3,000 km (1,864 miles) per second. It can head in any direction, including toward Earth. At maximum speed, it would take 15 hours for a CME to travel the 150 million kilometers of Earth-Sun distance.

“During normal or low activity periods, the Sun launches two to three CMEs per day,” says Professor R Ramesh of the Indian Institute of Astrophysics (IIA). “Next year we expect there to be at least 10 per day.”

Professor Ramesh is the principal investigator of the Visible Emission Line Coronagraph, or Velc – the largest of the seven scientific instruments on Aditya-L1 – and closely monitors and decodes the data it collects.

Studying CMEs is one of the most important scientific objectives of India’s first solar mission, he says. First, because the ejections provide an opportunity to learn more about the star at the center of our solar system, and second, because activities taking place on the Sun threaten infrastructure on Earth and in space.

CMEs rarely pose a direct threat to human life, but they affect life on Earth by causing geomagnetic storms that impact the weather in near space, where nearly 11,000 satellites are stationed, including 136 Indian ones.

“The most beautiful manifestations of a CME are the Northern Lights, which clearly illustrate that charged particles from the Sun are moving towards the Earth,” explains Professor Ramesh.

“But they can also cause all of a satellite’s electronics to malfunction, destroy power grids, and affect weather and communications satellites.”

The most powerful solar storm on record was the Carrington Event of 1859, which destroyed telegraph lines across the world. More recent events were recorded in 1989, when part of Quebec’s electricity grid was cut, leaving six million people without electricity for nine hours. In November 2015, solar activity disrupted air traffic control, causing chaos in Sweden and some other European airports.

In February 2022, NASA reported that a CME resulted in the loss of 38 commercial satellites.

Professor Ramesh says that if we are able to see what is happening on the solar corona and spot a solar storm or coronal mass ejection in real time, record its temperature at the origin and monitor its trajectory, this can serve as a warning to turn off power grids and satellites and move them out of harm’s way.

There are other solar missions that observe the Sun, but Aditya-L1 has an advantage over others, including the Solar and Heliospheric Observatory sent jointly by NASA and Esa (European Space Agency), when it comes to observing the corona.

“The Aditya-L1 coronagraph is the exact size that allows it to almost mimic the Moon, completely covering the Sun’s photosphere and allowing it an uninterrupted view of almost the entire corona 24 hours a day, 365 days a year, even during eclipses and occultations,” explains Professor Ramesh.

In other words, the coronagraph acts like an artificial Moon, blocking the Sun’s bright surface to allow scientists to continuously observe its faint outer corona – something the real Moon only does during eclipses.

Additionally, it is the only mission capable of studying flares in visible light, allowing it to measure the temperature and thermal energy of a CME – key indices that show how strong a CME would be if it were heading towards Earth, says Professor Ramesh.

To prepare for next year’s period of peak solar activity, the IIA collaborated with NASA to study data collected from one of the largest CMEs recorded so far by Aditya-L1.

It began on September 13, 2024 at 00:30 GMT, explains Professor Ramesh. Its mass was 270 million tons – the iceberg that sank the Titanic weighed 1.5 million tons, he says.

Its original temperature was 1.8 million degrees Celsius and its energy content was equivalent to 2.2 million megatons of TNT – by comparison, the Hiroshima and Nagasaki atomic bombs weighed 15 kilotons and 21 kilotons, respectively.

Although the numbers make him look incredibly tall, Professor Ramesh describes him as being of “average size”.

The asteroid that wiped out the dinosaurs on Earth weighed 100 million megatons, and during the Sun’s peak activity cycle, he says, we could see CMEs with even higher energy content.

“I consider that the CME that we evaluated occurred when the Sun was in its normal activity phase. This now constitutes the reference that we will use to evaluate what awaits us when the maximum activity cycle occurs,” he says.

“The resulting lessons will help us develop countermeasures to protect satellites in near space. They will also help us better understand near-Earth space,” he adds.

Follow BBC News India on Instagram, YouTube, Twitter And Facebook.