Indian scientists report Aditya-L1’s ‘first major result’ – What is it and why is it important for Earth and space
Scientists in India have reported the “first significant result” from Aditya-L1, the country’s first solar observation mission in space.
The new knowledge, they said, could help keep power grids and communications satellites out of harm’s way the next time solar activity threatens infrastructure on Earth and in space, the BBC reports.
On July 16, the most important of Aditya-L1’s seven science instruments – the Visible Emission Line Coronagraph, or Velc – recorded data that helped scientists estimate the exact start time of a coronal mass emission (CME).
The study of CMEs—massive fireballs ejected from the Sun’s outermost coronal layer—is one of the most important scientific goals of India’s maiden solar mission.
“Consisting of energetic particles, a CME could weigh up to a trillion kilograms and can reach speeds of up to 3,000 km [1.864 μίλια] per second while traveling. It can be pointed in any direction, including Earth,” says Prof R Ramesh of the Indian Institute of Astrophysics who designed Velc.
“Now imagine this huge fireball ‘rushing’ towards Earth. At its top speed, it would take only about 15 hours to cover the Earth-Sun distance of 150 million kilometers.”
The coronal ejection recorded by Velc on July 16 had begun at 13:08 GMT. Velc principal investigator Professor Ramesh, who has published a paper on this CME in the prestigious Astrophysical Journal Letters, said it came from the Earth side.
“But within half an hour of the course, it deviated and went in a different direction, going behind the Sun. Because it was so far away, it didn’t affect Earth’s weather.”
However, solar storms, solar flares, and coronal mass ejections commonly affect Earth’s weather. They also affect space weather where nearly 7,800 satellites are stationed, including more than 50 from India.
According to Space.com, they rarely pose a direct threat to human life, but they can wreak havoc on Earth interfering with the Earth’s magnetic field.
Their more benign impact causes beautiful auroras in places near the North and South Poles. A stronger coronal mass emission can cause the aurora to appear in more distant skies, such as in London or France – as it did in May and October.
But the impact is much more severe in space where the charged particles of a coronal mass emission can cause all of a satellite’s electronics to malfunction. They can bring down power grids and affect weather and communications satellites.
“Today our lives are completely dependent on communication satellites and CMEs can affect the internet, telephone lines and radio communication”says Professor Ramesh. “This can lead to absolute chaos.”
The most powerful solar storm in recorded history occurred in 1859. Dubbed the Carrington Event, it triggered intense aurora emissions and knocked out telegraph lines across the globe.
NASA scientists say a similarly powerful storm hit Earth in 2012 and was “just as dangerous”. They say we were “incredibly lucky” that instead of hitting our planet, the storm cloud hit NASA’s STEREO-A solar observatory in space.
In 1989, a coronal mass ejection “knocked out” part of Quebec’s power grid for 9 hours, leaving 6 million people without power.
And on November 4, 2015, solar activity disrupted air traffic control in Sweden and some other European airports, leading to travel chaos for hours.
Scientists report that if we are able to see what is happening on the Sun and detect a solar storm or coronal mass emission in real time and track its trajectory, it can act as a forecast to turn off networks and satellites and keep them away from anything that might affect them.
The US space agency Nasa, the European Space Agency (ESA), Japan and China have been monitoring the Sun through their solar missions in space for decades. With Aditya-L1 – named after the Hindu Sun God – Indian space agency Isro joined this select group earlier this year.
From its vantage point in space, Aditya-L1 is able to continuously monitor the Sun, even during eclipses, and conduct scientific studies.
Professor Ramesh says that when we look at the Sun from Earth, we see an orange ball of fire which is the photosphere – the surface of the Sun or the brightest part of the star.
Only during a total eclipse, when the Moon passes between the Earth and the Sun and covers the photosphere, can we see the solar corona, the outermost layer of the Sun.
India’s coronagraph, says Professor Ramesh, has a slight advantage over the coronagraph on the Nasa-ESA joint Solar and Heliospheric Observatory.
“Ours is of a size that can mimic the role of the Moon and artificially obscure the Sun’s photosphere, giving Aditya-L1 an uninterrupted view of the solar corona 24 hours a day 365 days a year.”
The Nasa-ESA mission’s coronagraph, he says, is larger which means it obscures not only the photosphere but also parts of the solar corona – so it can’t see the genesis of a CME if it comes from the hidden region.
“But with Velc, we can precisely estimate when a coronal mass emission starts and in which direction it is headed.”
India also has three ground-based observatories – at Kodaikanal, Gauribidanur in the south and Udaipur in the northwest – to look at the Sun. So if we add their findings with those of Aditya-L1, we can greatly improve our understanding of the Sun, he adds.
Source :Skai
I am Terrance Carlson, author at News Bulletin 247. I mostly cover technology news and I have been working in this field for a long time. I have a lot of experience and I am highly knowledgeable in this area. I am a very reliable source of information and I always make sure to provide accurate news to my readers.