SPACE AGENCY SAYS CHANDRAYAAN-2 ORBITER DETECTS SOLAR PROTON EVENTS ISRO

 

Mumbai: The Indian Space Research Organisation (ISRO) announced on Wednesday that the Large Area Soft X-ray Spectrometer (CLASS), a payload on board the Chandrayaan-2 Orbiter, had discovered solar proton events (SPEs), which considerably increase radiation exposure to humans in space.

Coronal mass ejections (CMEs), a tremendous torrent of ionised material and magnetic fields that reach Earth a few days later, causing geomagnetic storms and lighting up the polar sky with auroras, were also observed by the sensor on January 18.

According to the ISRO, such multi-point measurements helps in the understanding of propagation and its impact on various planetary systems.

Solar flares are dramatic explosions that occasionally spew out energetic particles (called Solar Proton Events or SPEs) into interplanetary space when the Sun is active.

The majority of these are high-energy protons that have an influence on space systems and increase radiation exposure to astronauts. According to the space agency, they can produce ionisation on a huge scale in Earth's middle atmosphere.

Many severe solar flares are accompanied by CMEs, a tremendous stream of ionised material and magnetic fields that reach Earth a few days later, causing geomagnetic storms and auroras to light up the polar sky.

Solar flares are categorised based on their intensity. A-class is the smallest, followed by B, C, M, and X. Each letter stands for a tenfold increase in energy output. According to the ISRO, a M class flare is ten times more intense than a C-class flare and 100 times more intense than a B-class flare.

A finer scale from 1 to 9 exists within each letter class; an M2 flare is twice as strong as an M1 flare.

"Two M-class solar flares occurred recently. The M5.5 flare ejected energetic particles into interplanetary space, while the M1.5 flare was accompanied by a Coronal Mass Ejection (CME) "According to the space agency.

NASA's Geostationary Operational Environmental Satellite (GOES) satellite circling Earth witnessed the SPE incident. GOES, on the other hand, did not detect the CME.

"The Chandrayaan-2 Orbiter's Chandrayaan-2 Large Area Soft X-ray Spectrometer (CLASS) identified SPE owing to an M5.5 class solar flare that occurred on January 20, 2022," the ISRO said.

"A CME event was also observed as it went over the moon by the CLASS sensor due to an M1.5 class solar flare that occurred on January 18," it added.

CMEs move at a speed of roughly 1000 km/s and reach the Earth in about 2-3 days.

"The GOES satellite misses the signature of this event because the Earth's magnetic field shields it from such events. Chandrayaan-2, on the other side, captured the event "According to the ISRO.

"From two powerful flares on the Sun, the CLASS payload on Chandrayaan-2 witnessed both the SPE and CME events pass by," it added.

Chandrayaan-2 was launched on July 22, 2019 with the goal of landing on the Moon's South Pole. However, India's hope of being the first nation to successfully land on the lunar surface in its first attempt was shattered when the lander Vikram hard-landed on September 7, 2019.

The ISRO had previously stated that the mission had achieved 98 percent success because the orbiter was still transmitting data to the ground station.