The world's largest and most sensitive cosmic ray monitor has identified a burst of galactic cosmic rays indicating a potential crack in the Earth's magnetic shield, a new study revealed.

According to scientists, the cosmic-ray detector located in India revealed weakness in the Earth's magnetic shield after a giant cloud of plasma ejected from the sun's corona hit Earth at a speed of about 2.5 million kilometers per hour.

It caused heavy compression of the Earth's magnetosphere, from 11 to four times the radius of Earth, allowing dangerous lower energy galactic cosmic ray particles to enter our atmosphere and triggering a severe geomagnetic storm on 22 June 2015.

It was one of the largest geomagnetic storms in recent past, creating an intense aurora borealis and radio signal blackouts  among the most northern latitude countries, according to the research study published in the journal Physical Review Letters this week

The burst of galactic cosmic rays of about 20 GeV, which lasted for about two hours, was detected by GRAPES-3 muon telescope situated in southern India at Tata Institute of Fundamental Research's Cosmic Ray Laboratory in Ooty in Tamil Nadu. The GRAPES-3 is a collective effort among scientific institutes from Japan and India.

Mathematical simulations conducted by the GRAPES-3 researchers, including Pravata K Mohanty, showed that the Earth's magnetic protection fractured briefly due to the occurrence of magnetic reconnection.

It might not be something we take too seriously. However, we should be thankful of the Earth's magnetosphere which stretches over a radius of a million kilometers. It acts as the primary line of defense, shielding us from the constant flow of solar and galactic cosmic rays, harmful high-intensity energetic radiation, charged particles, and meteorites thus protecting life on our planet.

The crack indicates that Earth's magnetic shield is weakening. If this continues, it could cause widespread havoc on Earth including thwarting power systems and leaving plant and animal life vulnerable to ultraviolet radiation.