London, Oct 19 : Sun's protective 'bubble', which helps to shield the Earth from harmful interstellar radiation, is shrinking and getting weaker, claim NASA scientists.
NASA scientists are set to study the heliosphere, the protective bubble around the sun, to understand why it is shrinking. According to new data, the protective shield of energy that surrounds our solar system, has weakened by 25 per cent over the past decade and is now at it lowest level since the space race began 50 years ago.
Now, in order to find out the reason, the Interstellar Boundary Explorer, or IBEX, will be launched from an aircraft today on a Pegasus rocket into an orbit 150,000 miles above the Earth, where it will 'listen' for the shock wave that forms as our solar system meets the interstellar radiation.
"The interstellar medium, which is part of the galaxy as a whole, is actually quite a harsh environment. There is a very high energy galactic radiation that is dangerous to living things," the Telegraph quoted Dr Nathan Schwadron, co-investigator on the IBEX mission at Boston University, as saying.
"Around 90 per cent of the galactic cosmic radiation is deflected by our heliosphere, so the boundary protects us from this harsh galactic environment," Schwadron added.
The heliosphere is created by the solar wind, a combination of electrically charged particles and magnetic fields that emanate a more than a million miles an hour from the sun, meet the intergalactic gas that fills the gaps in space between solar systems.
At the boundary where they meet a shock wave is formed that deflects interstellar radiation around the solar system as it travels through the galaxy.
The scientists hope the IBEX mission will enable them to gain a better understanding of what happens at this boundary and help them predict what protection it will offer in the future.
Without the heliosphere, the harmful intergalactic cosmic radiation would make life on Earth almost impossible by destroying DNA and making the climate uninhabitable.
If the heliosphere continues to weaken, scientists fear that the amount of cosmic radiation reaching the inner parts of our solar system, including Earth, will increase.
This could result in growing levels of disruption to electrical equipment, damage satellites and potentially even harm life on Earth.