Washington:
A new NASA study has made some interesting revelations about life on our planet Earth. According to the study, some powerful solar explosions occurred four billion years ago on the young Sun and they may have the source of crucial energy that was needed to provide warmth to the Earth and create complex molecules that are necessary for life, despite the Sun’s faintness. In order to trace the origins of life on Earth and search for life on other planets, it is important to understand the conditions that were necessary for life on our planet.
The fact that the young Sun was not luminous enough to warm the Earth has been hindering mapping evolution until now. The Sun had only about three-quarters the brightness some four billion years ago compared to what it has today. But giant eruptions on its surface spewed enormous amounts of solar material and radiation out into space. The new findings suggest, these powerful solar explosions may have provided the energy that was required to warm the Earth.
Also, the simple molecules that were turned into complex molecules necessary for life such as RNA and DNA may have been the result of the energy from the solar flares. “Back then, Earth received only about 70 per cent of the energy from the Sun than it does today,” said Vladimir Airapetian, from NASA’s Goddard Space Flight Centre in US.
“That means Earth should have been an icy ball. Instead, geological evidence says it was a warm globe with liquid water,” said Airapetian. “Our new research shows that solar storms could have been central to warming Earth,” he said. In order to piece together the history of Sun, scientists have been searching for similar stars in the galaxy. The stars appear as a functional timeline of how our own Sun evolved when the Sun-like stars are placed in order according to their age.
Hence, the scientists are able to ascertain that the Sun was fainter some 4 billion years ago. Studies have also revealed that the young stars frequently produce powerful flares similar to the ones we witness on the Sun today. Solar flares, that are often accompanied by huge clouds of solar material, called coronal mass ejections (CME), which erupt out into space, are defined as giant bursts of light and radiation.
The current strong magnetic field of the Earth helps keep the bulk of the energy from such space weather from reaching the planet. Earth when young had a weaker magnetic field and had much wider footprint near the poles. “Our calculations show that you would have regularly seen auroras all the way down in South Carolina,” said Airapetian.
“And as the particles from the space weather travelled down the magnetic field lines, they would have slammed into abundant nitrogen molecules in the atmosphere,” he said. “Changing the atmosphere’s chemistry turns out to have made all the difference for life on Earth,” he added. This study was published in the journal Nature Geoscience.
