NASA thinks wild solar storms four billion years ago created conditions for life on Earth

IN A breakthrough finding that will help us search for alien life, NASA thinks it just solved what’s known as the Faint Young Star Paradox.

NASA scientists think they have discovered the key to the origin of life on Earth.

Astronomers at the US space agency believe wild solar storms produced by the volatility of our planet’s young Sun around four billion years ago could have provided the energy required to kickstart life on Earth.

Juvenile stars can be exceedingly violent and our Sun’s early days were no exception. About four billion years ago its surface bubbled with eruptions that spewed particle clouds of solar material and radiation into space. It’s believed these solar storms, known as superflares, penetrated the Earth’s protective magnetic field (the magnetosphere), which was weaker at the time.

The active Sun particles then interacted with the nitrogen rich atmosphere around Earth which created a greenhouse effect, causing the planet to warm and allowing the chemical conditions for life to develop.

“This is a huge step forward in understanding our earliest years, and potentially resolves a mystery going back nearly half a century,” Astronomer Alan Duffy told news.com.au.

AN ANSWER TO A LONG HELD PARADOX

Nearly four billion years ago the Sun’s heat was thought to be just 70 per cent of what it is today, and the findings provide a neat answer for what has been called the “faint young star paradox”.

The paradox was first put forth by Carl Sagan and George Mullen in 1972 after they discovered signs of liquid water on Earth around four billion years ago.

The paradox describes the apparent contradiction between evidence of liquid water early in Earth’s history and the insufficient heat provided by the Sun at the time to produce such a result.

“Back then, Earth received only about 70 per cent of the energy from the sun than it does today,” lead author Vladimir Airapetian said in a statement on NASA’s website.

“That means Earth should have been an icy ball. Instead, geological evidence says it was a warm globe with liquid water. We call this the Faint Young Sun Paradox. Our new research shows that solar storms could have been central to warming Earth.”

Today, Earth would only experience such large solar storms about once a century or less, Duffy said. But data collected by NASA’s keplar telescope shows that young stars can produce as many as 10 superflares a day.

A NASA image of the Sun particles penetrating the Earth’s magnetic field.

THE PERFECT STORM

When the Sun was just a baby star, the Eath’s atmosphere was 90 per cent nitrogen, 12 per cent higher than modern levels. According to the NASA study, the active particles that spewed from the Sun collided with nitrogen molecules causing them to breakdown into individual nitrogen atoms. The atoms then collided with carbon dioxide which produced carbon monoxide and oxygen.

“As the particles from the space weather travelled down the magnetic field lines, they would have slammed into abundant nitrogen molecules in the atmosphere. Changing the atmosphere’s chemistry turns out to have made all the difference for life on Earth,” Airapetian said.

The greenhouse hypothesis has long been suggested as a way to solve the paradox but the latest findings by NASA are particularly neat because “it also provides a chemical building block for life just when we need it in terms of Earth’s history,” Duffy said.

THE SEARCH FOR ALIEN LIFE

NASA said the findings, which were published in the journal Nature Geoscience on Monday, will help guide the search for life on other planets.

Mr Duffy said the new data will mean we can be more selective and ultimately more efficient in our search for alien life.

“If this is indeed the key to how life started on Earth it means we can be pickier about the worlds we spend time exploring as we know they have to have a specific combination of planetary magnetic field and age of their star,” he said.

“However I would also argue that it probably means life can arise on worlds that we might previously have thought would be too cold based on how bright their star is and the planet’s distance from it.”

Earlier this month, NASA’s keplar mission announced nine newly discovered planets that it thought were potentially habitable. This latest research will further aid astronomers in their pursuit to find planets that are conducive to life.

“Something this big will take years to fully understand but it’s given us another piece of the puzzle to search for potentially life sustaining worlds,” Alan Duffy said.

This image provided by NASA shows a solar flare captured by the Solar Dynamics Observatory in 2012.