A new study from a team of Harvard scientists could explain how the Earth became suitable for the rise of life nearly four billion years ago. According to a report from Phys.org, the star Kappa Ceti has been identified as a proxy for our own sun in its early days, offering unique insight into how the Earth’s magnetic field provided the necessary protection for life to emerge in the face of turbulent solar winds.

As it turns out, magnetism was just as important an ingredient for life as liquid water and an oxygenated atmosphere. According to the study’s lead author Jose-Dias Do Nascimento from the Harvard-Smithsonian Center for Astrophysics and the University of Rio G. do Norte in Brazil, a young planet must be sheltered from a young sun’s turbulent weather.

Kappa Ceti is just 30 light-years away from our own solar system, located in the constellation Cetus. It is stunningly similar to our own sun when it was the same age, and has a high amount of magnetic activity. The surface of the star is coated with massive sunspots, and emits a constant stream of plasma into space. The stellar wind on Kappa Ceti is 50 times stronger than that of our own sun.

The study offered a model of how this stellar wind would affect a young planet, much like Earth in its early days. They found that the Earth’s early magnetic field was similar in strength to today’s, but the magnetosphere, or range of protection provided by the Earth’s magnetic field was about one-third to one-half as large as it is in the present.

Kappa Ceti has shown evidence of “superflares,” or massive eruptions that release as much as 100 million times more energy than some of the biggest flares ever observed on our own sun. Due to the Earth’s magnetic field in its early days, the surface of the planet was protected from the strong solar winds that would have blown the atmosphere off into space.

A Harvard press release describing the details of the study can be found here.