Described in a nutshell, a coronal mass ejection (also known as a CME) is a large burst of plasma originating from the sun's upper atmosphere that gets discharged into the solar wind. CME’s are a fairly common phenomenon in our solar system. At solar max (a routine time where the sun's activity is at its maximum), they commonly occur approximately three times per day.

CME's can vary in size considerably: an international team of astronomers discovered a monstrously large one (far larger than the largest one ever observed at a sun-like star) in a star system located a little over 100 light-years away from a star named EK Draconis.

The event is a sobering warning as scientists suggest that our sun is also capable of such a dangerous action. Furthermore, the team thinks that past, similar eruptions from our own sun may have helped shape the way Earth and Mars look today!

A stunning CME as it erupts on our sun - *Image Credit: NASA/GSFC/SDO HDR tune by Universal-Sci*

In their study, astronomers spied on the star known as EK Draconis. As a G-type main-sequence star, it bears a striking resemblance to our sun. However, at 100 million years old, Draconis is a lot younger than our 4.6 billion-year-old sun. As a younger version of our sun, it gives astronomers the excellent opportunity to obtain insights into the sun's younger years.

The team followed the star for over 30 nights during the spring and winter of 2020 using the NASA Transiting Exoplanet Survey Satellite and the EIMEI Telescope from Kyoto University.

On April 5th, the team got fortuitous: all of a sudden, they were witness to a fierce cosmic fireworks show. EK Draconis produced an unprecedentedly ferocious CME, during which an immense amount of energy and charged particles were expelled.

Although the team was only able to capture the initial phase of the CME, the cloud of glowing hot plasma was clocked at a fast pace of about 378 miles per second.

The CME was also rather unique in terms of mass as the cloud had a mass of quadrillions of kilograms, which is over ten times more massive than the most powerful coronal mass ejection ever observed from a G-type main-sequence star.

Can gigantic CME's also occur in our own solar system?

According to Yuta Notsu, one of the authors of the paper, this size of CME can hypothetically also happen in our solar system. The team's findings may help further our understanding of these types of occurrences that could have influenced Mars and Earth over the past billions of years.

Luckily, observations up until this point, together with novel research, indicate that our sun may be comparatively tranquil compared to EK Draconis. A 2019 research paper published in the AStrophysical Journal, for instance, revealed that youthful sun-like stars throughout the milky way appear to experience regular superflares—akin to solar flares in our solar system but tens to or even hundreds of times as strong.

Nonetheless, scientists say a superflare and following CME can still occur in our system but not very frequently. The team estimates that such an occurrence will happen only once every several thousand years.

Planets such as Mars and Earth may have been influenced by large CME’s in the early solar system - *Image Credit: joshimerbin via Shutterstock/HDR tune by Universal-Sci*

Influence on the early solar system

Notsu stated that giant CME's may have been a lot more commonplace at the time when our solar system was still in its infancy.

In fact: "The atmosphere of present-day Mars is very thin compared to Earth's," Notsu said. "In the past, we think that Mars had a much thicker atmosphere. Coronal mass ejections may help us to understand what happened to the planet over billions of years."

All in all, early giant CME's may have played a significant role in shaping Mars and the Earth to the planets as we know them. We suspect that future research will shine a light on a lot of mysteries about the early solar system.

In the meantime, be sure to check out the team's paper published in Nature Astronomy listed below if you are interested in more details.

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