The Stellar Demolition Derby in the Centre of the Galaxy

This illustration shows stars orbiting close to the Milky Way's central supermassive black hole. The black hole accelerates stars nearby and sends them crashing into one another. Credit: ESO/L. Calçada/Spaceengine.org

The region near the Milky Way’s centre is dominated by the supermassive black hole that resides there. Sagittarius A*’s overwhelming gravity creates a chaotic region where tightly packed, high-speed stars crash into one another like cars in a demolition derby.

These collisions and glancing blows change the stars forever. Some become strange, stripped-down, low-mass stars, while others gain new life.

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Maybe We Don’t See Aliens Because Nobody Wants to Come Here

Artist impression of an alien civilization. Image credit: CfA

The Fermi Paradox won’t go away. It’s one of our most compelling thought experiments, and generations of scientists keep wrestling with it. The paradox pits high estimates for the number of civilizations in the galaxy against the fact that we don’t see any of those civs. It says that if rapidly expanding civilizations exist in the Milky Way, one should have arrived here in our Solar System. The fact that none have implies that none exist.

Many thinkers and scientists have addressed the Fermi Paradox and tried to come up with a reason why we don’t see any evidence of an expanding technological civilization. Life may be extraordinarily rare, and the obstacles to interstellar travel may be too challenging. It could be that simple.

But a new paper has a new answer: maybe our Solar System doesn’t offer what long-lived, rapidly expanding civilizations desire: the correct type of star.

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Stellar Flares May Not Condemn a Planet’s Habitability

An artistic rendering of a series of powerful stellar flares. New research says that flaring activity may not prevent life on exoplanets. CREDIT NASA's Goddard Space Flight Center/S. Wiessinger

Red dwarf stars are the most common kind of star in our neighbourhood, and probably in the Milky Way. Because of that, many of the Earth-like and potentially life-supporting exoplanets we’ve detected are in orbit around red dwarfs. The problem is that red dwarfs can exhibit intense flaring behaviour, much more energetic than our relatively placid Sun.

So what does that mean for the potential of those exoplanets to actually support life?

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