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When Our Cosmic Neighbor Betelgeuse Goes Supernova, Will It Threaten All Life On Earth?

Betelgeuse, an 8.5 million-year-old bright reddish star located in the Orion constellation, has been fainting, or getting dimmer, for some time now.

betelgeuse orion constellation
Betelgeuse’s location in the Orion constellation (left side).

Up until recently, the fading has been somewhat steady, but earlier this month scientists detected a dramatic change which prompted them to believe the red giant may be entering a “pre-supernova phase” which will inevitably result in its collapse into a blazing supernova explosion that could span over a dozen solar masses and affect neighboring systems, such as our own.

A hypothetical Betelgeuse supernova could be the most spectacular event ever witnessed by humanity, being up to 20 times brighter than the full moon and easily visible in broad daylight. Contrary to pop culture belief, events such as these last anywhere from several weeks to several years; they are not over in a mere few seconds to minutes.¹

Space.com reports at 642.5 light-years from Earth, it would be the closest supernova observed and recorded by humans (closer than the Crab Nebula, which is 6,523 light-years from Earth and is the result of a supernova reported to have taken place in A.D.1054). This also means that if we see Betelgeuse explode tonight, the supernova really would have taken place over 600 years ago.

crab nebula
The Crab Nebula as observed using the FORS2 instrument on the morning of November 10, 1999. (Credit: European Southern Observatory)

Since the star is more than 10 light years away from us, Betelgeuse’s supernova most likely would not directly “roast” the Earth or any other planets in our Solar System.

While the Earth is believed to be unaffected by such an event, the outer solar system might be a different story as the heliosphere (the border where solar winds meet interstellar space, which is believed to be about 60 AU from the Sun or twice that of Pluto’s orbit) may be briefly pushed inward; as far in as the orbit of Saturn. In the aforementioned circumstance, the outer planets may develop spectacular auroras on their poles, possibly with characteristics never seen before.²

Supernovae occur about once every 50 years in a galaxy the size of the Milky Way and are often visible to the naked eye from tens of thousands of light years away.³

Read more:

Betelgeuse is Continuing to Dim! It’s Down to 1.506 Magnitude

This Is What We’ll See When Betelgeuse Really Does Go Supernova

Main Image Credit: James Stone / Moment / Getty Images

Additional sources: 1 2 3


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