Second sun approaching
A star is hurtling towards us from the constellation of Swan. One day it will visit us for a cosmic while and hurl comets towards Earth.
The Earth is getting a second sun. This is the conclusion of Austrian astronomers based on data from the European Gaia space telescope, which creates a precise 3D map of celestial bodies. According to the data, a star called Gliese 710 from the constellation Swan is hurtling towards the outer reaches of our solar system at a speed of 50,000 km/h. Gliese 710 is currently still 60 light years away, but in just 1.29 million years the star will have come within a few light weeks of Earth. That could be uncomfortable.
This is because our second sun will enter the Oort Cloud, which is thought to be at the edge of our solar system. There should be a lot going on there: comets, asteroids and perhaps a tenth planet. The gravitational force of the migrating star will change the orbits of countless other celestial bodies, which in turn will result in collisions and thus new celestial bodies. Gliese 710 alone will divert 100 million comets from their orbits, a research team led by Austrian astronomers Elke Pilat-Lohinger and Thomas Maindl has calculated.
Around 4,500 of these comets will then be hurled towards the interior of our solar system. This significantly increases the risk of an impact on Earth. Such an impact would be "comparable to the asteroid impact at the end of the Cretaceous period, which led to the extinction of the dinosaurs", Pilat-Lohinger told ORF. The calculations are enormously complex and necessarily incomplete because there is no complete inventory of the (as yet unproven) Oort Cloud, and certainly not of its exact state in 1.3 million years.
Just visiting
Astronomers can only estimate how close the star will come to us, as there are many unknowns involved. They say it will probably be between 4300 and 13366 astronomical units (AU). One AU is not quite 150 million kilometers. This means that Gliese 710 will be visible from Earth with the naked eye, just like the planet Jupiter is now.
However, the star will not stay with us, but will leave the Oort Cloud some 64,000 years after its arrival and move on. heise online will report.
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