There is a wild theory out there regarding our sun. This theory revolves around the fact that our star, has an evil twin called Nemesis orbiting some 1.5 light years away. This theory came about after some scientists in the 1980’s realized that mass extinctions based on fossil records happened fairly regularly every 26 million years.
They identified 12 such extinctions all throughout our planet’s history. Like the dinosaur extinction some 65 million years ago, these remaining 11 mass extinctions are believed to have all been caused by impacting asteroids and comets hurling towards Earth at regular intervals. The reasoning behind such predictable timetables is believed by some to be another, smaller star revolving around our sun.
While this seems highly unlikely, given the fact that we haven’t seen it yet -especially because it’s a star and not a planet or large asteroid-, these scientists say that if this hypothetical star is small enough -100 times smaller than the sun- and dim enough, it will be very difficult to see. Space is huge after all. If this heavenly body would be classified as a brown or white dwarf star and we didn’t know where to look exactly, it would be very difficult to discover.
But what makes this “evil”, hypothetical star be the cause for all of these extinctions? Well, our solar system is surrounded on all sides by a veil of comets, commonly known as the Oort Cloud. This cloud is way outside into the outskirts, much further than even Pluto. And when Nemesis journeys back towards the sun, it brings with it many of these comets, flinging them in all directions within the inner solar system.
Given the fact that over 70% of all stars within the observable universe have twins, statistically speaking, this theory has a lot of backing. Moreover, astronomers have found a dwarf planet within this Oort Cloud -around 1 light year away from the Sun- called Sedna which has a highly elliptical orbit of 12,000 years around the our star. Scientists believe that this extremely elongated orbit was caused by a big gravitational pull relatively close by, like a dwarf star.
Nevertheless, some attention has been given to this theory and even if a solar companion may be hard to find, it would still be visible by sensitive telescopes. Astronomers have scoured the sky using the Two Micron All Sky Survey (2MASS), which studied the sky over four years in three infrared wavelengths. The instrument discovered 173 brown dwarfs farther away than our solar system, but none near enough to be the infamous Nemesis.
While the Sun’s evil twin still remains a theory and may not be the cause for all of those previous mass extinctions, we still have to keep in mind that :
“The dinosaurs became extinct because they didn’t have a space program. And if we become extinct because we don’t have a space program, it’ll serve us right!” –Larry Niven