Sun once had 'evil twin' - and it's being blamed for wiping out dinosaurs
The Solar System once had two suns, scientists believe, and one of them may have wiped out the dinosaurs.
A theoretical physicist at the University of California and an astronomer from Harvard University have discovered that most stars are born with a 'brother' and our own Sun is likely to be no exception.
In fact, this 'evil twin', which has been dubbed Nemesis, may have been responsible for kicking an asteroid into Earth's orbit which led to the extinction of the dinosaurs.
In the 1980s, two paleontologists from the University of Chicago suggested that the regular rate of mass extinctions on Earth - every 26 million years - was caused by a mysterious extraterrestrial source. But, despite years of searching, nobody could ever find it.
Now the new study suggests that the Sun did have a companion star billions of years ago, but it probably escaped our Solar System and is now lost in the Milky Way.
The 'second Sun' would have been 17 times farther away from the Sun than Neptune, but would have been visible from Earth and would have appeared as a bright dot in the night sky.
It was suggested that while still part of the Solar System it made a pass closer to the Sun every 26 million years, triggering enhanced comet activity, and lashing Earth with a hail of meteorites which brought death and destruction to the planet.
Scientists believe Nemesis must have existed after studying a giant cloud of recently formed stars in the constellation Perseus.
The Sun's sibling most likely escaped billions of years ago, mixing with all the other stars in our region of the Milky Way galaxy, and impossible to locate.
The research was published in 'Monthly Notices' of the Royal Astronomical Society.