The first 'alien' comet up close: NASA reveals historic visitor from another solar system is shaped like a CIGAR
Comet C/2017 U1 was first spotted by a telescope in Hawaii on 18 October
It was then spotted 34 separate times in the week that followed
Most comets follow ellipse-shaped orbits around the sun
But this comet orbits at an angle, and does not appear to go round the sun
Experts suggest this shows that it comes from interstellar space
Solar system could be packed with 10,000 interstellar travelers at any given time
