9 Weirdest Alien Worlds We've Already Found

If you think the vast emptiness of space in unnerving from the vantage point of our cosy little solar system, then spare a thought for the lonely rogue planets wandering through interstellar space.

It's not entirely certain how, but these planets have somehow become detached from their host star and meander aimlessly through the galaxy like a lost child in a shopping mall.

Like the aforementioned lost child, they're pretty difficult to spot, unlike the lost child we can use gravitational microlensing to help us do it (well, depending on the size of the child, I suppose). 

The gravitational field of a massive object will cause spacetime, and subsequently light, to bend around it. This means that when one of these planets passes in from of a star, it briefly magnifies it, making it easier to spot.

There are some theories to suggest that these planets are actually more like a "failed star" (although that won't do anything for their self esteem), a sort of gas giant that didn't quite have enough mass to cause it to ignite. So rather that a bright, shiny, powerful star, it's a lumbering mass of gas lost in the vast wastes of space.

Cheerful.