NASA launched the Hubble Spcae Telescope 21 years ago and since then it has taken tens of thousands of photographs. The images produced has enlightened astronomers on how our universe works, as well as dazzled anyone who looks at them.

The universe is a truly amazing, beautiful place, and Hubble has captured images as diverse and spectacular as galaxy collisions across space and time.

Scientists are continually learning new information about the cosmos, largely thanks to Hubble and similar initiatives. Recently, Hubble captured an image of the  Necklace Nebula, a dying binary star 15,000 light-years away from Earth.

About 10,000 years ago one of the aging stars ballooned to the point where it engulfed its companion star, NASA said on its website. The smaller star continued orbiting inside its larger companion, increasing the giant's rotation rate. 

The bloated companion star spun so fast that a large part of its gaseous envelope expanded into space. Due to centrifugal force, most of the gas escaped along the star's equator, producing a ring. The embedded bright knots are dense gas clumps in the ring.

Last week, astromers found a distant planet that is darker than any substance found on Earth. The Jupiter-sized gas giant reflects only one percent of the sunlight that hits it.