What is '10 Year Challenge' and why is it trending on social media?

There is a new trend we have seen picking up on social media lately with people posting their pictures with hashtag #10yearchallenge.

Users on Instagram, Facebook  and Twitter are posting two side by side photos of them ten years part. 

In some cases people have chosen to post single throwback photos.

From film stars to news anchors to activists, everybody seems to be enjoying the new trend, with followers posting interesting comments about how people looked ten years ago.

Instagram alone has seen over 100 million posts with hashtag #10yearchallenge 

Here is a collection of some posts:-