Female scientists and engineers around the world have put their weight behind a #GirlsWithToys campaign on Twitter, in response to a casually sexist comment made by a leading astronomer.

Shrinivas Kulkarni, a planetary science professor at the California Institute of Technology, referred to scientists as "boys with toys" in an interview with US media outlet NPR.

"We astronomers are supposed to say, 'We wonder about the stars and we really want to think about it,'" Kulkarni said.

"Many scientists, I think, secretly are what I call 'boys with toys'. I really like playing around with telescopes. It's just not fashionable to admit it."

His remarks understandably dismayed people who have campaign hard to increase the visibility of women in STEM (science, technology, engineering, and mathematics) fields, and blow away the stereotype that these are predominantly male arenas of interest.

But rather than get annoyed, prominent academics and researchers got behind a #GirlsWithToys hashtag to broadcast the incredible work that they do - often with big and vastly complicated 'toys'.

Female scientists react to 'boys with toys' comment by sharing their own engineering endeavours