Space Warps is back: Help Us Weigh Galaxies!

4 May 2018 by Aprajita Verma

The Space Warps team and Zooniverse are excited to have joined forces with Science Friday to launch our most recent hunt for rare and elusive gravitational lenses. This time we are hunting for gravitational lenses in about 300,000 images of galaxies selected from the Hyper Suprime-Cam imaging survey on the Japanese 8.2m Subaru Telescope, Mauna Kea. These images are super deep and have excellent spatial resolution, ideal for finding gravitational lenses.

Help us meet the "1 million classifications in 1 week" challenge, we're almost there at 960,000 classifications and counting! Visit to join in, and tip us over the 1 million mark.

Citizens have already found some very interesting candidates in the first batch of 77,000 candidates. As a taster we've highlighted one here and more will be announced this evening (4th May) on the Science Friday programme that I'll be speaking on.

'Subject 21035634' (real name and coordinates will be revealed in a scientific paper once the campaign is over), is a great example of a galaxy-scale lens, where a single galaxy acts as lens focussing the light of a more distant background galaxy lying behind it. The Space Warps crowd has ranked with a perfect score of 1 (meaning it's a lens candidate with the highest probability)!

This candidate gravitational lens stands out for its aesthetics, with a nice blue arc seen through an extended envelope of stars from the lens galaxy, as well as its distance: the lens is located between 6 and 7 billion light years away. Finding distant lenses is one of the main goals of this project, and we expect there to be dozens of lenses at an even higher distance than this one.

Can you help us reach our 1 million classifications in 1 week goal and help us find more lenses? Visit - every classification counts!

Subject 21035634 has been correctly identified as lens by the following users: HexBerry, aussiegoodstuff, JSChris, ChronoTrigger, Dolorous_Edd, Pixelstain, tkuhnle, mitch, 770120179, John_M_Cummins, graham_d, ElisabethB, Bajari,Agumo, c.petty, nilium, HappyAmethyst, paulamichelllle, Bepkoam, CRuthWilliams,  It was flagged first on Space Warps Talk by user @Dolorous_Edd. 

To find out more about gravitational lensing visit

Aprajita Verma, Anupreeta More, Alessandro Sonnenfeld & Phil Marshall.

Categories: galaxies | gravitational lenses | zooniverse | dark matter | citizen science