Cheer up with the newest Hubble Space Telescope image. Galaxy cluster SDSS J1038+4849 (c’mon NASA, get better names) appears to be grinning in the photo above.
The two orange ‘eyes’ are extremely bright galaxies. The smile lines? That’s gravitational lensing. Astronomers use massive galaxy clusters to help them see farther into the cosmos. Gravitational pull from these galaxy clusters is so strong they warp spacetime near them and act as a cosmic lense, magnifying the light behind them.
The ‘smile’ we see is called an Einstein Ring. This gravitational lensing only works when you have a perfect view of the galactic cluster and whatever it is you want to magnify behind it. In this case, the two galaxies make up the ‘eyes.’
You can check out all the Hubble Space Telescope images here. Gravitational lensing plays an integral role with the Hubble. Most images of incredibly distant galaxies use the technique. Here’s more than 100 images using gravitational lensing.
The illustration below shows how gravitational lensing works. The blue sphere is us. The yellow sphere is the massive galaxy cluster. See how it bends spacetime (the yellow grid)? The object on far right is the spiral galaxy that will be ‘magnified’ by gravitational lensing caused by the yellow sphere.