Space Smiley Face
A galaxy cluster appears to flash a smile at Earth in a newly released image from the NASA/ESA Hubble Space Telescope.
The eyes in this cosmic smiley face are actually very bright galaxies—technically known as SDSS J1038+4849—while the smile lines are arcs caused by an effect known as strong gravitational lensing. (See more galaxy pictures.)
When cosmic objects align with one right in front of the other, the foreground object's gravity can act as a lens, warping and magnifying the background object's light.
—Photo gallery by Mallory Benedict