Weak lensing

Weak lensing is a phenomenon where the gravitational pull of large structures like galaxy clusters slightly distorts the shape of distant galaxies. This bending of light, caused by gravity, doesn't produce dramatic arcs but subtly alters the appearance of many background galaxies. By analyzing these tiny distortions across the sky, scientists can map the distribution of dark matter and better understand the universe’s large-scale structure. It's akin to observing a faint, gentle stretching of images caused by unseen mass, providing valuable insights into cosmic composition and evolution.