Astronomers using the ALMA telescope discovered an unusual Einstein Cross with five images instead of the usual four. Initial confusion led to the hypothesis of a massive dark matter halo causing the extra image. Computer simulations confirmed that a dark matter halo, weighing trillions of times the sun's mass, was necessary to explain the observed gravitational lensing effect. This discovery provides a unique opportunity to study both a distant galaxy and the dark matter influencing its light.

Prepared by Olivia Bennett and reviewed by editorial team.