Cosmic time-delay twins could settle the universe’s expansion rate
Astronomers using the James Webb Space Telescope under the VENUS program have identified two gravitationally lensed supernovas, SN Ares and SN Athena. The foreground galaxy cluster MJ0308 splits their light into multiple images; the delayed images will reach Earth in the future—Ares in about 60 years and Athena within the next 1–2 years—providing a rare, self-consistent way to measure cosmic distances and constrain the Hubble constant, potentially helping resolve the ongoing disagreement over the universe’s expansion rate.
