New ultra-precise measurements have confirmed the cosmos is expanding faster than models based on the early universe predict, while a separate study has dramatically shortened estimates of how long the universe itself will last.
Astronomers have long observed a mismatch in the universe’s expansion rate depending on how it is measured. Local observations of nearby galaxies point to a faster rate, while data from the early universe, such as the cosmic microwave background, suggest a slower pace. This longstanding puzzle is known as the Hubble tension.
A major international collaboration, the H0 Distance Network (H0DN), has now produced one of the most accurate local measurements yet. The team combined decades of independent distance measurements—including observations of red giant stars, Type Ia supernovae, and different galaxy types—into a unified “Local Distance Network.” Their result: the Hubble constant stands at 73.50 ± 0.81 kilometers per second per megaparsec, with precision just over 1 percent.
Hellbound and Down 