Scientists still can’t agree on the universe’s expansion rate
A new study leaves the puzzle of the Hubble constant unresolved
![supernova](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2019/07/071619_ec_univexpansion_feat.jpg?fit=1030%2C580&ssl=1)
SUPERNOVA SURPRISE The universe’s expansion rate can be measured using stellar explosions called type 1a supernovas (one remnant of such an explosion shown). A new study deepens the quandary about why some supernova measurements disagree with estimates made using light from early in the universe’s history.
CXC/NASA, Univ. of Texas