Astronomers have discovered two new galaxies without stars. Dark galaxies are so faint that their light can't be distinguished.
One galaxy, J0613+52, is 270 million light years away. It's swimming amid 2 billion solar masses of early hydrogen produced in the Big Bang. The galaxy isn't forming any stars, probably because the gas is too diffuse to clump together in clouds that become stars."We do not understand how a galaxy with such extreme characteristics can exist," Mireia Montes says.