Antarctica currently has exceptionally little ice—the lowest ever seen in June. On June 12th the continent’s sea ice covered just 10.7m square km. That is 1.15m square km below the previous minimum record for that date, from 2019, and 2.3m square km below the average for 1981-2010. The first difference represents an area a little larger than Colombia; the second an area the size of Mongolia—with three Britains tacked on. It is not yet clear why there has recently been such a precipitous drop in Antarctica’s sea ice, nor why it rose somewhat before that.
- Date Posted:
- June 29, 2023
Astronomers have found an extra-low hum rumbling through the universe. The discovery, announced today, shows that extra-large ripples in space-time are constantly squashing and changing the shape of space. These gravitational waves are cousins to the echoes from black hole collisions first picked up by the Laser Interferometer Gravitational-Wave Observatory (LIGO) experiment in 2015. But whereas LIGO’s waves might vibrate a few hundred times a second, it might take years or decades for a single one of these gravitational waves to pass by at the speed of light. The finding has opened a wholly new window on the universe, one that promises to reveal previously hidden phenomena such as the cosmic whirling of black holes that have the mass of billions of suns, or possibly even more exotic (and still hypothetical) celestial specters.