Top stories: Earth's darkest year, mistakes in oceanographic studies and young crater under the ice of Greenland | Science

Why 536 was "the worst year to be alive"

After analyzing volcanic glass particles in the ice of a Swiss glacier, a team of researchers explained why some medieval historians claimed that 536 was the worst year of their existence. Earlier this year, a cataclysmic volcano in Iceland spew ashes in the northern hemisphere, creating a fog that has plunged Europe, the Middle East and parts of Asia into the black – day and night – for 18 months. Summer temperatures dropped 1.5 ° C to 2.5 ° C, triggering the coldest decade of the past 2300 years.

High-profile ocean warming paper to get a correction

Scientists behind a major study on global warming that occurred this month acknowledge errors in their calculations and claim that their conclusions are not as certain as those reported for the first time. The research, published in Nature, said the oceans are heating up much faster than expected. After a blog post reported some discrepancies in the study, the authors stated that they would submit a correction to the review.

Massive crater under the ice of Greenland heralds climate change in human time

An international team of scientists this week announced the discovery of a 31 km wide impact crater hidden under the Greenland ice cap, left after the fall of an asteroid of 1.5 km wide on the Earth. One of the 25 largest craters on the planet, it is remarkably cool, suggesting a recent strike over the past few million years. The moment is yet to be debated, but some researchers in the discovery team believe that the asteroid struck a crucial moment: about 13,000 years ago, as the world was melting away from the last ice age.

Do intestinal bacteria make a second home in our brain?

At the Society of Neuroscience's annual meeting in San Diego, California, last week, neuroanatologist Rosalinda Roberts made a splash with a presentation of the results of her laboratory at the University of Alabama in Birmingham , in which a bacterium was localized in human brain cells harvested from cadavers. Roberts was careful to note that his team did not rule out the possibility of sample contamination, but the results are one of many preliminary indications that bacteria could directly affect brain processes.

Great, darkly strange galaxy found hidden on the other side of the Milky Way

Astronomers have discovered a dwarf galaxy, called Antlia 2, which is one third the size of the Milky Way itself, which is hidden on the other side of our galaxy. As big as Big Magellan Cloud, the galaxy's biggest companion, Antlia 2 has escaped detection so far because it is 10,000 times weaker. Such a strange beast challenges models of galaxy formation and dark matter, an invisible material for gathering galaxies.