It was an eclipse for the ages. This past week, many an eclipse chaser and the ‘eclipse curious’ made the journey to stand in the shadow of the Moon, for the only total solar eclipse of 2026. Viewers across northeastern Spain had thrilling views of a low to the horizon eclipse at sunset, while viewers to the north and across Iceland had dicier, cloudy skies to contend with. Here are amazing reader views of the eclipse, along with a few special ones from space.
The eROSITA telescope has released its second great catalogue of the X-ray sky with close to two million sources across half the sky, roughly double what it published before. Buried in it is a result from Bonn that matters more than the headline number. A team there went after the faintest part of a massive galaxy cluster, the outer region where fresh material is still arriving along threads of gas stretching between clusters. Nobody had measured that emission before. The gas turns out to be hotter, denser and poorer in heavy elements than the models say it should be.
Blazars are galaxies with a jet aimed almost directly at us, and they flicker across every part of the spectrum at once. Almost everything we think we know about them comes from short observing campaigns just a handful of days, every year or two, in one narrow band of energy. A Polish and German team has now done the opposite, following a single blazar for nearly twenty years with two orbiting observatories and in two observations from 2012 they found something in the spectrum that nobody had predicted.
Reading the atmosphere of another world means catching starlight as it filters through that planet's air during a transit. The signal is about one part in a million and a true Earth twin transits only once a year, so you cannot simply repeat the measurement until the noise averages away. Each attempt has to work on its own. A team led from Shanghai has proposed the alternative to building an impossibly large mirror in space - nine hundred, one metre telescopes, flying together, watching the same transit and analysing the light together.
A snowflake cannot form out of nothing. Water vapour will sit in the air quite happily, supercooled and reluctant, until it finds a speck of dust to build on and then it crystallises around it. Cosmochemists have had a version of that problem for decades. The early Solar System was a furnace of gas, and the first solid grains had to condense out of it somehow, yet condensing from a perfectly uniform gas is slow and difficult work. New research from Caltech, analysing fragments of a meteorite that fell over Mexico in 1969, suggests the seeds were already there. Buried inside the oldest solids we possess are specks of stardust from a star that lived and died before the Sun existed.
Ask what lies inside a black hole and the honest answer has always been a bit of a shrug and something about a singularity, a point where density becomes infinite and physics stops being able to tell you anything at all. It is the most unsatisfying answer in astrophysics, second only perhaps to what happened before the Big Bang. Now two theorists in China have produced a solution in which something else sits inside the horizon entirely, a neutron star, whole and intact, twelve kilometres across, its interior perfectly well behaved and apparently defying the laws of physics.
Astronomers were fortunate when the Einstein Probe detected the difficult-to-observe initial shock break out (SBO) from a supernova. The SBO is the first electromagnetic indication that a star is going to explode, and by observing it and the aftermath, researchers were able to determine what type of progenitor star exploded, and what it's pre-explosion environment was like.
