Three stories today. The Nobel Prize in Chemistry went to the two men who found how to build up one hand of a molecule over the other, Webb found traces of Mars-sized bodies smashing together around young stars, and the Earth's centre of mass has been measured shifting by a few millimetres with the seasons.
Chemistry
The 2026 Nobel Prize in Chemistry went to Henri Kagan and Kenso Soai, who opened the way to making far more of one mirror-image molecule than the other.
Molecules have left and right hands too. The parts and the joins are identical, yet the two are mirror images that cannot be laid on top of each other. Our bodies use only one of them: amino acids in the left-handed form, the twist of DNA always to the right. Run the reaction in a flask, though, and the two hands come out half and half.
Henri Kagan, in France, found how to tip a reaction towards one hand far harder than anyone thought possible, leaving a greater excess of it. Kenso Soai, in Japan, found a reaction in which the product helps its own making. If one hand is even slightly ahead, that hand makes more of itself, and a small lean grows like a snowball. In medicines only one hand may be the drug while the other can do harm, so the trick became an industry. It is also a clue to how life came to use one hand alone.
Through the eyes of the AtlasThe library piece on carbon bonding asks why carbon, with its four hands, became the stuff of life. Four hands let four different things be attached in different arrangements — and only then do left and right appear. This is the question after Pauling's: not just how atoms hold on to each other, but which way round.
A word of cautionWhy life settled on left-handed amino acids has not been explained. What this work shows is that a small lean can grow.
Source · NobelPrize.org
Space
Webb looked at the dust belts of twenty-one young stars and found a split: some had collisions violent enough to vaporise rock, others only grazing knocks.
After a star is born, dust and rubble are left around it, and those pieces collide and clump into planets. Around some young stars there is an unusual amount of dust, and it sits in close, where rocky planets form.
Researchers at the Space Science Institute in the United States and at an observatory in Hungary used Webb's mid-infrared eye on twenty-one such stars, reading from the colour of the light which minerals the dust is made of. In one group there was a great deal of silica, the stuff of glass, which forms only when rock has been melted and vaporised. The team reads that as a head-on smash between bodies the size of Mars. The other group was poor in silica, which fits gentler, grazing knocks between bodies about the size of our Moon. Every silica-rich disc belonged to a star younger than about 300 million years — so the big collisions come while planets are still being built.
Through the eyes of the AtlasOn 13 September this column carried a calculation that the Moon may have formed within five hours of a crash with a Mars-sized body. On the Cosmic Calendar that is the square where the Earth and the Moon appear. Today's story is a look at the same event happening now, around other stars.
A word of cautionNo collision was seen; it is inferred from what the leftover dust is made of. Twenty-one stars is a small number, and more are needed.
Source · ScienceDaily (NASA · Space Science Institute)
Earth
As snow, rain, seawater and air move about, the Earth's centre of mass is tugged along with them — and there is now a sharper way to measure how far.
The Earth's centre of mass is the balance point you would get by gathering all its mass into one spot. If the planet were simply rigid, that point would sit at the centre of its shape. But snow piles up, rain falls, and seawater and air move around, and the balance point is tugged along — by a few millimetres.
Researchers at NASA's Jet Propulsion Laboratory fire lasers from the ground at mirrored spheres put into orbit in the 1970s and 1990s and time what comes back. To that they added satellite navigation signals and the orbits of several other satellites, and they modelled how the ground itself bends under the weight of water and ice. Measured again this way, the yearly to-and-fro came out about half as large as the figure believed eight years ago. In March, northern snow pulls the point some 3 millimetres towards the North Pole; in April, rainwater in the Amazon pulls it about 2 millimetres towards South America.
Through the eyes of the Atlas"Measuring with the Same Ruler" is about who decides what a metre and a second are. When a satellite fixes your position, it too needs a point to measure from, and that point is the Earth's centre of mass. If the reference wobbles by millimetres, everything built on it wobbles too.
A word of cautionThis re-measures the seasonal to-and-fro, not the long drift caused by melting ice. Ground stations are spread unevenly between countries, so some error remains.
Source · ScienceDaily (NASA Jet Propulsion Laboratory)