And now, from the Department of Silver Linings, some good news about star death.

Every star dies, eventually. The details of how and when depend on the mass of the star. When lightweights like the Sun run out of nuclear fuel, their outer layers drift out and away like dandelion fluff. Bigger stars — those more than ten times as massive as the sun — have more finales. These stars go supernova, strewing their guts across the galaxy in explosive shockwaves, including elements that can only be made via inside stars or in supernova explosions. Read more.

Radiocarbon dating can still be considered a reliable method for determine the age of artefacts and materials, according to a new study.

Recently, it was suggested that the dates offered by radiocarbon dating are increasingly being distorted by external factors. Human carbon dioxide emissions have sped up the reduction of the carbon isotope C-14 in the Earth’s atmosphere, bringing into question the accuracy of the method’s results.

The author of a new study published in the journal Environmental Research Letters argues that the level of distortion caused by anthropogenic emissions can actually be precisely identified. He believes this can be done by measuring the carbon isotope C-13. Read more.

All life on Earth requires certain essential minerals, such are iron and zinc, to function properly. Animals obtain these minerals from their diet, but plants have to take them up directly from the environment and that can create problems. This is because although these minerals are generally abundant in the soil and water, they are mainly present in the form of ionic species that are not very soluble and so can’t easily be absorbed by plant roots.

One solution to this problem adopted by many plants, as well as by bacteria and fungi that obtain minerals directly from the soil, is to release compounds known as siderophores that can bind these ionic species. Because the resultant complexes are much more soluble, they can easily be taken up by plants, providing them with the necessary minerals. An interesting adjunct to this binding process is that it tends to work more effectively with certain isotopes than others, producing a natural isotopic fractionation of the metal ions in soil and water. Read more.

Isotopes - atoms of an element that are chemically identical but vary in neutron number and mass - are essential to nuclear medicine. In an effort to return to a stable mass, isotopes known as radioisotopes emit radiation that can damage diseased tissue and can be traced in certain environments, making them useful for medical imaging and cancer therapy, as well as tracking environmental change in oceans and soil, studying the fundamental science of nuclei and safeguarding national security. Read more.