Mars Had Liquid Water On Its Surface. Here's Why Scientists Think It Vanished – A new study indicates that the relatively low mass of Mars allowed most of its water to be lost to space billions of years ago, rather than retained on its surface.

Source: Zhen Tian, et al. Potassium isotope composition of Mars reveals a mechanism of planetary volatile retention. Proceedings of the National Academy of Sciences, 2021.

A Cosmic Ray Event Pinpoints the Viking Landing in Canada – The celestial storm produced carbon-14 atoms found in the rings of a tree felled by Norse explorers, proving they made it to North America 1,000 years ago.

Source: Margot Kuitems, et al. Evidence for European presence in the Americas in ad 1021. Nature, 2021.

Disturbing Answers to the Mystery of Tuskless Female Elephants – Poaching brings evolutionary pressure for tusklessness

Source: Chris T. Darimont, Fanie Pelletier. Of war, tusks, and genes. Science, 2021.

Watch this wooden knife cut effortlessly through juicy, medium-well-done steak – Also: A hardened wood nail performed as well as its stainless steel counterpart.

Source: Bo Chen, et al. Hardened wood as a renewable alternative to steel and plastic. Matter, 2021.

Origins of domesticated horses traced to north Caucasus region, study finds – Horses were first domesticated in the northern Caucasus region, before conquering the rest of Europe and Asia within a few centuries, according to research published Wednesday by the journal Nature.

Source: Pablo Librado, et al. The origins and spread of domestic horses from the Western Eurasian steppes. Nature, 2021.

Haunting lemur songs have a rhythm similar to human music – Human music often has a natural rhythm to it, and the roots of that rhythm might stretch back to the ancestors we shared with indris, a type of lemur

Source: Chiara De Gregorio, et al. Categorical rhythms in a singing primate. Current Biology, 2021.

Martian floods? Scientists say rover found evidence – NASA's Perseverance rover discovered evidence that the Jezero crater on Mars it touched down in was once a lake bed fed by a river with floods, scientists say.

Source: Perseverance rover reveals an ancient delta-lake system and flood deposits at Jezero crater, Mars. Science, .

Morphable Materials Based on Neutrally Stable Units – Creating intelligent, shape-changing materials is a particular focus in the field of materials science currently. However, the technology is still fairly new.

Source: Gaurav Chaudhary, S. Ganga Prasath, Edward Soucy, L. Mahadevan. Totimorphic assemblies from neutrally stable units. Proceedings of the National Academy of Sciences, 2021.

A planet 6,000 light years from Earth reveals how the end of our solar system will look – A darkened planet circling the feeble remnant of a burned-out star about 6,000 light-years from Earth shows what our own solar system will look like at the end.

Source: J. W. Blackman, et al. A Jovian analogue orbiting a white dwarf star. Nature, 2021.

Gun violence rose 30 per cent in the US during the covid-19 pandemic – Gun violence rose overall in the US during the covid-19 pandemic. The highest increase was seen in Minnesota, while Alaska had a dip in gun violence cases

Source: Paddy Ssentongo, et al. Gun violence incidence during the COVID-19 pandemic is higher than before the pandemic in the United States. Scientific Reports, 2021.