A new study proposes an improved approach to determine lion densities and identify factors that affect their abundance, but there may be flaws say some.

In January 2006, NASA launched the New Horizons space probe to explore the horizons of the Solar System and know what’s beyond all the planets. The space probe sailed about 5.9 billion kilometres for almost a decade, with state-of-the-art instruments on board, before it met Pluto, a now downgraded ‘dwarf planet’. Three and a half years later and still gliding, it encountered ‘2014 MU69’—the farthest object in the Solar System ever to be visited by a spacecraft. Today, this oddly named object has a fancy moniker—Arrokoth—and we now know a whole lot about this distant Kuiper Belt Object than ever before, thanks to three new studies.

In the 18th and 19th century, Britain was abuzz with cranking steam engines, rattling power looms, and clattering machines. Amidst this daily ding, the world was witnessing a defining movement in human history—the Industrial Revolution—that soon spread to the rest of Western Europe. Powered by coal, the production of most things transitioned from hand to machine, spurring a rise in population and air pollution. For the next two centuries, London became infamous for its soot and smog, which turned fatal for about 12,000 people. Now, a new study has shown that this mal air has left its trace in the lofty Himalayan glaciers, thousands of kilometres away from Europe.

In a new study, an international team of researchers have found that large dams have heavily fragmented fish population across the world. Published in the Proceedings of the National Academy of Sciences, the study assessed about ten thousand species of fish worldwide affected by around 40,000 existing dams and 3,700 upcoming dams worldwide. The findings reveal that fish habitats are most disconnected in the United States, Europe, South Africa, India, and China. The proposed dams are poised to further worsen fish habitat connectivity in tropical watersheds like the Amazon, Congo, Mekong and Salween.