Science This Week | China’s rover finds signs of recent water on Mars, droughts likely ended the megacities of Indus Valley Civilisation Premium

Check out The Hindu’s science wrap featuring top 7 stories on new discoveries, findings, and studies in the scientific world from this week.

From finding West Eurasian genetic imprint in ancient DNA from Kerala’s Pattanam to increasing heat stress burden in Global South due to humidity, a lot has happened this week in the field of science. Find the most recent discoveries and findings here.

Expanding upon the historic first images of black holes, scientists have unveiled the first picture showing the violent events unfolding around one of these ravenous cosmic behemoths, including the launching point of a colossal jet of high-energy particles shooting outward into space. The new image of Messier 87 shows the entire system with the base of the jet of hot plasma, a fuzzy ring of light from hot plasma falling into the black hole, and a central dark area - sort of a donut hole - created by the black hole’s presence.

Water may be more widespread and recent on Mars than previously thought, based on observations of Martian sand dunes by China’s rover. The finding highlights new, potentially fertile areas in the warmer regions of Mars where conditions might be suitable for life to exist, though more study is needed. Zhurong rover observed salt-rich dunes with cracks and crusts, which researchers said likely were mixed with melting morning frost or snow as recently as a few hundred thousand years ago.

A critical antenna is jammed on a Jupiter-bound spacecraft launched two weeks ago. The 52-foot (16-meter) radar antenna on Juice unfolded only one-third of the way following liftoff. The radar antenna is needed to peer beneath the icy crust of three Jupiter moons suspected of harbouring underground oceans and possibly life, a major goal of the nearly $1.8 billion mission. Engineers suspect a tiny pin may be protruding. Flight controllers in Germany plan to fire the spacecraft’s engine in hopes of shaking the pin loose.

Researchers have found that heat stress burden, that comes with increasing temperatures, is not only dependent on local climate, but also on humidity, which can erase the cooling benefits that would come from trees and vegetation. As temperatures globally reach record-level highs and urban areas are facing increased heat stress, the Global South contends with an additional complicating factor - urban humid heat. In the humid Global South, the urban heat island is dominant over the urban dry island, resulting in two to six extra dangerous heat stress days per summer, the scientists said.

The archaeological site of Pattanam, on the South-western coast in Kerala’s Ernakulam district, is believed by historians to be part of the ancient port city of the Muziris that played a key role in trade and cultural exchanges between India and the Middle East, North Africa and the Mediterranean regions. Now, scientists have analysed DNA from the human skeletons to pinpoint the genetic ancestry of the people. They found the mitochondrial DNA of 12 ancient skeletal samples which shows the presence of both South Asian and West Eurasian-specific lineages.

By comparing the genetic blueprints of an array of animals, scientists are gaining new insights into our own species and all we share with other creatures. An international effort, called the Zoonomia project looked at 240 species of mammals, from bats to bison. They sequenced and compared their genomes — the instructions organisms need to develop and grow. They found that at least 10% of the human genome is largely unchanged across species through millions of years.