Mount Etna’s spectacular smoke rings and more — April’s best science images

A long way down. For the first time, fledging emperor penguin chicks (Aptenodytes forsteri) have been filmed leaping into the ocean from the top of a 15-metre-high cliff at the edge of the Ekström ice shelf in Antarctica. Most penguins breed on sea ice that is much closer to the water, but in this case the roughly 700 chicks that were raised on the main ice shelf faced a precipitous drop on their first trip from the colony to the ocean. Filmmaker Bertie Gregory captured the moment for National Geographic.

Sandy sky. Clouds of dust from the Sahara Desert created an orange haze in Athens and other Greek cities. Authorities said it was the worst such event since 2018 and advised residents with respiratory conditions to wear masks, avoid exercise and limit time spent outdoors. The particles were carried by strong southerly winds, which also exacerbated dozens of wildfires in the region.

Three-ring circus. The sky over Italy’s Mount Etna fills with ‘smoke rings’ as a newly formed crater puffs out perfect circles of vapour. The circles — called volcanic vortex rings — form when cold air above the volcano causes hot gases travelling up the walls of a round vent to condense. Such displays are rare: the vent must have a circular shape and sides of the same height for such well-defined rings to form.

Jaw on the floor. A dentist spotted what is probably an ancient hominin jawbone embedded in a tile in his parents’ new travertine floor. Since posting about his find on Reddit, he has received offers of help from palaeontologists and a team of researchers is now planning to examine the mandible. This type of limestone often contains fossils, wrote palaeoanthropologist John Hawks in a blog post. “This naturally raises a broader question: How many other people have installed travertine with hominin fossils inside?”

Buried treasure. Archaeologists have unearthed a dining room decorated with well-preserved frescoes in the Roman city of Pompeii. The figures depicted include characters associated with the Trojan War such as Helen of Troy and her lover Paris, as well as figures from mythology. The room is thought to be part of a building that was buried in ash during the eruption of Mount Vesuvius in AD 79. Other excavations have revealed a courtyard containing roof tiles, work tools and building materials, which could offer insights into ancient building techniques.

Credit: Parco Archeologico di Pompei

Destructive downpour. Much of Dubai was left underwater after unprecedented storms in which around 25 centimetres of rain — around twice the yearly average rainfall for the United Arab Emirates — fell in a single day. Intense flooding led to the closure of roads, schools and offices and caused havoc at Dubai International Airport. Researchers say that the conditions that led to the deluge are exacerbated by climate change.