Arctic hunters. Herring is on the menu for these killer whales (Orcinus orca), photographed on 14 January, hunting the fish in a fjord near Tromsø, Norway. Norwegian authorities are considering strengthening protections for the mammals. Killer whales are being pushed farther north because warming waters are forcing the herring northward in search of spawning areas that are the right temperature (3°C).

Credits: ESA/Hubble & NASA, K. Stapelfeldt (CC BY 4.0)
A star is born. These blue, ethereal lights are known as Herbig–Haro objects, which form when jets of gas from a newborn star collide with existing gas and dust clouds. The Hubble telescope snapped this picture of five luminous Herbig–Haro objects in the NGC 1333 nebula, around 300 parsecs (1,000 light years) from Earth.

Credit: Berk Ozkan/Anadolu Agency/Getty
Free as a bird. A bird rescued from a bazaar in Istanbul, Turkey, where people trade the animals illegally. Staff from the Directorate General for Nature Conservation and National Parks recovered the bird, alongside others, and released them back into the wild.

Credit: Markus Scholz/dpa
Taking stock. Even aquariums have to do an annual inventory. A diver takes a green sea turtle’s (Chelonia mydas) yearly measurements at Sea Life Timmendorfer Strand in Germany. These measurements have shown that the turtle, Speedy, is growing at a rate of one centimetre per year.

Credit: Jim Funk/Cover Images
Cold snap. As cold air from the Arctic descended on the United States in January, much of the country experienced record-breaking low temperatures. Chicago was not spared from the polar vortex. This dramatic photo taken above the city shows Lake Michigan frozen over.

Credit: Mia Stålnacke/Cover Images
Pillars of light. Ice crystals in the atmosphere reflect streetlights and the moon, producing pillars of light that look like spotlights shining up into the sky. ‘Light hunter’ Mia Stålnacke captured this image in Kiruna, Sweden, against the eerie backdrop of the aurora borealis.

Credit: Jessica Hanley
Super blood wolf moon. On the night of 20 January, sky-gazers in the Americas and western Europe turned their cameras to the Moon to capture an unusual phenomenon: a super blood wolf moon. A lunar eclipse occurred as the Moon made its closest approach to Earth, causing it to appear red and larger than normal. The clouds parted just in time for Jessica Hanley to snap this shot in Los Angeles, California.

Credit: Jeff Milisen
See-through squid. This ghostly squid was captured by Jeff Milisen during a night dive in Hawaii, winning him first prize in the macro category of the Underwater Photography Guide’s ocean art competition 2018. Milisen spotted the 8-centimetre-long sharpear enope squid (Ancistrocheirus lesueurii) just under the surface of the water, following it as it dived 27 metres down through the dark ocean.

Credit: Mauro Pimentel/AFP/Getty
Dam disaster. A dam collapsed at an iron-ore mine near Brumadinho in southeastern Brazil on 25 January, leaving at least 121 people dead and more than 200 missing. This aerial photograph shows the destruction wrought by the disaster, which unleashed a torrent of liquid mining waste into the nearby countryside.

Credit: Ankita Patil/Peter Baas Lab., Drexel Univ.
Galaxy brain. These bright clusters of light look like distant stars, but they are, in fact, brain cells. Neuroscientist Ankita Patil snapped this image of neurons from the hippocampus, which were stained so that certain microscopic structures — actin and microtubules — glow under a fluorescent microscope. “This may be the most galaxy-looking picture of neurons I’ve taken,” Patil tweeted.

Credit: Reuters
Deadly tornado. Residents clear up debris after a tornado struck Havana on 27 January. Tornadoes are rare in Cuba, and this one was particularly destructive, killing six people, uprooting power lines and destroying homes and buildings.