Black holes, shark skin and cockatoo tools — November’s best science images

JUICY tests. The Jupiter Icy Moons Explorer is a European Space Agency (ESA) mission scheduled to launch in 2022. Here, engineers at ESA in Noordwijk, the Netherlands, test a 1:18-scaled version of the spacecraft’s 16-metre-long radar antenna in a radio-interference-proof chamber. The instrument will probe down to nine kilometres under the surfaces of the Jovian moons Ganymede, Europa and Callisto to study the water oceans thought to be hidden beneath their ice crusts.

Round we go. Astronomers have made the most detailed observation yet of gas spiralling down a black hole — in this case, the supermassive black hole at the centre of the Milky Way. This video shows a computer simulation of what the orbiting gas (red) would look like from relatively nearby, together with simulated radio emissions (blue) from surrounding material. The actual gas cloud took about an hour to circle around, moving at 30% the speed of light.

Credit: Rory Cooper (Univ. Sheffield), Kyle Martin and Amin Garbout (NHM London)

Life algorithm. Shark skin is covered with denticles: tiny tooth-like spikes that help to reduce drag as the shark swims. A study of small-spotted catshark (Scyliorhinus canicula) has found that in the developing embryo, denticles distribute themselves in a ‘Turing-like pattern’, a process first proposed by British mathematician Alan Turing in 1952. The pattern is known to drive the development of feathers in birds, but this discovery hints at a common evolutionary origin much farther down the tree of life, up to 450 million years ago.

Credit: Goffin Lab, University of Veterinary Medicine Vienna

Parrot engineering. Among tool-wielding birds, Goffin’s cockatoos (Cacatua goffiniana) have an unusual skill, a zoologist has found. The parrots, which are native to Indonesia, can cut strips of cardboard to retrieve food through a hole, and even adjust the length of the strips if need be. But only one of six parrots in the study was also able to adjust the width of a tool that did not fit through the hole.

Credit: G.Porter-ESA

Moon factory. Materials engineers at an Austrian company have 3D-printed ceramic parts out of simulated regolith, the dust found on the lunar surface. Once printed, the pieces are hardened with light and baked in an oven. ESA is sponsoring research into this technique as a way of obtaining parts for building, or doing repairs on, a possible future Moon base without having to carry everything from Earth.

Credit: Cai, R. et al. Preprint at bioRxiv (2018).

Mouse-o-rama. The first technique to make an entire animal’s body transparent has been demonstrated on mice. Called vDISCO, it removes fat and pigment molecules from the dead mammal to make it transparent and stiff while preserving structures down to individual cells. Researchers also used ‘nanobodies’ — unusually small antibody molecules that come from llamas, camels and alpacas — to highlight specific organs or tissues.

Credit: Sakaguchi et al./eLife

Brain-o-rama. In a separate study, before making a mouse brain transparent, researchers tagged its neurons with individual colours. They did so by modifying the live mouse with genes for three separate fluorescent markers, each of which was expressed in different amounts in each neuron, leading to the variety of hues. This picture shows a sample from a mouse’s olfactory bulb — a region of the brain involved in smell.

Credit: NASA/JPL-Caltech

All clear. Soon after touching down on Mars on 26 November, NASA’s InSight lander sent back this image. It was taken using a camera mounted on the lander’s robotic arm — while the camera was still covered with a transparent safety lid. After deploying a sensitive seismometer and drilling five metres down under the surface, the mission will spend nearly two years studying the Martian geophysical environment.