Fluorescent mouse brain in coronal section.
Confocal microscopy was used to visualise a subgroup of neurones in the brain, engineered to express green fluorescent protein. Individual images were captured at 5.3 micrometers before being subsequently combined into the single image seen here. All neurones visualised are colour-coded by depth; from red (top) to orange, yellow, purple, blue and green (bottom).
Cosmic Optical Illusions in Ursa Major.
This image shows galaxies that appear as though they are in a galactic tug of war. In reality, the galaxy “above” is actually closer to Earth than the one “below”, and the two are not physically connected. Even more bizarrely, this image actually contains at least four galaxies, with the galaxy “above” actually comprising of three galaxies. Two are spiralling around one another in what seems to be the early stages of a merger, while a third sits separately towards the right of the image. This trio of galaxies are only 600 million light years away from Earth, in the constellation of Cepheus. The blue stream seemingly connecting the galaxies “above” and “below” is believed to have formed as a result of turbulent gravitational interactions from the merger of the two galaxies in the upper half of the image. As the two galaxies collide and merge, they throw off gas, dust, and millions of newborn stars. These young stars clump to form hot, massive, super-clusters and are responsible for the stark blue hue in this image.
Transmission electron microscope image of a T4 bacteriophage in the process of injecting its viral DNA into its host, an Escherichia coli bacterium.
This is an electron-micrograph image capturing the event of a bacteriophage landing on the surface of its host, an E.coli bacterium. Bacteriophages are viruses that infect bacterial cells. Most bacteriophages are 24-200 nanometers (nm) in size (that’s one-billionth of a metre!) but can be as small as 6.5nm. This image captures the phase at which a bacteriophage anchors to the cell before preparing to penetrate the membrane to inject its genetic load into the bacterial cell. From there, the virus will replicate within the bacterium before bursting out and invading other hosts. Bacteriophages are increasingly being used as alternatives to antibiotics to kill bacteria in humans. Bacteriophages have the advantage over antibiotics of potentially being much more specific to their target, sparing human cells and even human flora.
The Jellyfish Nebula: IC 443
This image captures the constellation of Gemini IC 443. It is approximately 5,000 light years from Earth. It is a galactic supernova remnant, a star that exploded between 3000-30,000 years ago and is one of the best-studied cases of a supernova remnant interacting with surrounding nebulous clouds. Near the apex of the nebula is a neutron star that is thought to have been the progenitor of the supernova explosion – the ultimate fate of a massive star. It is a process in which a star collapses in upon its own gravity, before exploding in an event that can momentarily outshine a galaxy, ejecting its matter at roughly 10% of the speed of light. The shape of this nebula earned it the nickname of the ‘Jellyfish Nebula’.
Skull of Homo Naledi, Discovered in a South African Cave in 2015
‘Homo Naledi’ is the name given to a series of bones found in a cave in South Africa, presumed to belong to the same species. ‘Presumed’ because, despite the media hype at apparently discovering a new ancestor of ours, there is very little that we know for sure about this creature. The date of the bones found in the cave are unknown, so we cannot place this species as our ancestor, as the bones may be dated to an age younger than our own. The bones are thought by some to belong to more than one species, as the skulls discovered seem to represent two distinct morphologies. Many of the features of this hominid are also entirely unique, making it difficult to know where to place it in the mosaic of evolution. Its tibia, femur, hands and feet all have unique features not found in other hominids. Indeed, its place within the genus of Homo is itself up for debate, with many of its features appearing to resemble the Australopith genus more. Given these issues, Homo Naledi has conjured more questions than answers…
PIA19966: Charon and Pluto: Strikingly Different Worlds
This is a composite enhanced image designed to bring Pluto (lower right) and Charon (upper left) together for the purpose of comparison. NASA’s New Horizons spacecraft snapped the images as it passed through Pluto’s orbit on July 14, 2015. The images have been processed identically so as to permit comparison of the different features. For example, note the similarity between Pluto’s red equatorial terrain and Charon’s dusky polar regions. The advantage of this image positioning is that it also gives an approximate idea of the relative sizes of these two planets. Pluto has had a chequered history, having been relegated from the category of planets in 2006 to its current status as a dwarf planet. It was relegated because it was not deemed to have met a third, new and essential criteria: a planet must “clear the neighbourhood around its orbit.” This meant that a planet had to have attained gravitational dominance in its immediate vicinity, having sucked up all other masses into itself. Pluto is surrounded by similarly sized planets such as Eris and Ceres and as such, could not be regarded as a planet, standing on its own two feet.