Orion Nebula, rise of the monkeys and over the cliff on a comet

Deeper into the Orion Nebula than ever before

An international team has made use of the HAWK-I infrared instrument on European Southern Observatory’s Very Large Telescope (VLT) to produce the deepest-ever view of the Orion nebula.

The famous nebula spans about 24 light-years within the constellation of Orion. It is visible from Earth with the naked eye as a fuzzy patch in Orion's sword. Its relative proximity makes it an ideal place to improve our understanding of how stars of different masses are formed.

This spectacular image has caused excitement because it reveals, unusually, a great abundance of very-low-mass objects – faint brown dwarfs and isolated planetary-mass objects.

These observations also tantalisingly hint that there may be many more planet-sized objects than previously thought. While we don’t have the technology to observe these objects easily yet, ESO's future European Extremely Large Telescope (E-ELT) will be able. It is scheduled to begin operations in 2024.

A peek inside a rocket tank

While this may look like a futuristic tunnel to another world, it is the inside of a nearly completed fuel tank for NASA’s powerful rocket – the Space Launch System.

The blue section in the image above is part of the world’s largest robotic welding tool. Inside, five barrels and one dome were welded to make the silver tank. Engineers will cap it with one more dome before it is completed. The finished product will be 8.3 metres in diameter and nearly 40 metres long, making it the largest major part of the SLS core stage that forms the rocket’s backbone.

While the tank is smooth on the outside, the interior is stiffened by ribs to make the walls light but strong. The tank will hold 203,2756 litres of chilled liquid hydrogen which will be completely combusted in the engines in the short 8.5 minutes it takes to send the SLS and Orion crew vehicle into orbit.

What teeth tell us about the rise of the monkeys

Palaeontologists at the University of California, Berkeley have identified distinctive features of primate teeth that allow them to track the evolution of our ape and monkey ancestors.

The finding sheds light on a mysterious increase in monkey species that took place about eight million years ago, during a period of climate change when the Earth began to warm, the Mediterranean Sea to dry up and Africa's thick forests to transition to savannah. The features were discovered after detailed study of the shapes of molars and premolars inherited by baboons in a long-studied colony at the Southwest National Primate Research Center in San Antonio, Texas.

Once it became clear that the relative lengths of the molars and premolars are an inherited trait much like eye colour, the researchers measured the teeth of other primates in museum collections around the world.

The data proved that the feature is inherited in a similar way in all primates – humans included. The discovery will also help track down the genes that control tooth development, assisting scientists intent on regrowing rather than replacing teeth.

Soaring over a comet’s cliffs

This striking view of 67P/Churyumov–Gerasimenko reveals portions of both comet’s lobes – often referred to as the “head” and the “body”, with dramatic shadows on the “neck” region.

Since rendezvousing with the comet on 6 August 2014, Rosetta has extensively mapped its surface. This image was taken from a distance of 25.8 kilometres and reveals an area about 2.3 kilometres across.

In the lower right of the image is the region Hathor, named after the ancient Egyptian deity of love, music and beauty. It is formed by a 900-metre cliff where the head declines steeply towards the neck and body of the comet.

In the upper right corner, smoother patches of the comet body are visible, covered in dust and boulders.

Rosetta will continue its close-up investigation of the comet until the grand finale, a controlled descent of the spacecraft to the surface of the comet on 30 September.

Record-breaking volcanic kettle on Iceland explored

The eruption of the Bardarbunga volcano in Iceland in 2014-2015 was the strongest in Europe for more than 240 years and the hole it left behind, the biggest caldera formation ever observed.

Calderas form when subterranean magma reservoirs collapse during volcanic eruptions, but as the occur so infrequently we still do not know that much about them.

So an international team leapt at the chance to document the Bardarbunga event. They observed it in unprecedented detail, using satellite images, seismological and geochemical data, GPS data and modelling in a hope to gain deeper insights into the mechanisms of caldera formation.

They found the process of subsidence was triggered by the lateral intrusion of magma from a reservoir 12 kilometres below the surface. It flowed for 45 kilometres along a subterranean path before erupting as a major lava flow northeast of the volcano. The subsidence was accompanied by 77 earthquakes of up to magnitude 5.

In their study published in Science this week, the scientists show how the ice-filled subsidence bowl developed gradually over the course of six months to become eight by 11 kilometres in area and up to 65 metres deep.