Saturn’s greatest storm
Saturn’s storm are sights to behold. Unlike other planets in the Solar System, the ringed planet seems to store up huge amounts of energy over multiple Earth decades and then release it all at once in the form of a swirling and chaotic lightning storm.
Scientists are unsure why and how the planet behaves this way, but these massive storms occur roughly once every Saturnian year - or once every 30 Earth years - and are known as Great White Spots.
The Great White Spot pictured here, also named the Great Northern Storm, was the largest and most intense storm that the international Cassini mission ever observed on Saturn. It began in late 2010 and lasted for months, but affected the clouds, temperatures and composition of the atmosphere for more than three years.
This true-colour view from Cassini was taken on 25 February 2011, roughly 12 weeks after the storm began, and shows the turbulent patterns within the storm. There appear to be two bands of storm, one further north and brighter than the other. In fact, the storm has thundered its way around the planet and caught up with itself. Some of the cloud south and west of the storm head can be seen tinged blue as it interacts with other currents in the atmosphere, while the storm head swirls with white and yellow as it heads westward to overtake its subtler tail.
It was a lucky coincidence that Cassini happened to be orbiting Saturn during the storm, offering an unprecedented opportunity to study the gas giant’s turbulent weather and climate patterns. Recently, Cassini found this storm to have been so immense and powerful that it was able to disturb the atmosphere at the planet’s equator some tens of thousands of kilometres away.
This disruption of the long-term, cyclical, continuing atmospheric patterns at mid-latitudes (dubbed informally by some as the planet’s ’heartbeat’), is thought to be due ’teleconnection’, which we also observe on Earth - when distant events within a climate system are somehow connected and can influence one another significantly.
This image combines red, green and blue filtered images from Cassini’s wide-angle camera to create a real-colour view. These images were taken at a distance of 2.2 million km from Saturn looking towards the sunlit side of the rings from just above the ring plane, and have a scale of 129 km per pixel.
The Cassini mission is a cooperative project of NASA, ESA and Italy’s ASI space agency. After 13 years of pioneering observations, Cassini ended its mission in spectacular fashion on 15 September 2017, plunging through the planet’s inner rings and atmosphere and breaking contact forever.
Galaxy full of cosmic lighthouses
This enchanting spiral galaxy can be found in the constellation of Ursa Major (the Great Bear). Star-studded NGC 3972 lies about 65 million light-years away from the Earth, meaning that the light that we see now left it 65 million years ago, just when the dinosaurs became extinct.
NGC 3972 has had its fair share of dramatic events. In 2011 astronomers observed the explosion of a type Ia supernova in the galaxy (not visible in this image). These dazzling objects all peak at the same brightness, and are brilliant enough to be seen over large distances. NGC 3972 also contains many pulsating stars called Cepheid variables. These stars change their brightness at a rate matched closely to their intrinsic luminosity, making them ideal cosmic lighthouses for measuring accurate distances to relatively nearby galaxies.
Astronomers search for Cepheid variables in nearby galaxies which also contain a type Ia supernova so they can compare the true brightness of both types of stars. That brightness information is used to calibrate the luminosity of Type Ia supernovae in far-flung galaxies so that astronomers can calculate the galaxies’ distances from Earth. Once astronomers know accurate distances to galaxies near and far, they can determine and refine the expansion rate of the Universe.
This image was taken in 2015 with Hubble’s Wide Field Camera 3, as part of a project to improve the precision of the Hubble constant - a figure that describes the expansion rate of the Universe.
Expedition 56/57 crew members training
Expedition 56/57 crew member Alexander Gerst during EMU suit-up at the Neutral Buoyancy Laboratory (NBL) at NASA’s Johnson Space Center.
X marks the Vehicle
It’s a bird. It’s a plane. It’s Jules Verne!
ESA’s very first Automated Transfer Vehicle is seen approaching the International Space Station against the glow of Earth’s horizon.
Launched 10 years ago on 9 March 2008, the maiden cargo ferry was named after the 19th-century French author and visionary, Jules Verne, who fascinated millions of young people and inspired space scientists and explorers with his extraordinary stories.
While it didn’t take the spacecraft 80 days to go around the world and reach the Space Station, it was nevertheless an extraordinary voyage.
Its task was to demonstrate that ATV could accomplish cargo flights to the International Space Station safely and reliably, and that all the advanced technologies work as planned. As the pioneer, its mission was deliberately more demanding than the flights of its successors.
Launched on an Ariane 5 rocket, ATV-1 spent 30 days in orbit before docking to the Space Station. During that time, it proved itself by navigating to the Station, and practising avoidance manoeuvres and proximity control. All the while it was being closely monitored by ATV Control Centre at the CNES French space agency site in Toulouse, France.
Jules Verne docked to the Space Station on 3 April and delivered equipment and spare parts, as well as food, air and water for the crew. Like all ATVs, it remained attached for about six months before undocking for a controlled destructive reentry into Earth’s atmosphere.
Four more ATVs carried 6.6 tonnes of cargo about every 17 months to the orbital outpost.
In addition to cargo delivery, ATV regularly boosted the Station into a higher orbit to overcome the effects of the faint drag of Earth’s upper atmosphere - the Station loses up to several hundred metres in altitude every day. To perform these manoeuvres, ATV carried up to 4 tonnes of propellant.
The five successful ATV missions proved the sophistication of this European spacecraft and, like the Columbus module, demonstrated European capability and excellence in space exploration.
The programme laid the foundation for ESA’s participation in the Orion programme that will take Europe, in collaboration with international partner NASA, beyond low Earth orbit.
ESA is developing the European Service Module that will power the Orion spacecraft to carry humans back to the Moon and beyond.
Crash in progress
Arp 256 is a stunning system of two spiral galaxies, about 350 million light-years away, in an early stage of merging. The image, taken with the NASA/ESA Hubble Space Telescope, displays two galaxies with strongly distorted shapes and an astonishing number of blue knots of star formation that look like exploding fireworks. The star formation was triggered by the close interaction between the two galaxies.
This image was taken by Hubble’s Advanced Camera for Surveys (ACS) and the Wide Field Camera 3 (WFC3). It is a new version of an image already released in 2008 that was part a large collection of 59 images of merging galaxies taken for Hubble’s 18th anniversary.
Wall of the Maxwell Test Chamber
The photographer who took this enigmatic picture inside ESA’s Maxwell Test Chamber - used for assessing the electromagnetic compatibility of entire satellites - has been shortlisted by the Sony World Photography Awards for architecture and still-life photography.
Once the chamber’s main door is sealed, Maxwell’s 9 m-high metal walls form a ’Faraday Cage’, blocking electromagnetic signals from outside. The ’anechoic’ foam pyramids covering its interior absorb internal signals - as well as sound - to prevent any reflection, mimicking the infinite void of space. Then a satellite can be switched on to detect any harmful interference as its various elements operate together.
Portuguese-born Edgar Martins collaborated closely with ESA to produce a comprehensive photographic survey of the Agency’s various facilities around the globe, together with those of its international partners.
The striking results were collected in a book and exhibition, The Rehearsal of Space and The Poetic Impossibility to Manage the Infinite .
Characteristically empty of people, Martin’s long exposures on wide film possess a stark, reverent style. They document the variety of specialised installations and equipment needed to prepare missions for space, or to recreate orbital conditions for testing down on Earth.
Made for Mercury
On 6 March 2018, the BepiColombo engineering model was delivered to ESA’s mission control centre in Darmstadt, Germany.
BepiColombo - ESA’s first mission to Mercury - is based on two spacecraft: the ESA-led Mercury Planetary Orbiter, with 11 experiments and instruments, and the Japanese space agency-led Mercury Magnetospheric Orbiter, carrying five experiments and instruments.
The engineering model delivered to Darmstadt comprises a 3D mock-up of the ESA module, plus a ’flat-sat’ mock-up of the transfer module, which ties the ESA and Japanese modules together during their cruise to Mercury.
In this photo, Airbus technician Stanislaw Ballardt looks out from inside the ESA module during installation work on 7 March.
The engineering model is an electrically faithful replication of the most critical elements of the spacecraft’s main platform and flight control systems, such as its computers, mass memory and power systems.
Flight controllers will use the model throughout the mission to check software and procedures before uploading them to the real spacecraft. They will also train for flight events such as firing the electric thrusters, swinging by planets and separating the modules.