The Copernicus Sentinel-2A satellite takes us over southern India to the capital of Telangana: Hyderabad.
Home to almost seven million people and covering about 650 sq km, Hyderabad is one of the largest metropolitan areas in India. It lies on the banks of the Musi River, which can be seen running across the middle of the image. Although steeped in history, this rapidly growing metropolis has become a hub of commerce and an international centre for information technology, earning it the nickname of Cyberabad.
Captured on 14 May 2017, the image has been processed to highlight the different features in and around the city. The yellow and browns show the built-up centre while the light greens in the surroundings show arid fields. The shades of darker green depict vegetation and areas covered by trees. Interestingly, the bright blue, which appears, for example, along the Musi River and near other water bodies, is also vegetation such as parkland and grass.
While several lakes can be seen in the image, they are gradually being lost. It has been said that the city once had 7000 lakes, but there are now only about 70 and they are being subjected to pollution as the city expands and develops. Even the city’s most famous lake, the heart-shaped Hussain Sagar, is blighted with pollution from agricultural and industrial waste and municipal sewage.
The two identical Copernicus Sentinel-2 satellites carry high-resolution cameras working in 13 spectral bands. Images from the mission can be used to monitor pollution in lakes, changes in vegetation and urban growth.
This image is featured on the Earth from Space video programme.
This NASA/ESA Hubble Space Telescope image shows a massive galaxy cluster glowing brightly in the darkness. Despite its beauty, this cluster bears the distinctly unpoetic name of PLCK_G308.3-20.2.
Galaxy clusters can contain thousands of galaxies all held together by the glue of gravity. At one point in time they were believed to be the largest structures in the Universe — until they were usurped in the 1980s by the discovery of superclusters, which typically contain dozens of galaxy clusters and groups and span hundreds of millions of light-years. However, clusters do have one thing to cling on to; superclusters are not held together by gravity, so galaxy clusters still retain the title of the biggest structures in the Universe bound by gravity.
One of the most interesting features of galaxy clusters is the stuff that permeates the space between the constituent galaxies: the intracluster medium (ICM). High temperatures are created in these spaces by smaller structures forming within the cluster. This results in the ICM being made up of plasma — ordinary matter in a superheated state. Most luminous matter in the cluster resides in the ICM, which is very luminous X-rays. However, the majority of the mass in a galaxy cluster exists in the form of non-luminous dark matter. Unlike plasma, dark matter is not made from ordinary matter such as protons, neutrons and electrons. It is a hypothesised substance thought to make up 80 % of the Universe’s mass, yet it has never been directly observed.
This image was taken by Hubble’s Advanced Camera for Surveys and Wide-Field Camera 3 as part of an observing programme called RELICS (Reionization Lensing Cluster Survey). RELICS imaged 41 massive galaxy clusters with the aim of finding the brightest distant galaxies for the forthcoming NASA/ESA/CSA James Webb Space Telescope(JWST) to study.
The fuelling team suited and booted and ready to load the Copernicus Sentinel-3B satellite.
Getting a satellite ready to be launched involves a long list of jobs, but with the Sentinel-3B satellite now fuelled, this particular ‘to do’ list is significantly shorter. And, importantly, all is on track for liftoff on 25 April.
The team of propulsion experts spent two days carrying out the tricky task of fuelling the satellite with 130 kg of hydrazine and pressurising the tank.
Since hydrazine is extremely toxic, only specialists remained in the cleanroom for the duration. A doctor and security staff waited nearby with an ambulance and fire engine ready to respond to any problems.
This image of Expedition 56/57 crewmembers ESA astronaut Alexander Gerst and NASA astronaut Serena Auñón-Chancellor might pose a question or two. The short answer: the two astronauts are training at NASA’s Johnson Space Center in Houston, USA ahead of their launch to the International Space Station. Read on for the long answer.
Along with cosmonaut Sergei Prokopyev, Alexander and Serena will be launched to the Space Station in June aboard a Soyuz spacecraft.
Alexander will spend some six months aboard for his Horizons mission, named for its goal of broadening our knowledge of Earth, low-Earth orbit and beyond.
Alexander has an exciting (and packed) schedule of science for Horizons. Over 50 European experiments are planned, targeting areas such as human ageing and medicine, climate, digitalisation and fundamental research.
Alexander will continue running experiments such as the airway inflammation study Airway Monitoring and the new time perception study aptly called Time.
In addition to furthering our understanding of life in space, these experiments will have beneficial returns for life on Earth.
Alexander will spend the second half of his mission as commander of the Space Station, the second European astronaut to hold this leadership role.
Tune in to Alexander’s final press conference on Tuesday, 17 April at the European Astronaut Centre in Cologne for more on Horizons. The media day promises lightning talks on the planned science as well as a conversation with Alexander on exploration and his role as Station commander. More details and livestream link are available here.
As for the long answer: in addition to being pilots, scientists and technicians, astronauts must also be custodians of the Space Station. There’s no plumber available in orbit, so if the toilet breaks down, they must be able to fix it. Here, Alexander and Serena are learning to do just that. For the curious, the yellow cone is the urine collector and the grey switch turns on the suction.
This image shows an oblique perspective view of Ismenia Patera, a crater located in the Arabia Terra region of Mars’ surface. It was taken on 1 January 2018 by the stereo channels of the High Resolution Stereo Camera on ESA’s Mars Express, and highlights the uneven terrain around and within the crater and the flow-marked deposits on the crater floor.
An alternative to conventional circuit boards, these ‘3D-molded interconnect devices’ add electrical connectivity to the surface of three-dimensional structures.
The aim is to combine mechanical, electronic and potentially optical functions in a single 3D part, allowing the creation of intricate, precisely aligned designs using fewer parts while delivering significant savings in space and weight compared to conventional electronic manufacturing.
“These prototype interconnect devices were produced using injection-moulded plastics incorporating electrical metallisation,” explains ESA’s Jussi Hokka. “In principle, however, other materials can also be used, allowing the incorporation of sensors or the integration of shielding or cooling systems.”
Our sister planet Venus is a dynamic and unusual place. Strong winds swirl around the planet, dragging thick layers of cloud with them as they go. These fierce winds move so speedily that they display ‘super-rotation’: Earth’s can move at up to a fifth of our planet’s rotation speed, but winds on Venus can travel up to 60 times faster than the planet.
Observations from ESA’s Venus Express, which orbited Venus from 2006 to 2014, and other international spacecraft have probed deeper into this wind and cloud in past years, and uncovered some peculiar behaviour.
The side of the planet facing away from the Sun is somewhat more mysterious than the other side, but what we do know shows it to be quite different, with never-before-seen cloud types, shapes and dynamics – some of which appear to be connected to features on the surface below.
Super-rotation appears to behave more chaotically on the night side than the day side, but climate modellers remain unsure why. Night-side clouds also create different patterns and shapes than those found elsewhere – large, wavy, patchy irregular and filament-like patterns – and are dominated by mysterious ‘stationary waves’. These waves rise up within the atmosphere, do not move with the planet’s rotation, and appear to be concentrated above steep and higher-altitude regions of the surface, suggesting that Venus’ topography may well affect what happens in the cloud layers way up above.
These three images from the visible and infrared camera on Venus Express show these cloud features in detail: stationary waves (left), dynamical instabilities (middle) and mysterious filaments (right).
The Rockot fairing that will house the Copernicus Sentinel-3B on its journey into orbit.
Week In Images
9-13 April 2018