ESA astronaut Tim Peake posted a series of photos of aurora as seen from on board the International Space Station, commenting: "Getting a photo masterclass from Scott Kelly – magical aurora."
More about the Principia mission: http://www.esa.int/principia
More photos from Tim on his flickr photostream: https://www.flickr.com/photos/timpeake
The interstellar medium fills the ‘empty’ space between the stars in our galaxy. It is a mix of molecular clouds, cold and warm gases, regions of electrically charged hydrogen, and more.
Molecular clouds are the densest part of the interstellar medium, holding most of its mass in the form of hydrogen gas. ESA’s Herschel space observatory has revealed that many are built around filaments, with dense threads snaking throughout each cloud. These filaments potentially transport material, and, when massive enough, are known to form new stars.
This Herschel image shows the Serpens Core, the heart of a giant molecular cloud. The Core is the bright clump towards the upper right, with a more diffuse secondary cluster, named Ser G3-G6, shown at the bottom right. Also visible as a faint yellow glow towards the upper left of the frame is a region known as LDN 583 that shines brightly in the far-infrared.
Giant molecular clouds contain up to 10 million times the mass of the Sun, and can stretch for hundreds of light-years. Compared to the rest of space they are dense, holding up to a thousand atoms per cubic centimetre – and even more in star-forming regions. However, these properties are relative: even at their densest, these clouds are more than 10 times emptier than the best laboratory vacuums we can produce on Earth.
These giant clouds are complex formations, most often made up of filaments mixed with clumpy and irregular folds, sheets and bubble-like structures. A typical spiral galaxy like the Milky Way can contain thousands of them, accompanied by many of their smaller relatives.
Serpens is an ideal target for scientists wanting to know more about giant molecular clouds, because it lies just 1400 light-years from us. Scientists compared Herschel’s observations of this cloud to a state-of-the-art simulation to find out more about the cloud’s properties, and to test the accuracy of their model.
They discovered a radial network of filaments stretching throughout the Serpens Core, filaments that are predicted to break and fragment to form the cores of new stars. These filaments resemble the spokes of a wheel, with the Core forming the hub.
This three-colour image is made from observations with Herschel’s PACS camera (blue and green) and SPIRE camera (red). The size of the region shown is 1.7x1.9º on the sky, where 1º corresponds to about 25 light-years.
This NASA/ESA Hubble Space Telescope image features the star cluster Trumpler 14.
One of the largest gatherings of hot, massive and bright stars in the Milky Way, this cluster houses some of the most luminous stars in our entire galaxy.
OSIRIS narrow-angle camera image taken on 17 January 2016, when Rosetta was 86.8 km from Comet 67P/Churyumov–Gerasimenko. The scale is 1.57 m/pixel.
More details via the OSIRIS Image of the Day website.
This beautiful, natural-colour image from Sentinel-2A on 18 September 2015 features the small nation of Bahrain and parts of eastern Saudi Arabia.
Located on the southwestern coast of the Persian Gulf, Bahrain is a small Arab state, made up of an archipelago consisting of Bahrain Island and some 30 smaller islands.
Owing to the high-resolution multispectral instrument on Sentinel-2A, the colour difference of the various types of surfaces is striking.
In the middle of the image, on the Persian Gulf, the King Fahd Causeway is clearly visible. Built between 1981 and 1986, it consists of a series of bridges and stretches of road connecting Saudi Arabia and Bahrain. The Saudi and Bahraini passport control centres are also noticeable in the middle of the Causeway.
On the right of the image is the island of Bahrain, home to some 1.5 million people, with its modern capital Manama featured at the top. The greys represent the densely built city centre and surrounding towns.
Strikingly relaxed and cosmopolitan, Manama has been at the centre of major trade routes since antiquity.
On the top right part of the island, on a smaller island about 7 km northeast of the capital, Bahrain International Airport is visible.
Most of Bahrain is a flat and arid desert plain, with recurrent droughts and dust storms the main natural dangers for its inhabitants. Famous for its pearl fisheries for centuries, today it is also known for its financial, commercial and communications sectors.
Towards the central left part of the island, Bahrain University is observable. Also visible, the Al Areen Wildlife Reservation, both a nature reserve and zoo, one of the five protected areas of the country, and the only protected area on land.
On the bottom-right tip of the island a series of horseshoe-shaped artificial atolls are clearly visible. Durrat Al Bahrain, one of the largest artificial islands in Bahrain, comprises six atolls and five fish-shaped islands.
On the left side of the image, in Saudi Arabia, part of the Rub’ al-Khali, the world’s largest sand desert, is also visible.
Distinct throughout the entire image, the striking variations of blue represent the shallow versus deep waters, with the presence of coral reefs.
Sentinel-2A has been in orbit since 23 June 2015 as a polar-orbiting, high-resolution satellite for land monitoring, providing imagery of vegetation, soil and water cover, inland waterways and coastal areas.
This image is also featured on the Earth from Space video programme.
ESA’s Proba-V minisatellite caught sight recently of this enormous smoke plume from a bushfire raging south of Perth in Western Australia.
This 300 m-resolution false-colour image, acquired on 7 January, shows smoke extending over Geographe Bay into the Indian Ocean. The smoke can be differentiated from the clouds also seen in the image by its blue–grey tint.
Bushfires are frequent events during the long, dry Australian summer. Certain native fauna, such as eucalyptus trees, have evolved to survive such bushfires, but the fires can cause substantial property damage and threaten lives. In this case, several hundred houses and an area exceeding 700 sq km had burnt down by 13 January.
Launched on 7 May 2013, Proba-V is a miniaturised ESA satellite tasked with a full-scale mission: to map land cover and vegetation growth across the entire planet every two days.
Its main camera’s continent-spanning 2250 km swath width collects light in the blue, red, near-infrared and mid-infrared wavebands at 300 m resolution and down to 100 m resolution in its central field of view.
VITO, the Flemish institute for technological research, processes and distributes Proba-V data to users. VITO has produced an online gallery highlighting some of the mission’s most striking images so far, including views of storms, fires and deforestation.
Next week sees a major symposium devoted to the minisatellite and its global output, taking place at Ghent in Belgium.
How do plants know which way is up? This might seem like an obvious question, but how exactly does a plant know which way to grow its roots and which way to grow towards the Sun?
Understanding the deeper mechanisms that cause a plant to grow in a particular direction has far-reaching possibilities for agriculture – as well as for astronauts who want to enjoy fresh vegetables on a long space mission.
This image shows a lentil seedling root that grew on the International Space Station before being preserved in resin and cut along its length for analysis.
The purple dots are starch-filled statoliths that usually drop towards gravity, but this plant grew in space and the statoliths are floating in the middle of their cells.
In addition to these cross-sections, almost 2500 pictures charted the 768 seeds growing over 31 hours in microgravity and hypergravity in the European Modular Cultivation System on ESA’s Columbus space laboratory.
“This research could not be done on Earth because gravity would get in the way of our readings,” explains Francois Bizet, who is analysing the images as part of a post-doctoral programme in France’s CNES space agency. Regular updates are posted on the experiment's blog.
The results from the Gravi-2 experiment are showing what could be responsible for sending growth-direction signals to the plant’s cells. Gravi-2 continued an earlier experiment that examined the limits of how plants perceive gravity, with this second experiment looking in particular at how calcium is used by plants to regulate growth.
On Earth, soluble calcium spreads to plant roots and is considered an important part of plant growth because they respond to environmental signals. Gravi-2 will also look at gene expression to highlight how intracellular calcium could be a second messenger for perceiving gravity.
“We need to grow the seeds in different environments to compare results and work out which change is due to gravity,” says Valérie Legué from the Université Blaise Pascal in Clermont-Ferrand, France.
“Understanding plant growth is the first step to adapting crops for more productive agriculture. If we could grow lentils vertically, for example, farmers could drastically increase crop yield per square metre.”
What might look like an abstract artwork is actually a novel antenna, small enough for a minisatellite, to track global ship traffic from orbit.
Commercial vessels are mandated to transmit Automatic Identification System (AIS) signals, which are used to track maritime traffic – the oceangoing equivalent of air traffic control. The system relies on VHF radio signals with a horizontal range of just 40 nautical miles (74 km), useful within coastal zones and on a ship-to-ship basis, but leaving open ocean traffic largely uncovered.
However, in 2010 ESA fitted an experimental antenna to Europe’s Columbus module of the International Space Station, demonstrating for the first time that AIS signals could also be detected from up in orbit, opening up the prospect of global ship tracking from space.
“Based on our testing, this new prototype designs offers a four-fold increase in ship detection performance,” explains ESA antenna specialist Nelson Fonseca, overseeing the project.
“The AIS detection system on Columbus employs a low-gain ‘whip’ antenna, receiving signals within a very broad beam, with corresponding potential for signal overlap and interference.
“This antenna design combines higher-gain with a more reduced footprint, allowing more of a focus on regions of highest interest, and can also discriminate between polarisations, increasing the likelihood of detection for any individual AIS signal within the antenna field of view.”
In addition, clever engineering has shrunk the overall antenna size to a size where up to five could be hosted on a single cubic-metre minisatellite.
“Despite its name, VHF is quite a low wavelength in space terms, implying a bulky antenna of about 1 m across and half-a-metre thick to operate ideally at that frequency,” Nelson adds.
“But the patterned square-shaped structure on the underlying face of our antenna changes the signal behaviour, enabling us to shrink the design to 50 cm width and 3 cm thickness – making it suitable for hosting on a smaller platform.”
The antenna was developed through ESA’s ARTES Advanced Research in Telecommunications Systems – Advanced Technology programme with Italian companies CGS as prime contractor and MVG as subcontractor in charge of the electrical design.
“CGS and MVG are highly interested in moving forward with the optimisation and environmental qualification of this outstanding antenna element,” explains Andrea Di Cintio, managing the project at CGS. “The next step will be to identify a specific mission and then optimise the design and qualification accordingly.”
“Significant reduction of antenna dimensions and weight without compromising electrical performance was challenging,” adds Andrea Giacomini, lead antenna designer at MVG. “It required a radical change in the design and validation approach. We are proud to have been involved.”
The first European hardware to arrive at NASA for Orion is the European Service Module structural test article. This test version of the service module has the same weight and configuration as the real thing and will undergo advanced testing at NASA’s Plum Brook Station in Ohio, USA.
In this picture the European Service Module structural test article is being ‘mated’ to the Crew Module Adapter, which connects the service module to the Orion Crew Module.
Once mating is complete the Service Module will weigh 13 000 kg in total. The Service Module will be placed on a shaker and vibrated to recreate the stress of launch.
Week In Images
18-22 January 2016