An image of the desert in northern Mali taken by ESA astronaut Paolo Nespoli from on board the International Space Station.
Paolo’s third and last mission to the Space Station is named Vita, which means “life” in Italian, and reflects the experiments Paolo will run and the philosophical notion of living in outer space – one of the most inhospitable places for humans.
Connect with Paolo via: paolonespoli.esa.int
Southern Europe is in the grip of a relentless heatwave, fuelling wildfires and water shortages. Information from the Copernicus Sentinel-3A satellite has been used to map the sweltering heat across the region.
The map shows that on 7 August 2017, temperatures of the land surface rose above 40°C – not an usual occurrence over the last weeks. Much of Italy, including Rome, Naples, Florence, Sardinia and Sicily has been suffering these highs. With numerous towns and cities on the ministry of health’s maximum heat alert, the Italians have aptly dubbed the heatwave ‘Lucifer’. Extreme temperatures have also been recorded in Spain and Portugal, the Balkans and Greece.
As well as wildfires and water shortages, the heat has also led to some tourist attractions being closed, ill health and even some fatalities, and the drought is also threatening crops.
The map uses data from the satellite’s Sea and Land Surface Temperature Radiometer, which measures energy radiating from Earth’s surface in nine spectral bands – the map therefore represents temperature of the land surface, not air temperature which is normally used in forecasts. The white areas in the image are where cloud obscured readings of land temperature.
Blink and you might have missed them. But thanks to the cadence at which Rosetta took images of Comet 67P/Churyumov–Gerasimenko during its most active period in August 2015, scientists watching for brief but powerful outbursts caught plenty. Thirty-four no less, in the three months centred around the comet’s closest approach to the Sun, which occurred nearly two years ago, on 13 August 2015.
The increase in solar energy during these months warmed the comet’s frozen ices, turning them to gas, which subsequently poured out into space, dragging dust along with it. The violent, transient events occurred over and above regular jets and flows of material seen streaming from the comet’s nucleus, and were much brighter. Although typically only lasting a few minutes, some 60–260 tonnes of comet material could be released.
As can be seen from the montage shown here, some outbursts were long, narrow jets extending far from the comet nucleus, while others had a broader base that expanded more laterally. Others seem to be a hybrid of the two.
Scientists studying the outbursts even traced them back to their origins on the surface. Some were found to be linked to changes in local temperatures, perhaps in the early morning after many hours of darkness, or later in the day after several hours of heating, while others came from areas associated with pits or steep cliffs.
The images seen here are from both the high-resolution OSIRIS camera, and from the spacecraft’s navigation camera. Browse more images from Rosetta’s mission via ESA’s Archive Image Browser.
Rosetta arrived at the comet on 6 August 2014 and released its lander Philae on 12 November 2014. Rosetta followed the comet around the Sun for just over two years, watching the rise and fall of its activity over time and returning a wealth of scientific data from its suite of in situ and remote sensing instruments. It concluded its pioneering mission on 30 September 2016 by descending on to the comet’s surface in a controlled impact.
This humble parcel-sized hardware is Europe’s very first closed-loop life-support experiment to fly in space, 30 years ago this week.
Today, ESA leads the 11-nation Micro-Ecological Life Support System Alternative (MELiSSA) programme, seeking to perfect a self-sustaining life-support system that could in future be flown in space, supplying astronauts with all the oxygen, water and food they require.
“A long-term effort, MELiSSA formally began in April 1990 and continues to this day,” explains Christophe Lasseur, heading the programme. “But this flight experiment, developed with France’s CNES space agency and flown with China, was an important precursor.”
The experiment flew in space for five days on a recoverable ‘Fanhui Shei Weixing’ (FSW) recoverable capsule during 5–10 August 1987.
Two types of microorganism – algae dependent on oxygen and exhaling carbon dioxide, plus cyanobacteria dependent on carbon dioxide and exhaling oxygen – were placed in the glass vials, their mutually-dependent growth in weightlessness supported by nutrients and light, the latter supplied by a small light bulb.
The experiment had to be entirely self-reliant while the FSW capsule was in space, so power came from a set of off-the-shelf Duracell batteries.
The aim was to see how the algae grew in weightlessness, rather than being disturbed by the forces of reentry and landing. Accordingly, a shape-memory alloy released a fixative chemical after five days of flight. This stopped the cultures from growing any further, allowing accurate post-flight analysis of their behaviour in space.
“The nerve-racking part was waiting for the hardware to come back to us,” adds Christophe. “If it was lost, we would have had no results.”
Many further experiments have followed. Next month, the latest MELiSSA experiment is scheduled for the International Space Station, containing an advanced photo-bioreactor to see how algae growth rates are affected by microgravity and space radiation.
A small asteroid flying past Earth on 12 October will provide scientists with a valuable opportunity to learn more about its orbit and composition. The campaign will exercise the international network of observatories and research organisations working on planetary defence.
Astronomers recently spotted asteroid 2012 TC4 under a collaboration between ESA and the European Southern Observatory (ESO) to locate faint objects that might strike Earth. This is the first observation since 2012, when the asteroid was discovered by the Pan-STARRS observatory in Hawaii. It was found this time by ESO’s Very Large Telescope in Chile.
The original observations revealed the asteroid’s next approach to our vicinity would be in October 2017 but its orbit meant that it could not be tracked during the last five years, leaving astronomers unsure on how close it would come.
The new observations reveal it will miss Earth by 44 000 km. While it remains visible, astronomers will study the 15–30 m object in as much detail as possible, such as obtaining information on its composition.
An asteroid of this size entering our atmosphere would have a similar effect to the Chelyabinsk event. The 2012 TC4 Observing Campaign is part of a larger international initiative led by NASA. The campaign is an excellent opportunity to test the international ability to detect and track near-Earth objects and assess our ability to respond together to a real asteroid threat.
NASA’s powerful Space Launch System rocket is a few steps closer to launching the Orion spacecraft now that its liquid propellant tanks are ready for testing.
Assembled by the world’s largest robotic rocket welder at NASA’s Michoud facility in New Orleans, USA, the liquid oxygen tank seen here is ready for qualification, while the remaining three tanks are being processed.
The tanks must prove they can do exactly what they were designed to do as well as pass structural testing. At NASA’s Marshall Space Flight Center in Huntsville, Alabama, they will be strapped to the engines and fired to check their performance under launch conditions.
The liquid oxygen and hydrogen tanks hold over 2.6 million litres of propellant to power the rocket’s core stage that is comprised of four RS-25 engines and two solid rocket boosters.
Every bit of that thrust will be needed to propel the Orion spacecraft beyond low orbit to the Moon and beyond, for which ESA is contributing the European Service Module (ESM).
Once in orbit, the ESM will provide the spacecraft with electricity, water, oxygen and nitrogen as well as temperature control. A propulsion qualification module is being tested at the White Sands Test Facility in the US.
NASA’s uncrewed Exploration Mission-1 will be launched from the historic pad 39B at the Kennedy Space Center in Cape Canaveral, sending Orion some 70 000 km beyond the Moon before it returns to Earth.
Colour view of the Thaumasia mountain range and Coracis Fossae in the southern hemisphere of Mars.
This region was imaged on 9 April 2017 during Mars Express orbit 16807. The ground resolution is about 13 m/pixel and the images are centred on 281ºE/31ºS. North is right in this orientation.
The colour image was created using data from the nadir channel, the field of view which is aligned perpendicular to the surface of Mars, and the camera’s colour channels.
Greenland is usually associated with ice and snow, but the country has fallen victim to a large wildfire that has been raging since the end of July. The smoke billowing from the fire was imaged by the Copernicus Sentinel-2A satellite on 8 August 2017.
Greenland is almost entirely covered by a thick ice sheet, but there are exposed carbon-rich peatlands along the coast. The fire, which is in the western part of the country, appears to be a peatland fire. The fear is that the fire may have broken out because permafrost is melting, making the peat more susceptible to catching fire. Also, since it is peat, which can be used as a fuel, it could burn for some time.
The Sentinel-2 mission is based on a constellation of two identical satellites: Sentinel-2A and Sentinel-2B, each carrying a high-resolution multispectral camera working in 13 wavelength bands. The combination of high-resolution, novel spectral capabilities, a field of vision covering 290 km and frequent revisit times is providing unprecedented views of Earth. Information from this mission is helping to improve agricultural practices, monitor the world’s forests, detect pollution in lakes and coastal waters, and contribute to disaster mapping.
An animation of the fire that uses different combinations of these bands is also available. It shows the fire in natural colour (as here), highlights the flames and shows the burnt areas.
The subject of this NASA/ESA Hubble Space Telescope image is a dwarf galaxy named NGC 5949. Thanks to its proximity to Earth — it sits at a distance of around 44 million light-years from us, placing it within the Milky Way’s cosmic neighbourhood — NGC 5949 is a perfect target for astronomers to study dwarf galaxies.
With a mass of about a hundredth that of the Milky Way, NGC 5949 is a relatively bulky example of a dwarf galaxy. Its classification as a dwarf is due to its relatively small number of constituent stars, but the galaxy’s loosely-bound spiral arms also place it in the category of barred spirals. This structure is just visible in this image, which shows the galaxy as a bright yet ill-defined pinwheel. Despite its small proportions, NGC 5949’s proximity has meant that its light can be picked up by fairly small telescopes, something that facilitated its discovery by the astronomer William Herschel in 1801.
Astronomers have run into several cosmological quandaries when it comes to dwarf galaxies like NGC 5949. For example, the distribution of dark matter within dwarfs is quite puzzling (the “cuspy halo” problem), and our simulations of the Universe predict that there should be many more dwarf galaxies than we see around us (the “missing satellites” problem).
Cloudy Antarctic skies obscured a view of the first sunrise the team at Concordia Research station has seen in months. The base is located on a plateau 3200 m above sea level, at the very southern tip of Earth. The Sun does not rise above the horizon in the winter (May to August). The crew has been living without sunlight for the past four months and has experienced temperatures in the low –80°C.
This has meant a very structured life for Concordia residents, centred on social moments such as daily meals. Crewmembers can phone internationally and Internet is available but many start to feel disconnected from their contacts at home.
Once past the longest night in the world, things start to get brighter as the Sun rises near the horizon. The first sunrise is always a remarkable moment. From then on the winter crew start preparing for summer and the return of the summer scientists (November). The base is cleaned thoroughly, machinery is serviced, tents are erected and heated, and the runway is cleared of snow. Extensive work is required to welcome the new arrivals back to the base at the end of the world.
But the current crew will have to wait for the skies to clear to experience their sunrise. This image was captured by ESA's medical doctor in residence Carole Dangoisse.
Week in Images
7 - 11 August 2017