The ghostly green glow at the very top of this image reveals the presence of 46P Wirtanen – a relatively small comet with an estimated diameter of 1.2 kilometers. Had the path of history taken a different course, we would have much more than estimates about this Jupiter-family comet.
Completing one full orbit of the Sun every 5.4 years, 46P/Wirtanen was the original target of ESA’s Rosetta spacecraft. With the original launch window missed, the now famous comet 67P/Churyumov-Gerasimenko instead became the first ever visited by a human spacecraft and probe.
Five years ago this week, on 20 January 2014, Rosetta’s internal alarm clock woke up the spacecraft following a 31-month deep-space hibernation. In one of the most exciting moments for Rosetta scientists and mission operators on Earth, the spacecraft called back home confirming everything was working fine and that it had survived the most distant part of its journey.
The recent visit of 46P Wirtanen reminds us of the remarkable achievement that was the Rosetta mission, the dynamic nature of space exploration and the flexibility of mission teams who seamlessly moved from one green and remote Solar System comet to another, rubber duck shaped body.
This stunning photo was taken by photographer Ollie Taylor over the famous ‘Durdle Door’ rock arch on the Dorset Jurassic Coast, on the evening of 9 December 2018. Check out more of Ollie’s images on his website, www.ollietaylorphotography.com.
The Copernicus Sentinel-2 mission takes us over Gangotri, one of the largest glaciers in the Himalayas and one of the main sources of water for the Ganges River.
The Gangotri Glacier is in the Indian Himalayan state of Uttarakhand. The head of the glacier can be seen in the lower-right of the image near the Chaukhamba Peak. From here, Gangotri flows around 30 km northwest, but like many of the world’s glaciers it is in retreat. Studies suggest that Gangotri has been receding for well over 200 years. Measurements have shown, that it retreated by as much as 35 metres a year between the mid-1950s and mid-1970s. While this has now reduced to about 10 metres a year, observations show that the glacier is thinning.
The glacier’s terminus is called Gomukh, which means ‘mouth of a cow’, presumed to describe what the snout of this huge glacier once resembled. Importantly, the headwaters of the Bhagirathi River form here. In Hindu culture and mythology, this is considered to be the source of the Ganges and consequentially the destination for many spiritual pilgrimages and treks. Gomukh is a 20 km trek from the village of Gangotri, which is in the top left of the image. While Gomukh and Gangotri have much spiritual significance, the Bhagirathi River offers an important supply of freshwater as well as power as it passes through a number of power stations, including the Tehri hydroelectric complex 200 km downstream (not pictured).
Gangotri is in an area also known as ‘the third pole’, which encompasses the Himalaya-Hindu Kush mountain range and the Tibetan Plateau. The high-altitude ice fields in this region contain the largest reserve of freshwater outside the polar regions. With such a large portion of the world’s population dependent on water from these cold heights, changes in the size and flow of these glaciers can bring serious consequences for society by affecting the amount of water arriving downstream.
From the vantage point of space, satellites, such as the Copernicus Sentinels, provide essential information to monitor the changing face of Earth’s glaciers, which are typically in remote regions and therefore difficult to monitor systematically from the ground.
This image, which was captured on 7 January 2018, is also featured on the Earth from Space video programme.
he traditional start-of-year gathering, providing an overview of ESA’s achievements in 2018 and the challenges ahead in 2019, with a particular focus on Space19+, the ministerial conference to be held in Seville, Spain, in November 2019.
The remarks were concluded with an interactive question-and-answer session with the ESA Director General and Programme Directors.
Usually associated with video games, virtual reality is an immersive technology that simulates physical presence and interaction.
Today astronauts use computer simulations to help prepare for life on the International Space Station, practising spacewalks and operating equipment in microgravity – all while never leaving the ground.
ESA astronaut Luca Parmitano is hard at work preparing for his Beyond mission. In this image, Luca is navigating through a computer-generated environment to learn the route he might take outside the Space Station on a spacewalk, helping him to take decisions and act more quickly during the actual spacewalk. The training facility is part of Virtual Reality Laboratory at NASA’s Johnson Space Center in Houston, USA.
Luca is also getting reacquainted – Luca flew to the Space Station in 2013 – with safety procedures, robotic operations and learning about the experiments he will conduct in the orbital outpost.
He will be launched for his six-month stay aboard the International Space Station in July as part of Expedition 60/61, alongside NASA astronaut Andrew Morgan and Roscosmos cosmonaut Alexander Skvortsov.
International cooperation in human spaceflight does not only take place on the Space Station but begins well before, during training. Astronauts prepare not only at NASA’s Johnson Space Center but also at Star City near Moscow, and of course at the European Astronaut Centre in Cologne, Germany.
Luca will serve as Space Station commander during the second half of his mission. This will be the third time a European astronaut has held this leadership role, but the first time by an Italian astronaut.
How does Luca plan to take on this exciting yet challenging responsibility?
“I see myself as a facilitator. My goal will be to put everybody in the condition to perform to the best of their capability,” he says.
Testing a candidate design for a subsonic parachute to slow a future mission to Mars inside Canada’s National Research Council wind tunnel, in Ottawa.
Mars has a thin but substantial atmosphere, which is both a hindrance and a help to mission designers. Protective heat shields must be flown to protect any spacecraft making atmospheric entry but parachutes are then able to slow down and stabilise their descent.
Up until now single parachutes have been employed for Mars missions, but in future a double parachute system offers a way to deliver a greater payload to the surface with enhanced trajectory control. A smaller, supersonic parachute for initial deceleration would be supplemented by a larger subsonic parachute for the descent phase.
Testing made use of a drone, a helicopter and low- and high-altitude balloons as well as the 9 x 9 m Canadian wind tunnel pictured, plus a smaller 2 x 3 m wind tunnel at the same site – in combination with high-fidelity software simulations.
One test even seeded the air around a parachute with tiny droplets of olive oil, which were laser-scanned to better view their flow pattern.
“This was a very challenging project involving many tests at different facilities,” comments Luca Ferracina, overseeing the work for ESA.
“We collected an enormous amount of data to help us to better understand the behaviour and performance of many parachute types. This information will be key to designing future parachutes for Mars along with other planets such as Venus, Neptune and Uranus.”
The first assembled Spacebus Neo module is pictured at Thales Alenia Space Cannes, France.
Spacebus Neo is a new telecom satellite product line by Thales Alenia Space, developed under ESA’s Neosat programme.
The first satellite will be Eutelsat’s Konnect, which will provide broadband to Europe and Africa.
Saturn’s moon Titan is enveloped in a thick atmosphere, but through the infrared eyes of the international Cassini mission, the moon’s myriad surface features are revealed in this exquisite global mosaic.
Observing the surface of Saturn’s largest moon, Titan, in visible light is difficult due to the globe-enshrouding haze that envelops the moon. On 14 January 2005, the mystery as to what lay beneath the thick atmosphere was revealed as ESA’s Huygens probe – carried to Titan by Cassini – made the first successful landing on a world in the outer Solar System. During the two-and-a-half hour descent under parachute, features that looked remarkably like shore lines and river systems on Earth appeared from the haze. But rather than water, with surface temperatures of around –180ºC, the fluid involved here is methane, a simple organic compound that also contributes to the moon’s obscuring atmosphere.
Thanks to Cassini, which studied Saturn and its rings and moons for thirteen years, Titan was extensively mapped and analysed. One result is this stunning sequence of images created using data acquired by Cassini’s Visual and Infrared Mapping Spectrometer (VIMS), whose infrared observations peered through Titan’s atmosphere, complementing the views obtained by Huygens during descent and on the surface. The maps combine data from the multitude of different observations made under a wide variety of illumination and viewing conditions over the course of the mission, stitched together in a seamless mosaic to provide the best representation of Titan’s surface to date.
The colours reflect variations in materials on the moon’s surface. For example, the moon’s equatorial dune fields appear a consistent brown colour, while bluish and purple hues may indicate materials enriched in water ice.
The image was first published in July 2018 – read more here about how the image was created, and enjoy a video featuring further stunning visuals here. The complete Cassini VIMS data archive of Saturn’s satellites is available here.
The Cassini mission is a cooperative project of NASA, ESA and Italy’s ASI space agency. The mission concluded in September 2017.
A half-scale version of the ExoMars rover, called ExoMars Testing Rover (ExoTeR), seen manoeuvring itself carefully through the red rocks and sand of 9x9 m Planetary Utilisation Testbed, part of ESA’s Planetary Robotics Laboratory in its ESTEC technical centre in the Netherlands, as a test of autonomous navigation software destined for ESA’s ExoMars 2020 mission to the Red Planet.
This huge ball of stars — around 100 billion in total — is an elliptical galaxy located some 55 million light-years away from us. Known as Messier 89, this galaxy appears to be perfectly spherical; this is unusual for elliptical galaxies, which tend to be elongated ellipsoids. The apparently spherical nature of Messier 89 could, however, be a trick of perspective, and be caused by its orientation relative to the Earth.
Messier 89 is slightly smaller than the Milky Way, but has a few interesting features that stretch far out into the surrounding space. One structure of gas and dust extends up to 150 000 light-years out from the galaxy’s centre, which is known to house a supermassive black hole. Jets of heated particles reach out to 100 000 light-years from the galaxy, suggesting that Messier 89 may have once been far more active — perhaps an active quasar or radio galaxy — than it is now. It is also surrounded by an extensive system of shells and plumes, which may have been caused by past mergers with smaller galaxies — and implies that Messier 89 as we know it may have formed in the relatively recent past.
Messier 89 was discovered by astronomer Charles Messier in 1781, when Messier had been cataloguing astronomical objects for 23 years — ever since he mistook a faint object in the sky for Halley’s Comet. Upon closer inspection, he realised the object was actually the Crab Nebula. To prevent other astronomers from making the same error, he decided to catalogue all the bright, deep-sky objects that could potentially be mistaken for comets. His methodical observations of the night sky led to the first comprehensive catalogue of astronomical objects: the Messier catalogue! Messier 89 holds the record for being the last ever giant elliptical to be found by Messier, and the most perfectly spherical galaxy in the entire catalogue of 110 objects.
Week in images
14 - 18 January 2019