Proba-1 view of Guam

A cloud-specked view of the US territory of Guam in the western Pacific Ocean, as seen by ESA’s Proba-1 microsatellite, which is still observing Earth despite being launched 16 years ago.

Antonio B. Won Pat International Airport is visible just right of centre. To the north is the town of Tamuning and the bluish, coral-rich shores of Tumon Bay, with the capital Hagåtña to the west.

The cubic-metre Proba-1 was the first in ESA’s series of satellites aimed at flight-testing new space technologies. It was launched on 22 October 2001 but is still going strong as the Agency’s longest-serving Earth-observing mission.

Proba-1’s main hyperspectral CHRIS imager acquires 13 square km scenes at 17 m spatial resolution across 18 programmable visible and near-infrared wavelengths. Proba-1 additionally carries a 5 m-resolution black and white camera. The microsatellite’s agile nature means it can image the same scene from a variety of viewing angles.

Onboard innovations include what were then novel gallium-arsenide solar cells, the use of startrackers for gyroless attitude control, one of the first lithium-ion batteries – now the longest such item operating in orbit – and one of ESA’s first ERC32 microprocessors to run Proba-1’s agile computer.

For more background on Proba-1, read this celebration in the ESA Bulletin.

Proba-1 led the way for the Sun-monitoring Proba-2 in 2009, the vegetation-tracking Proba-V in 2013 and the Proba-3 precise formation-flying mission planned for late 2020.

This image was acquired on 22 March 2018.

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Moon, Mars, Station

This image was taken by ESA astronaut Alexander Gerst from the International Space Station on 30 June 2018 when the Moon and Mars were at its closest so far during his six-month Horizons mission.

For illustration purposes, Mars has been highlighted and enlarged twenty times: the ‘Red Planet’ has a radius of 3389 km but at the time was roughly 67 million km from Earth while the Moon has a radius of 1737 km and was at a distance of around 411 000 km.

The distance from Mars to Earth varies as both planets orbit the Sun and it is at its closest in these weeks, appearing brighter than Jupiter in the night sky. The night of 27 July offers another periodic spectacle during the lunar eclipse when Earth casts its shadow over the Moon causing our satellite to appear red.

With careful planning and some luck it should be possible to see the Red Planet and the reddish moon with the International Space Station always flying past from West to East. In mainland Europe the Moon will rise eclipsed and the total eclipse will continue past 23:00 CEST.

The International Space Station, Moon and Mars are the destinations for ESA’s human and robotic exploration strategy, using low-Earth orbit for research and demonstrating technology, developing the Orion service module and elements for a gateway around the Moon and sending robotic probes to Mars, such as the ExoMars rover that will drill down 2 metres into the surface in search for life.

We would love to see any pictures taken showing the Moon, Mars and the International Space Station in one shot – even better if you manage to get all three during the lunar eclipse. Send your images to ESA’s social media channels, as a Facebook message to ESA, with hashtag #youresa on Instagram, or as a reply to the pinned tweet on @esaspaceflight. Provide as much background to how you took the picture as you can. The best three entries will be eligible to win exclusive prizes.  

Alexander took this picture with a 210 mm lens when not working on the dozens of European experiments run on the International Space Station. Flying at 28 800 km/h it only takes 90 minutes to circle Earth, meaning the astronauts on board fly through the night every 45 minutes: coupled with always-clear skies, there are more opportunities for an astronaut to take the perfect picture. 

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Looming iceberg

This satellite image, captured by Sentinel-2A on 9 July 2018, shows a huge iceberg perilously close to the village of Innaarsuit on the west coast of Greenland. If the berg breaks apart, waves resulting from the falling ice could wash away parts of the village.

The 169 residents of Innaarsuit are relatively used to seeing large icebergs floating by, but weighing around 10 million tonnes, this is reported to be the largest in memory. With chunks of ice calving from the iceberg, a number of residents were evacuated amid fears of a bigger break up. The local power plant is also on the coast so waves could also potentially shut down the village’s power supply. However, there are recent reports that strong winds from the south have started to push the berg to the north. The image also shows several other large icebergs in the vicinity.

The Copernicus Sentinel-2 mission is a two-satellite constellation. Each of the two satellites carries an innovative wide swath high-resolution multispectral imager with 13 spectral bands .The combination of high resolution, novel spectral capabilities, a swath width of 290 km and frequent revisit times provides unprecedented views of Earth and the ability to monitor rapidly changing events such as this.

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The legacy of Planck

Operating between 2009 and 2013, ESA’s Planck mission scanned the sky at microwave wavelengths to observe the cosmic microwave background, or CMB, which is the most ancient light emitted in the history of our Universe. Data from Planck have revealed an ‘almost perfect Universe’: the standard model description of a cosmos containing ordinary matter, cold dark matter and dark energy, populated by structures that had been seeded during an early phase of inflationary expansion, is largely correct, but a few details to puzzle over remain. In other words: the best of both worlds.

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Shaking Orion’s solar wings

Testing the solar wings of the European service module that will provide power, water, air and electricity to NASA’s Orion Moon module.

The solar arrays Orion will use to produce electricity are tested at ESA’s technical heart in the Netherlands. Folded for launch, the fragile solar panels need to survive the rumbling into space aboard the most powerful rocket ever built, NASA’s Space Launch System.

Orion’s solar panels will be folded inside the rocket fairing on the first leg of the trip around the Moon. Once released from the rocket they will unfold and rotate towards the Sun to start delivering power.

To make sure the solar panels will work after the intense launch, ESA engineers are putting them through rigorous tests that exceed what they will experience on launch day. This includes vibrating them on a shaking table and placing them in front of enormous speakers that recreate the harsh launch conditions.

Orion will eventually fly beyond the Moon with astronauts, the first time a spacecraft will support humans with European hardware will also be the farthest humans ever travel from Earth. The first mission – without astronauts – is getting ready for launch in 2019.

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Simulation of asteroid spin creating binary asteroids

This simulation  the top view on the left and side view on the right  shows an aggregate (assumed to be the common structure of small asteroids) asteroid that is spun-up due to differential heating, through the so-called 'YORP' effect. The orange particles are those initially at the surface and the white particles are those initially below the surface. While spinning up, the particles that are at mid-latitude move to the equator where the centrifugal force is greatest. When this force exceeds the gravity of the body, these particles escape and can potentially collide together to form a secondary. This mass shedding process turns an initially more or less spheroidal body into what is known as a top shape body, i.e. a spheroid with an equatorial bulge, which seems to be a common shape based on radar models of some small  asteroids, as well as direct images of asteroids Ryugu and Steins (and soon Bennu, the destination of NASA's OSIRIS-REx mission). Taken from Walsh, K.J., Richardson, D.C. & Michel, P. 2008. Rotational break up as the origin of binary asteroids. Nature 454, 188-191.

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A unique view of Mars Express

In this unique image, one spacecraft orbiting Mars records the presence of another. The narrow blur against a black backdrop is in fact ESA’s Mars Express spacecraft, taken by the Mars Orbiter Camera on NASA’s Mars Global Surveyor. It is the first-ever successful image of any spacecraft orbiting Mars taken by another spacecraft in a Martian orbit.

Mars Express, still in operation, represents ESA’s first visit to another planet in the Solar System. Launched in 2003 it marked the beginning of a new era for Europe’s planetary exploration, contributing over the past 15 years to the newly emerging picture of Mars as a once-habitable planet, with warmer and wetter epochs that may have once acted as oases for ancient Martian life. These findings have paved the way for missions dedicated to hunting for signs of life on the planet, such as ESA and Roscosmos’s two-mission ExoMars programme.

The Mars Global Surveyor was developed by NASA’s Jet Propulsion Laboratory and launched in 1996. It mapped the entire Martian planet from the ionosphere down through the atmosphere to its red, rocky surface.

On one special occastion, on 20 April 2005, from a distance of 250-370 km, the Mars Global Surveyor captured this remarkable shot of Mars Express, but unfortunately ESA’s satellite could not return the favour during the few years in which the two spacecraft operated simultaneously at the red planet.

On 2 November 2006 the NASA spacecraft failed to respond to messages and commands. Three days later a faint signal was detected, indicating the spacecraft had gone into safe mode and was awaiting further instruction. Attempts to re-contact the Mars Global Surveyor and resolve the problem failed, and the mission ended officially in January 2007.

Following this loss of contact, ESA’s Mars Express team was requested by NASA to perform actions in the hope of visually identifying the American spacecraft. Two attempts were made to find it, but both proved unsuccessful.

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First hot firing of P120C motor for Vega-C and Ariane 6

The hot firing of the development model of the P120C solid fuel rocket motor at Europe’s Spaceport in French Guiana on 16 July 2018, proves the design for use on Vega-C next year and on Ariane 6 from 2020.

The P120C is 13.5 m long and 3.4 m in diameter, and uses solid fuel in a case made of carbon composite material built in a single segment.

It will replace the current P80 as the first stage motor of Vega-C. Two or four P120Cs will be strapped onto Ariane 6 as boosters for liftoff.

This test was a collaboration between ESA, France’s CNES space agency, and Europropulsion under contract to Avio and ArianeGroup.

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Every point is a galaxy

At first glance this frame is flooded with salt-and-pepper static – but don’t adjust your set!

Rather than being tiny grains or pixels of TV noise, every single point of light in this image is actually a distant galaxy as observed by ESA’s Herschel Space Observatory. Each of these minute marks represents the ‘heat’ emanating from dust grains lying between the stars of each galaxy. This radiation has taken many billions of years to reach us, and in most cases was emitted well before the Solar System and the Earth had even formed.

This frame shows a map of the North Galactic Pole as imaged by Herschel’s Spectral and Photometric Imaging Receiver, SPIRE. As on Earth, astronomers define locations on a cosmic scale using a coordinate system. For the Milky Way galaxy, this coordinate system is spherical with the Sun at its centre, and provides values for longitude and latitude on the sky with respect to our Galaxy.

The North Galactic Pole lies far from the cluttered disc of the Milky Way, and offers a clean, clear view of the distant Universe beyond our home galaxy. In the sky, it is located somewhere in the northern constellation of Coma Berenices (Berenice’s Hair), a region that also contains an especially rich galaxy cluster known as the Coma Cluster. Serendipitously, the Coma Cluster is included in this map, adding over 1000 points of light to the tally of individual galaxies.

Herschel was active from 2009 to 2013, and used its instruments to study the sky in the far infrared. SPIRE was particularly well-suited to mapping large areas of sky, and observed the North Galactic Pole in three different filters simultaneously – such observations can be used to produce multicoloured images.

The image shown is a single-filter map obtained at a wavelength of 250 μm as part of the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS), and covers some 180.1 square degrees of sky. This used both SPIRE and another Herschel instrument, the Photodetector Array Camera and Spectrometer (PACS), to survey some 660 square degrees of sky in five wavelength bands and produce the largest far infrared surveys ever made of the sky lying outside our galaxy.

The North Galactic Pole imaged by PACS

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