A view looking north to south of Egypt’s famous Giza Pyramid Complex, as seen by ESA’s Proba-1 minisatellite.
The smaller Pyramid of Menkaure is seen to towards the centre of the image, with the larger Pyramid of Khafre down and left of it, with the Great Pyramid of Giza – the largest and oldest of the three – below and left of that.
Three smaller pyramids are adjacent to the Pyramid Menkaure. The Giza Plateau sits on the edge of Cairo, fringed by suburbs.
The cubic-metre Proba-1 is 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, having recently became the Agency’s longest-serving Earth-observing mission.
Proba-1’s main hyperspectral CHRIS imager is supplemented by this experimental High-Resolution Camera, acquiring black and white 5 m-resolution images.
Other 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.
This image was acquired on 6 January 2018.
In the next few days, an unoccupied Chinese space station, Tiangong-1, is expected to reenter the atmosphere following the end of its operational life. Most of the craft should burn up.
ESA is hosting a campaign to follow the reentry, conducted by the Inter Agency Space Debris Coordination Committee (IADC).
The 13 space agencies/organisations of IADC are using this event to conduct their annual reentry test campaign, during which participants will pool their predictions of the time window, as well as their respective tracking datasets obtained from radar and other sources. The aim is to cross-verify, cross-analyse and improve the prediction accuracy for all members.
These radar images (the image above is a composite of two separate images) were acquired last week by the Tracking and Imaging Radar system – one of the world’s most capable – operated by Germany’s Fraunhofer FHR research institute at Wachtberg, near Bonn, when the craft was at an altitude of about 270 km.
Data and images from the radar are being pooled as part of the IADC campaign.
The spacecraft is 12 m long with a diameter of 3.3 m and had a launch mass of 8506 kg. It has been unoccupied since 2013 and there has been no contact with it since 2016.
The craft is now at about 200 km altitude, down from 300 km in January, in an orbit that will most likely decay sometime between the morning of 31 March and the early morning of 2 April.
Owing to wide variations in atmospheric dynamics and the break-up process, among other factors, the date, time and geographic footprint of the reentry can only be forecast with large uncertainties.
In the history of spaceflight, no casualties from falling space debris have ever been confirmed.
Access a related animation created from radar data via YouTube.
NGC 1052-DF2 resides about 65 million light-years away in the NGC 1052 Group, which is dominated by a massive elliptical galaxy called NGC 1052.
This large, fuzzy-looking galaxy is so diffuse that astronomers can clearly see distant galaxies behind it. This ghostly galaxy is not well-formed. It does not look like a typical spiral galaxy, but it does not look like an elliptical galaxy either. Based on the colours of its globular clusters, the galaxy is about 10 billion years old. However, even the globular clusters are strange: they are twice as large as typical groups of stars.
All of these oddities pale in comparison to the weirdest aspect of this galaxy: NGC 1052-DF2 is missing most, if not all, of its dark matter. The galaxy contains only a tiny fraction of dark matter that astronomers would expect for a galaxy this size. But how it formed is a complete mystery.
Hubble took this image on 16 November 2017 using its Advanced Camera for Surveys.
When it comes to eggs, most of us are probably thinking of the chocolate variety that we hope will pass our way this weekend, but they’re difficult to spot from space. Instead, we can offer you this gorgeous Copernicus Sentinel-2B picture of Egg Island in the Bahamas.
Covering just 800 sq m, Egg Island is officially an islet. This tiny uninhabited patch is at the northwest end of the long thin chain of islands that form the Eleuthera archipelago, about 70 km from Nassau. Its name perhaps originates from the seabird eggs collected here.
The image, which Sentinel-2B captured on 2 February 2018, shows the sharp contrast between the beautiful shallow turquoise waters to the southwest and the deeper darker Atlantic waters to the northeast. Ripples of sand waves created by currents stand out in the shallow waters. These shallow waters are a natural nursery for sea turtles and other sea life. Any disturbance to this delicate ecosystem could spell disaster for wildlife. In fact, Egg Island was recently at risk of being developed as a cruise ship port, which would have meant dredging the seabed and destroying coral reefs. Fortunately, this plan didn't take hold because of the damage it would cause to the environment.
This image is also featured on the Earth from Space video programme.
ESA’s Atmosphere-Space Interactions Monitor (ASIM), the centre-bottom box in this image, is seen here after its installation in SpaceX Dragon’s open cargo carrier ahead of next week’s launch. On 2 April, a Falcon 9 rocket will deliver this instrument to the International Space Station to begin its mission of chasing down elusive electrical discharges in the atmosphere.
For years, their existence has been debated: elusive electrical discharges in the upper atmosphere were reported by pilots, but these ‘transient luminous events’, also known as red sprites, blue jets, and elves, are difficult to study because they occur above thunderstorms.
Satellites have probed them and observations have even been made from mountain tops but their viewing angle is not ideal for gathering data on large scales.
Then, in 2015, ESA astronaut Andreas Mogensen managed to record many kilometre-wide blue flashes around 18 km altitude, including a pulsating blue jet reaching 40 km from the International Space Station. A video recorded by Andreas as he flew over the Bay of Bengal at 28 800 km/h shows the electrical phenomena clearly – a first of its kind.
The Space Station’s low orbit proved again to be the vantage point from which a large part of Earth along the equator could be observed and these sprites and jets could be captured.
Researchers want to investigate the relationship between terrestrial gamma-ray bursts, lightning and high-altitude electric discharges across all seasons by tracking and collecting data continuously for at least two years.
Aside from being a little-understood phenomenon and part of our world, these powerful events can reach high above the stratosphere and have implications for how our atmosphere protects us from space radiation.
ASIM is an international project funded by ESA in close collaboration with NASA and is led by a team of scientists from the National Space Institute of the Danish Technical University (DTU Space).
After unpacking the Copernicus Sentinel-3B satellite at the Plesetsk launch site in Russia, the satellite was placed on the tilting dolly and put into a vertical position for testing. Over the following weeks, the satellite will be tested and prepared for liftoff, which is scheduled for 25 April 2018. Sentinel-3B will join its twin, Sentinel-3A, in orbit. The pairing of identical satellites provides the best coverage and data delivery for Europe’s Copernicus programme – the largest environmental monitoring programme in the world. The satellites carry the same suite of cutting-edge instruments to measure oceans, land, ice and atmosphere.
Sand and dust stirred up by desert storms in north Africa have caused snow in eastern Europe to turn orange, transforming mountainous regions into Mars-like landscapes.
This Copernicus Sentinel-2A image of Libya captured on 22 March shows Saharan dust being blown northwards across the Mediterranean Sea. Lifted into the atmosphere, the dust was carried by the wind and pulled back down to the surface in rain and snow. It reached as far afield as Greece, Romania, Bulgaria and Russia. While the orange-tinted snow baffled skiers, meteorologists say this phenomenon occurs about every five years.
The inauguration of the ‘Mirrored Painting’ by Italian artist Michelangelo Pistoletto, entitled 'Ritratto di Paolo Nespoli - Astronauta, Missione VITA', took place on 28 March 2018 at ESRIN, ESA’s centre for Earth observation in Frascati, Italy, as the climax of a joint initiative and a permanent symbol of the important link between space and art. The event hosted by the Head of ESA ESRIN and ESA's Director of Earth Observation Programmes Josef Aschbacher, was attended by ESA astronaut Paolo Nespoli, Michelangelo Pistoletto, ASI representative Fabrizio Zucchini and RAM radiartemobile representatives Dora Stiefelmeier and Mario Pieroni.
This original piece of art, created by famous artist Michelangelo Pistoletto who is known as one of the founding fathers of the Italian Arte Povera contemporary art movement, features a full-scale representation of ESA astronaut Paolo Nespoli. For Paolo’s VITA mission, ESA and ASI developed original ‘space and art’ initiatives as part of the communication activities to actively involve wider audiences. This began with Pistoletto’s development with ESA of the official patch for Paolo’s mission, which includes the artist’s symbol of his Third Paradise concept in the artwork.
A natural continuation of this cooperation was the ‘SPAC3’ app, which allowed users to select and combine Paolo’s images from space with their own photos. This activity was intended to draw attention to the wellbeing of our planet, and was inspired by the Sustainable Development Goals of the United Nations. These provided the basis for Paolo’s choice of photos, and the app users could respond with their own photos on the same theme.
As a social artwork project, SPAC3 demonstrated that the two worlds of art and science can work together with the common objective of highlighting issues affecting our planet, and showed how involving a wider public could contribute to the vision and become part of this collective work. This joint initiative was made possible via a partnership between ESA and RAM radioartemobile, in cooperation with ASI and Cittadellarte-Fondazione Pistoletto.
This image, captured by the Advanced Camera for Surveys (ACS) on the NASA/ESA Hubble Space Telescope, shows the spiral galaxy NGC 5714, about 130 million light-years away in the constellation of Boötes (the Herdsman). NGC 5714 is classified as a Sc spiral galaxy, but its spiral arms — the dominating feature of spiral galaxies — are almost impossible to see, as NGC 1787 presents itself at an almost perfectly edge-on angle.
Discovered by William Herschel in 1787, NGC 5714 was host to a fascinating and rare event in 2003. A faint supernova appeared about 8000 light-years below the central bulge of NGC 5714. Supernovae are the huge, violent explosions of dying stars, and the one that exploded in NGC 5714 — not visible in this much later image — was classified as a Type Ib/c supernova and named SN 2003dr. It was particularly interesting because its spectrum showed strong signatures of calcium.
Calcium-rich supernovae are rare and hence of great interest to astronomers. Astronomers still struggle to explain these particular explosions as their existence presents a challenge to both observation and theory. In particular, their appearance outside of galaxies, their lower luminosity compared to other supernovae, and their rapid evolution are still open questions for researchers.
The plane of the Milky Way is rich in star-forming regions, such as the one pictured in this stunning scene by ESA’s Herschel space observatory. To the far-infrared eye of Herschel, this region reveals an intricate network of gas filaments and dark bubbles interspersed by bright hotspots where new stars come to life.
The cooler regions, which emit light at longer wavelengths, are displayed in a red-brownish colour. Hotter areas, where star formation is more intense, shine in blue and white tones. Some areas are particularly bright, suggesting a number of luminous, massive stars are forming there.
Particularly striking is the chaotic web of gas filaments we see in this scene. Astronomers think there is a link between star formation and the filamentary structures in the interstellar medium. In the densest strands, the gas that makes up the filaments becomes unstable and forms clumps of material bound together by gravity. If dense enough, these collapsed blobs of gas eventually go on to become newborn stars.
Observations by Herschel showed the filamentary complexity to be ubiquitous in the plane of our Galaxy, from a few to hundreds of light-years. In nearby star-forming clouds, within 1500 light-years of the Sun, these filaments seem to be roughly all the same width – about a third of a light-year. This suggests a common physical mechanism in their origin, possibly linked to the turbulent nature of interstellar gas clouds.
The star-formation region in this image, centred around –70º longitude in galactic coordinates, is located in the Carina neighbourhood, home to the glorious Carina Nebula. Located some 7500 light-years away, Carina is one of the largest clouds of gas and dust in the plane of the Milky Way. It hosts the famous Eta Carinae, one of the most luminous and massive stellar systems in our galaxy.
Herschel, which operated from 2009 until 2013, was a large space telescope observing in the far-infrared and submillimetre parts of the spectrum. This spectral range is ideal to observe the glow from cool dust in the regions where stars form. As part of Hi-GAL, the Herschel infrared Galactic Plane Survey, the observatory surveyed the plane of our Galaxy, exploring the Milky Way’s star-formation regions in unprecedented detail. This image, a product of Hi-GAL, combines observations at three different wavelengths: 70 microns (blue), 160 microns (green) and 250 microns (red).
Week In Images
26-30 March 2018