What is the first creature that comes to mind when you look at the dark cloud in this image? Perhaps a dark kitten with a vivid white nose, front paws stretching towards the right of the frame and tail up towards the left? Or perhaps a fox, running with its mouth open and looking ahead, its vigilant eyes pointing to the right?
In fact, this animal-themed shape belongs to a dark nebula, a dense cloud of gas and dust in the constellation of Orion, the Hunter, with the cat’s nose (or fox’s eye) corresponding to the Orion Nebula Cluster, a star cluster near the famous Orion Nebula, M42. The image is based on data from the first release of ESA’s Gaia satellite, and shows the density of stars observed while scanning that region of the sky.
While this particular nebula is not visible to the naked eye, similar clouds can be seen against the bright background of the Milky Way from dark locations in the southern hemisphere. Finding shapes in these dark nebulas is part of the astronomical tradition of various cultures, from South America to Australia, that include ‘dark cloud constellations’ resembling a variety of creatures in their firmaments.
Launched in 2013, Gaia has been charting more than a billion stars to unprecedented accuracy. This information is extremely valuable to astronomers who are studying the distribution of stars across our Galaxy.
Even in the dark patches where fewer stars are observed, Gaia’s meticulous census provides important information to study the interstellar material that blocks starlight. It is in these dark clouds of gas and dust that new generations of stars come to life.
The first data release from Gaia, published in 2016, contained the position on the sky of more than a billion stars, as well as the distance and motions of about two million stars. Astronomers worldwide are now looking forward to the next data release, planned for 25 April, which will include the distance and motions for the full sample of stars, greatly extending the reach of the previous survey.
So far, Gaia data have been used to study only the most nearby regions of star formation, within several hundred light-years of us. With the new data, it will be possible to investigate in great detail regions that are much farther away, like the Orion star-forming complex, located some 1500 light-years from us, and to estimate the 3D distribution not only of stars but also of the dusty dark clouds where stars are born.
Acknowledgement: A. Moitinho / M. Barros / C. Barata, University of Lisbon, Portugal; H. Savietto, Fork Research, Portugal
Preparing the Copernicus Sentinel-3B satellite for its ride into orbit on 25 April 2018 from the Plesetsk Cosmodrome in Russia.
The Copernicus Sentinel-3A satellite takes us over southern Siberia and the world’s largest freshwater lake: Lake Baikal.
Imaged on 14 March 2017, this deep lake is covered by ice. The entire lake is typically covered between January and May and in some places the ice can be more than 2 m thick.
Holding around 23 000 cubic km of water, Lake Baikal is the largest freshwater lake by volume in the world. It contains about 20% of the world’s fresh surface water, which is more than all of the North American Great Lakes put together. Baikal water is extraordinarily clean, transparent and saturated with oxygen. The high transparency is thanks to numerous aquatic organisms purifying the water and making it similar to distilled water.
At 25 million years old, this remarkable lake is also the oldest in the world. It is known as the Galapagos of Russia because its age and isolation have produced rich and unusual water wildlife, which is of exceptional value to evolutionary science. Occasionally, new species are discovered and it has been estimated that we know of only 70–80% of all the species inhabiting the lake. For these reasons, in 1996 it was listed as a UNESCO World Heritage Site.The lake is surrounded by mountain-taiga landscapes, which are also protected to preserve their natural state.
This image is also featured on the Earth from Space video programme.
The latest Dragon cargo vehicle was launched to the International Space Station on 2 April, taking with it ESA’s Atmosphere-Space Interactions Monitor.
Mounted in Dragon’s cargo bay, this suite of instruments will search for high-altitude electrical discharges associated with stormy weather. It is the first time that such a set of sensitive cameras, light sensors and X- and gamma-ray detectors are flying together to study the inner anatomy of luminous phenomena in Earth’s upper atmosphere and the link with bursts of high-energy radiation. Read more about the monitor here.
Dragon will dock with the Space Station on 4 April, with installation of the monitor expected on 13 April on the outside of Europe’s Columbus laboratory. Once it has been switched on and thoroughly checked for about a month, then the fascinating observations can begin.
This image is packed full of galaxies! A keen eye can spot exquisite ellipticals and spectacular spirals, seen at various orientations: edge-on with the plane of the galaxy visible, face-on to show off magnificent spiral arms, and everything in between. The vast majority of these specks are galaxies, but to spot a foreground star from our own galaxy, you can look for a point of light with tell-tale diffraction spikes.
The most alluring subject sits at the centre of the frame. With the charming name of SDSSJ0146-0929, the glowing central bulge is a galaxy cluster — a monstrous collection of hundreds of galaxies all shackled together in the unyielding grip of gravity. The mass of this galaxy cluster is large enough to severely distort the spacetime around it, creating the odd, looping curves that almost encircle the cluster.
These graceful arcs are examples of a cosmic phenomenon known as an Einstein ring. The ring is created as the light from a distant objects, like galaxies, pass by an extremely large mass, like this galaxy cluster. In this image, the light from a background galaxy is diverted and distorted around the massive intervening cluster and forced to travel along many different light paths towards Earth, making it seem as though the galaxy is in several places at once.
ESA Director General Jan Wörner speaking during the event in the Netherlands on 3 April 2018 to mark 50 years of ESTEC, the European Space Research and Technology Centre, since its royal inauguration in 1968.
The Director General was joined by his predecessor Jean-Jacques Dordain – who spoke of his three decades of working at or with ESTEC. Jan Rijpstra, Mayor of ESTEC’s home town Noordwijk, Franco Ongaro, Head of ESTEC, and Mona Keijzer, Dutch State Secretary for Economic Affairs and Climate.
The event was introduced by ESA astronaut Andre Kuipers, who spoke of his first very time visiting ESTEC – joining hundreds of thousands of other spectators on 5 June 1983 to watch the Space Shuttle Enterprise aboard its Boeing 747 carrier fly over the site on its way back from the Paris Air Show.
To see more pictures from the event, click here, or take a look at pictures from ESTEC’s five decades of space engineering.
Artist’s impression of the BepiColombo spacecraft attached to the upper stage and payload launch adapter (left) following launch. In this view, the Mercury Transfer Module is at the left, on top of the launch adapter, the Mercury Planetary Orbiter is in the middle, and Mercury Magnetospheric Orbiter is inside the sunshield visible at far right. The solar wings of the spacecraft open at a later stage.
BepiColombo is a joint endeavour between ESA and the Japan Aerospace Exploration Agency, JAXA.
This image shows the huge galaxy cluster MACS J1149.5+223, whose light took over 5 billion years to reach us.
The huge mass of the cluster is bending the light from more distant objects. The light from these objects has been magnified and distorted due to gravitational lensing. The same effect is creating multiple images of the same distant objects.
Astronomers using the NASA/ESA Hubble Space Telescope have found the most distant star ever discovered. The hot blue star existed only 4.4 billion years after the Big Bang. This discovery provides new insight into the formation and evolution of stars in the early Universe, the constituents of galaxy clusters and also on the nature of dark matter.
Go to Hubble uses cosmic lens to discover most distant star ever observed [heic1525] to learn more.
On 5 April 2018, Ariane 5 flight VA242 lifted off from Europe’s Spaceport in French Guiana and delivered two telecom satellites, DSN-1/Superbird-8 and Hylas-4, into their planned orbits.
Week In Images
2-6 April 2018