As if this Hubble Space Telescope picture isn't cluttered enough with myriad galaxies, nearby asteroids photobomb the image, their trails sometimes mimicking background astronomical phenomena.
The stunningly beautiful galaxy cluster Abell 370 contains an astounding assortment of several hundred galaxies tied together by the mutual pull of gravity. Located approximately four billion light years away in the constellation Cetus, the Sea Monster, this immense cluster is a rich mix of a variety of galaxy shapes.
Entangled among the galaxies are thin, white trails that look like curved or S-shaped streaks. These are trails from asteroids that reside, on average, only about 260 million kilometres from Earth – right around the corner in astronomical terms. The trails appear in multiple Hubble exposures that have been combined into one image. Of the 22 total asteroid sightings for this field, five are unique objects. These asteroids are so faint that they were not previously identified.
The asteroid trails look curved due to an observational effect called parallax. As Hubble orbits around Earth, an asteroid will appear to move along an arc with respect to the vastly more distant background stars and galaxies. The motion of Earth around the Sun, and the motion of the asteroids along their orbits, are other contributing factors to the apparent skewing of asteroid paths.
All the asteroids were found manually, the majority by “blinking” consecutive exposures to capture apparent asteroid motion. Astronomers found a unique asteroid for every 10 to 20 hours of exposure time.
These asteroid trails should not be confused with the mysterious-looking arcs of blue light that are actually distorted images of distant galaxies behind the cluster. Many of these far-flung galaxies are too faint for Hubble to see directly. Instead, in a dramatic example of “gravitational lensing,” the cluster functions as a natural telescope, warping space and affecting light traveling through the cluster toward Earth.
The field’s position on the sky is near the ecliptic, the plane of our Solar System. This is the zone in which most asteroids reside, which is why Hubble astronomers saw so many crossings. Hubble deep-sky observations taken along a line-of-sight near the plane of our Solar System commonly record asteroid trails.
Every year on 30 June, the global “Asteroid Day” event takes place to raise awareness about asteroids and what can be done to protect Earth from possible impact. The day falls on the anniversary of the Tunguska event that took place on 30 June 1908, the most harmful known asteroid related event in recent history. This year, ESA is co-hosting a live webcast with the European Southern Observatory packed with expert interviews, news on some of the most recent asteroid science results, and the truth about the dinosaurs. Watch 30 June at 13:00 CEST via www.esa.int/asteroidday.
For Asteroid Day, the Copernicus Sentinel-2A satellite takes us over the Gosses Bluff crater in the Northern Territory of Australia. The crater is visible in the left centre of the image and it is about 22 km in diameter. It was most likely formed 140 million years ago by the impact of a large comet or meteorite slamming into the surface of Earth.
This false-colour image shows an extremely dry area with some vegetation visible in reddish colours along the rivers and lakes. The intense colours of the image represent the mineral composition of the land surface, which is clearly visible owing to the lack of vegetation. Azurite is one of the minerals mined here.
A series of low hills and drainage structures can be seen in the lower part of the image, a result of erosion over the years. The West MacDonell Ranges can be seen in the upper section of the image and part of the Petermann Ranges are shown in the lower section.
The crater is around 200 km west of Alice Springs, famous for being the gateway to the Red Centre, Australia’s interior desert region.
Asteroid Day brings people from around the world together to learn about asteroids, the impact hazard they may pose, and what we can do to protect our planet, families, communities, and future generations from asteroid impacts. It takes place on 30 June each year, which is the anniversary of the largest asteroid impact in recent history, the 1908 Tunguska event in Siberia.
This year, ESA is co-hosting a live webcast with the European Southern Observatory packed with expert interviews, news on some of the most recent asteroid science results, and the truth about the dinosaurs. Watch 30 June at 13:00 CEST via www.esa.int/asteroidday.
This image, which was captured on 4 February 2016, is also featured on the Earth from Space video programme.
A ground penetrating radar antenna for ESA’s ExoMars 2020 rover being pre-cleaned in an ultra-cleanroom environment in preparation for its sterilisation process, in an effort to prevent terrestrial microbes coming along for the ride to the red planet.
Part of the Agency’s Life, Physical Sciences and Life Support Laboratory based in its Netherlands technical centre, This 35 sq. m ‘ISO Class 1’ cleanroom is one of the cleanest places in Europe. It is equipped with a dry heat steriliser used to reduce the microbial ‘bioburden’ on equipment destined for alien worlds.
The item seen here is the WISDOM (Water Ice Subsurface Deposit Observation on Mars) radar antenna flight model, designed to sound the subsurface of Mars for water ice.
“After pre-cleaning and then the taking of sample swabs, the antenna was placed into our dry heat steriliser, to target the required 99.9% bioburden reduction to meet ExoMars 2020’s cleanliness requirements,” explains technician Alan Dowson.
“To check the effectiveness of this process, the swabs are subjected to a comparable heat shock and then cultivated for 72 hours, to analyse the number of spores and bacteria able to survive. The viable bioburden is then calculated for the surface area of the WISDOM antenna. If this level is below the mission’s maximum then it is cleared for delivery.”
All the cleanroom’s air passes through a two-stage filter system. Anyone entering the chamber has to gown up in a much more rigorous way than a hospital surgeon, before passing through an air shower to remove any remaining contaminants.
The chamber’s cleanliness is such that it contains less than 10 particles smaller than a thousandth of a millimetre per cubic metre. A comparable sample of the outside air could well contain millions.
By international planetary protection agreement, space agencies are legally required to prevent terrestrial microbes hitchhiking to other planets and moons in our Solar System where past or present alien life is a possibility.
Asteroid 162173 Ryugu
After a 42-month journey, Japan's Hayabusa2 spacecraft arrived at asteroid 162173 Ryugu, 300 million km from Earth, on 27 June at 02:35 CEST (00:35 GMT).
This remarkable achievement was confirmed when the spacecraft closed to just 20 km from the 1 km-diameter asteroid's surface, having entered a critical phase of this ambitious mission.
This image was taken on 24 June, as the craft nosed up to the asteroid, from a distance of about 40 km.
Hayabusa2 aims to study Ryugu in detail, deposit a European and a series of Japanese landers on the surface and return a sample of ancient rock to Earth in 2020.
"Together with all of you, we have become the first eyewitnesses to see asteroid Ryugu. I feel this amazing honour as we proceed with the mission operations," said Yuichi Tsuda, project manager from the Japan Aerospace Exploration Agency (JAXA).
In 2014-17, during Hayabusa2's cruise phase from Earth to the asteroid, ESA's deep-space ground station at Malargüe, Argentina − part of the Agency's worldwide Estrack network − provided crucial communication support to the mission.
In July this year, Malargüe will resume support, providing one communication contact session per week together with ESA's Cebreros station in Spain. Malargüe station will also support the ESA-JAXA BepiColombo mission, due for launch in the autumn.
Cassini narrow-angle camera image looking across the south pole of Saturn's icy moon Enceladus on 30 November 2010, 1.4 years after southern autumnal equinox. Material sprays from cracks in the moon's icy surface known as 'tiger stripes'. The shadow of the body of Enceladus on the lower portions of the jets is clearly seen.
The image scale is 390 m/pixel and the Sun-Enceladus-spacecraft angle is 162.5 degrees. This image was first published 28 July 2014.
ExoMars Trace Gas Orbiter showing the region where the ancient Uzboi Vallis enters Holden crater in the southern hemisphere of Mars. The valley begins on the northern rim of the Argyre basin and was formed by running water. The fluvial deposits are clearly visible in the impact cratered terrain.
The image was taken by the orbiter’s Colour and Stereo Surface Imaging System, CaSSIS on 31 May 2018 and captures an approximately 22.7 x 6.6 km segment centred at 26.8ºS/34.8ºW. North is to the bottom left in this orientation.
Official launch of ESERO Luxembourg with representatives from ESA, Ministry of Economy, Minister of Education, Children and Youth; and representatives of the Luxembourg Science Center
The BepiColombo Mercury Planetary Orbiter (MPO) with the first part of the multi-layered insulation fitting completed. The white outer layer is a high-temperature blanket to protect the spacecraft from the extreme thermal conditions that will be experienced in Mercury orbit.
The joint ESA-JAXA mission comprises two scientific orbiters – ESA's Mercury Planetary Orbiter and JAXA's Mercury Magnetospheric Orbiter – that will be carried to the innermost planet by the Mercury Transfer Module. Launch preparations are taking place at Europe's Spaceport in Kourou. The launch window is open 5 October – 29 November.
This artist’s rendition of time in space captures the movement, drama, and complexity of this cosmic abstraction.
Time is infamously relative. Whether an activity takes seconds or hours depends on your point of view. For astronauts living off-planet and experiencing roughly 16 sunrises and sunsets a day, the concept of time is even more warped. If astronauts float through space, do they also cruise through an altered sense of time?
Since perceptions of time and space are believed to share the same neural processes, and research on depth perception in weightlessness has shown that astronauts often underestimate distance, scientists speculate that for astronauts time also flies in space.
The Time experiment on the International Space Station investigates the claim that time subjectively speeds up in microgravity. ESA astronaut Alexander Gerst performed the experiment for the first time last week and will do so again throughout his Horizons mission.
Astronauts gauge how long a visual target appears on a laptop screen and their reaction times to these prompts recorded to process speed and attention.
Scientists are not only collecting data on the neurological mechanisms at work here. The relativity of time, after all, implies that it is all in your head. As much as we can objectively measure and plot time, how individual humans perceive it is not just neurological but also psychological.
This is an important factor to life both on and off Earth.
Space is and always will be a harsh environment for humans. As homey as the Space Station tries to be, it is light years away from the known comforts of home on Earth. Naturally, this can affect mental health and in turn their cognitive abilities. Being alert and focused in space is crucial to safety. An astronaut misjudging time can delay reaction and risk the safety and success of crews and missions.
Understanding these neurological and psychological triggers that warp our sense of time means countermeasures can be developed to calibrate our mental clocks.
Bringing these countermeasures down to Earth could improve the lives of those who suffer from isolation or confinement, whether real or perceived: the elderly and bedridden, people working shifts or in isolation, mentally-ill patients, and the incarcerated.
Official opening of the International Space University’s Space Studies Program on 25 June 2018, at ESA in the Netherlands.
The opening ceremony was attended by HM the King of the Netherlands and addressed by ESA Director General Jan Wörner.
The nine-week programme will see more than 130 participants representing 37 nationalities take part in lectures, workshops and team projects to gain an interdisciplinary understanding of all aspects of the space industry.
This year’s ISU programme is co-hosted by the Technical University Delft and the Netherlands Space Office, in close cooperation with ESA and Leiden University.
Two groups of participants will focus in particular on issues of space safety and sustainability as they prepare project reports on the role space should play in human adaptation to global climate change and on new ideas for the removal of space debris from Earth orbit using ecologically sound technology.
ESA’s Aeolus wind satellite set sail from France on 15 June 2018 for its launch site in French Guiana. With arrival expected to be 28 June, this latest Earth Explorer mission still has to spend another few days on the ocean waves.
This rich and dense smattering of stars is a massive globular cluster, a gravitationally-bound collection of stars that orbits the Milky Way. Globular clusters are denser and more spherical than open star clusters like the famous Pleiades. They typically contain hundreds of thousands of stars that are thought to have formed at roughly the same time.
Studies have shown that this globular cluster, named NGC 6139, is home to an aging population of stars. Most globular clusters orbiting the Milky Way are estimated to be over 10 billion years old; as a result they contain some of the oldest stars in our galaxy, formed very early in the galaxy’s history. However, their role in galactic evolution is still a matter of study.
This cluster is seen roughly in the direction of the centre of the Milky Way, in the constellation of Scorpius (The Scorpion). This constellation is a goldmine of fascinating astronomical objects. Hubble has set its sights on Scorpius many times to observe objects such as the butterfly-like Bug Nebula, surprising binary star systems, and other dazzling globular clusters.
Week In Images
25 - 29 June 2018