Sometimes it requires a step back in order to see a pattern...#BlueDot
Image taken by ESA astronaut Alexander Gerst aboard the International Space Station, during his Blue Dot mission. August 2014
More images from his Blue Dot mission in his Flickr gallery: https://www.flickr.com/photos/astro_alex
Rosetta navigation camera image taken on 23 August 2014 at about 61 km from 4 km-wide comet 67P/Churyumov-Gerasimenko. From 23 August, Rosetta started taking NAVCAM image sequences as small 2 x 2 rasters, such that roughly one quarter of the comet is seen in the corner of each of the four images, rather than all in just one shot. This is one example of the 512 x 512 pixel ‘corner’ image.
Read more on the blog: CometWatch update
Astronomers studying SN2014J, a Type Ia supernova discovered in January 2014, have found proof that this type of supernova is caused by a white dwarf star reigniting and exploding.
This finding was made by using ESA’s Integral observatory to detect gamma rays from the radioactive elements created during the explosion.
This sequence of artist's impressions shows some of the steps leading up to and following the explosion.
A white dwarf, a star that contain up to 1.4 times the mass of the Sun squeezed into a volume about the same size as the Earth, leeches matter from a companion star (image 1). The Integral measurements suggest that a belt of gas from the companion star builds up around the equator of the white dwarf (image 2). This belt detonates (image 3) and triggers the internal explosion that becomes the supernova (image 4). Material from the explosion expands (image 5) and eventually becomes transparent to gamma rays (image 6).
"Rosetta, are we there yet?" mosaic comprising a selection of the photos submitted to the competition, in the shape of Rosetta and Comet 67P/Churyumov-Gerasimenko.
Here on Earth, under the protection of the layers of our atmosphere, we can still find the heat from the Sun sometimes almost unbearable. This is also a problem for space-based telescopes like the James Webb Space Telescope (JWST).
Once in its operational orbit, JWST will be exposed directly to the Sun’s intense glare – not ideal when most of JWST needs to be kept at very cool, infrared-friendly temperatures. To cater for this, the observatory needs to be equipped with a protective parasol.
The kite-shaped piece of foil shown here is the sunshield test unit for JWST. This image captures the first time the deployment of the sunshield was fully and successfully tested, at a cleanroom in the Northrop Grumman facility in Redondo Beach, California, USA, during the first week of July 2014.
This sunshield is the largest part of JWST and offers intense protection from the Sun, letting through less than a millionth of the Sun’s heat! This massive parasol is as long as a tennis court, but incredibly light. It is composed of five super-thin membranes that will separate and unfurl into a precise arrangement once the telescope is in space. During launch, this shield will be folded up like an umbrella to fit neatly around the telescope’s mirrors and other instruments within the Ariane 5 rocket fairing.
When unfurled, the sunshield will protect JWST’s ‘cold’ side, where very sensitive infrared instruments are located inside the Integrated Science Instruments Module, maintaining a thermally stable cold environment, around –233 ºC!
Thanks to the sunshield, these low temperatures are reached passively, without the help of any active cooling system, by radiating heat into deep space. Just one of JWST's instruments, the Mid-Infrared Instrument (MIRI), will be cooled even further by a dedicated cryogenic cooler, reaching around –266 ºC. Although parts of JWST will reach such low temperatures, the shield will create a thermal barrier so that on JWST’s ‘hot’ side, the spacecraft electronics can work at room temperature.
Unlike its predecessor, the Hubble Space Telescope, JWST does not have a baffle protecting its optics from unwanted incoming light. This makes the sunshield’s role even more important because it will not only block heat, but also unwanted light, allowing JWST to operate to the best of its near-infrared capabilities.
When completed, JWST will be the most powerful space observatory ever built. JWST is an international collaboration between NASA, ESA and the Canadian Space Agency.
ESA trainers and caving specialists are pictured here underground in Sardinia, Italy, to setting the scene for space-like astronaut training next month. The trainers descended into the caves on a ‘dry run’ without the astronauts, to test their planned tasks and operations, and are now finalising preparation of equipment and facilities after ESA declared ‘GO’ for CAVES 2014 last week.
CAVES 2014 will take place between 7–20 September in Sardinia – details on participants in this year’s event can be found here.
CAVES – short for Cooperative Adventure for Valuing and Exercising human behaviour and performance Skills – offers astronauts, trainers and planners a chance to test space-like procedures while exploring uncharted caverns in new environments.
This year, the CAVES team are stepping up the space realism and exploration while testing more technology and procedures.
Clambering down to basecamp hundreds of metres below the surface using safety tethers is similar to conducting a spacewalk, and this year the procedures have been updated to include astronaut terminology.
In space, an object can quickly float away and be lost forever. While caving, dropped equipment can also be lost forever down crevices or in holes.
When passing equipment, cavers and astronauts must make sure the recipient is grasping the item before the first person lets go: ‘make before break’ in astronaut language.
No opportunity is missed to make the week-long stay underground resemble a space mission. The trainees will follow timeline and procedures, including handling equipment and communication protocols just as on the International Space Station.
Five candidate sites were identified on Comet 67P/Churyumov-Gerasimenko during the Landing Site Selection Group meeting held 23–24 August 2014. The approximate locations of the five regions are marked on these OSIRIS narrow-angle camera images taken on 16 August from a distance of about 100 km. The comet nucleus is about 4 km across.
The sites were assigned a letter from an original pre-selection of 10 possible sites identified A through J. The lettering scheme does not signify any ranking. Three sites (B, I and J) are located on the smaller of the two lobes of the comet and two sites (A and C) are located on the larger lobe.
Read more in Rosetta: Landing site search narrows
Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
A fluorescent microscopic view of cells from a type of bone cancer, being studied for a future trip to deep space – aiming to sharpen our understanding of the hazardous radiation prevailing out there.
Today’s astronauts orbiting close to Earth are protected from most space radiation by our planet’s atmosphere and magnetic field.
In future, astronaut missions are planned to Mars and beyond. But heading farther out to space would increase crews’ radiation exposure, not just from the charged particles expelled by our own Sun but also the heavy ions thrown out by the rest of the cosmos, known as ‘galactic cosmic radiation’.
Concern is greatest around the 1% of cosmic radiation nuclei the size of an iron atom or more – known as ‘high-ionising high-energy particles’ or HZE for short.
Accelerated close to light speed by magnetic fields as they cross the Universe, HZEs can slice right through DNA. The most serious class of damage is termed ‘double-strand breaks’, leading to loss of genetic information and potentially triggering cancer
“However cells do have an ability to repair double-strand breaks, and this is what we want to study,” explains Yassen Abbas, a young graduate trainee at ESA’s Life, Physical Science and Life Support Laboratory.
“The aim is to follow the repair process in real time; the cells we are using have a marker which will express a dedicated fluorescent fusion protein, allowing us to monitor the formation of DNA repair.”
The test subjects are osteosarcoma cells – a type of bone cancer – that have been selected because of their rapid growth characteristics. “The more cells per sample, the higher the chance of observing a radiation event,” adds Yassen.
The proposed experiment would include a camera to trace the progress of the repair process, returning images to the ground in real time.
But this isn’t an experiment that can be done on the International Space Station, or anywhere else in low-Earth orbit. Instead the proposed payload will have to be placed in deep space, while also keeping the cell samples alive and comfortable.
Yassen has been working on the practicalities of achieving this on a fully automated basis.
He adds: “At one time we were planning to fly as a passenger on ESA’s now-cancelled Lunar Lander. As an alternative, missions to other deep-space destinations could be considered, or else a dedicated CubeSat.”
The image has been fluorescently stained to visualise the cells’ nuclei in blue and their surrounding cytoskeleton in red. The image covers a length of approximately 305 micrometres (equivalent to 0.305 millimetres) The scale bar measures 25 micrometres across.
This new NASA/ESA Hubble Space Telescope image shows a variety of intriguing cosmic phenomena.
Surrounded by bright stars, towards the upper middle of the frame we see a small young stellar object (YSO) known as SSTC2D J033038.2+303212. Located in the constellation of Perseus, this star is in the early stages of its life and is still forming into a fully grown star. In this view from Hubble’s Advanced Camera for Surveys (ACS) it appears to have a murky chimney of material emanating outwards and downwards, framed by bright bursts of gas flowing from the star itself. This fledgling star is actually surrounded by a bright disc of material swirling around it as it forms — a disc that we see edge-on from our perspective.
However, this small bright speck is dwarfed by its cosmic neighbour towards the bottom of the frame, a clump of bright, wispy gas swirling around as it appears to spew dark material out into space. The bright cloud is a reflection nebula known as [B77] 63, a cloud of interstellar gas that is reflecting light from the stars embedded within it. There are actually a number of bright stars within [B77] 63, most notably the emission-line star LkHA 326, and its very near neighbour LZK 18.
These stars are lighting up the surrounding gas and sculpting it into the wispy shape seen in this image. However, the most dramatic part of the image seems to be a dark stream of smoke piling outwards from [B77] 63 and its stars — a dark nebula called Dobashi 4173. Dark nebulae are incredibly dense clouds of pitch-dark material that obscure the patches of sky behind them, seemingly creating great rips and eerily empty chunks of sky. The stars speckled on top of this extreme blackness actually lie between us and Dobashi 4173.
Week In Images
25-29 August 2014