Tag Archives: ESA

Rosetta gets stoned

9 Oct comet67p_navcamfeb3

Last week saw a dramatic end to one of the most influential space missions in recent decades. At 11:19am GMT on September 30th the Rosetta spacecraft crash landed on the surface of Comet 67P/Churyumov-Gerasimenko to the cheers and jeers of scientists and engineers from the European Space Agency (ESA) and German Aerospace Center (DLR).

Back in early March 2004 spacecraft Rosetta, and assistant lander Philae, launched from the Guiana Space Centre in South America with a mission to map the surface and composition of Comet 67P.

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After over ten years of transit, Rosetta finally rendezvoused with the comet in August 2014 having passed a number of asteroids and the planet Mars. Throughout the 720 million kilometre journey the spacecraft’s array of instruments were cataloguing data as well as gathering a library of 116,000 images.

Probe lander Philae created history when it detached from its carrier on November 12th 2014 and touched down after bouncing twice on the comet’s surface. Once located relatively unscathed at the bottom of a crater wall, Philae could begin to send vital data back to Earth via Rosetta. The probe pieced together the molecular structures of the comet’s atmosphere and soil for a further three days until its battery was depleted.

Rosetta continued its work after the loss of Philae and the spacecraft was able to relay important evidence for another 23 months. Evidence such as the signature of water vapour, making up some of the comet’s structure, was found to be vastly different to that on Earth. Bringing scientists to the conclusion that the globe’s oceans were not delivered via these types of objects.

After 12 years and 7 billion kilometres travelled it was time for Rosetta’s final farewell. Last Friday (September 30th) ground crew at DLR’s facility in Darmstadt, Germany deliberately drove the vehicle in to the comet it had been so closely monitoring.  Emotions were running high as the team awaited imagery and information of the declination.

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Image courtesy of theweathernetwork.com

Even now that ESA and DLR scientists have called an end to Rosetta’s career, the mission directors are saying there is so much more to come.

“We have only scratched the surface of the science, there is decades worth of data here.”
– Matt Taylor, Rosetta Project Scientist

A selection of spectacular images captured by Rosetta can be found on the ESA website.

VENUS EXPRESS Finds Ozone on Earths Twin

11 Oct Venus and its orbiting satellite

A satellite orbiting Venus has found that the planet has an Ozone layer similar to that of Earth’s. Useless to a planet as hot and dead as tortured Venus you might think… but what does this mean for Earths ‘twin’ planet and Earth it self?

Venus is a world quite similar to that of our own except the features that really matter for that of life to exist are so different. Venus is known as Earths ‘twin’ mainly because their size is almost identical and due to the fact it has an atmosphere high above its surface full of the common gases we depend on.

Venus orbits the sun 67 million miles away, which is over 25 million miles away from Earth. Being that close to our host star keeps temperatures soaring to 464 degrees Celsius, the hottest of any of the other seven planets.

The planet stays this hot due to the thick atmosphere layer that sits high above its surface trapping 80% of the sunlight that strikes it warming the gases inside. Venus’ heavy cloud coating is 96% carbon dioxide, which consists of three distinctive layers of Sulphuric Acid decreasing in density as you reach the boiling surface. With such a harmful array of gases how is it possible for the one we rely on to be formed?

An Ozone layer is a smaller, more delicate lining, to that of atmosphere, which covers planetary systems that produce significant levels of oxygen. Ozone is the name given to a molecule of three oxygen atoms (O3) that combine when sunlight does penetrate the concentrated poisonous atmosphere. The atoms are thrown together when the winds on Venus thrash continually around the dead body.

These ‘Ozone’ layers have only previously been detected on the Earth and its other next door neighbor Mars. On Earth this layer absorbs much of the sun’s harmful ultraviolet waves, which protect us from radiation along with the magnetic field and atmosphere. What is also believed is that the suns high level of solar rays enabled the creation of life supportive of oxygen.

This discovery of ozone by the Venus Express orbiter, and the previous acknowledgement of carbon dioxide and oxygen within the planets atmosphere, leads scientists to believe that finding other worlds that tick these biological boxes will aid the slimming down process when looking for both microbial and complex life.

[COSMIC BODIES] – Galaxies Far Far Away

19 Sep UDFj-39546284 appears as the extremely faint red spot, Centre image

When humans think about distances in space, it is almost impossible to comprehend the vast expanse in between different masses. In a humans mind circumnavigating the globe is a huge deal, the time it would take is almost inconceivable let alone the distance. Scientists however will continue to strive in order to see further into the universe and therefore longer back in time. Images are just starting to reach us of some of the oldest known bodies within the universe and lots more discoveries are sure to come; hopefully with the notion of letting us understand where we come from.

Until recently the oldest known objects in space, except the universe itself, have thought to be stars, or gamma ray bursts as these stars explode, but now there is evidence to suggest that the galaxies, containing these stars are much older than thought previously. The universal limit for age is set by the boundaries of the universe, which is considered to be as old as 13.75 billion years old. These galaxies come pretty close to this age, in astrological terms.

Galaxies consist of a huge collection of stars orbiting a central core; this is thought to be a super-massive black hole, although this is not yet official. Galaxies range in sizes, our galaxy, the ‘Milky Way’, is thought to contain between 100 billion and 400 billion stars. Our closets neighboring galaxy ‘Andromeda’ is thought to have a mass of three trillion stars with a diameter of 250,000 light-years.

A light year is a measurement of distance, unsurprisingly, the distance it takes light to travel in one year. Light travels at a speed of 186,000 miles per second that is 671 million miles an hour. Keep that astronomical speed in mind as we delve further into the cosmos.

In September 2009 a group of astronomers handling the ‘Hubble Ultra Deep Field Telescope’ (HUDF) came across what was soon to be spectroscopically confirmed as the furthest, and therefore the oldest, object to be discovered in the universe.

What the scientist had found was a galaxy some 13.1 billion light-years away, meaning it was only 600 million years younger than the universe itself.  Scientists believe that galaxies only start to form at a limit of 200 million years after the Big Bang, meaning that this galaxy was formed during what is known as the ‘Reionization Epoch’, a period in which galaxies were forming at the fastest rate.

This galaxy was soon to be named by those who found it as UDFy-38135539 or HUDF.YD3 and it even featured on the television series presented by Professor Brian Cox, ‘Wonders of the Universe’.

Arguably it is a small galaxy registering one billion stars that covers just one- tenth the diameter of the Milky Way. However when thinking about those numbers it gives even the experienced travellers amongst us severe jet lag.

Now here is the even more exciting bit…

As soon as January of the next year an even older galaxy was discovered and this now holds the record for the oldest known object in the cosmos. Similarly named UDFj-39546284 is roughly 150 millions years older than the previous, although it has not yet been spectroscopically verified.

It is thought confirmation of this galaxy will occur when NASA and ESA launch the James Webb Space Telescope (JWST) planned for 2018. ESA also have another telescope in range in which they hope to have operational at the beginning of the next decade. The European-Extremely Large Telescope (E-ELT) will help us not only understand how galaxies and planets are formed but should aid us in looking into the recesses of the universe in a hope to understand where we came from and ultimately where we are going.

[COSMIC BODIES] – Frozen Oceans

12 Aug Water plumes ejecting from 'tiger stripes' on Enceladus

Ever since man first started to gaze out into the skies, he has always wondered if he is alone. Is life possible among the millions of stars he could see or even just in this small band of planets we call the Solar System? Ever since man has had the aid to his eyes and knowledge of science, he has been able to come closer to the conclusion of that question.

Places like Mars and The Moon (Lunar) have always had romanticisms about alien life living on their surfaces, and as of yet we are still to proven wrong. I’d like to introduce two more alluring worlds among our Solar System that show decent signs of a habitat for E.T.

These worlds are far out into the more inhospitable regions of our host star system; they both orbit huge gas giant planets and both have a temperature that is lower than -150 degrees Celsius.

These worlds are the small icy Moons; Europa, who orbits Jupiter, and Enceladus, who’s host planet is Saturn. These worlds, although some distance apart, share a few similarities in the essential aspects for them to support life. Both moons share the most important of these, water, and lots of it. In fact, Enceladus is believed to be made up of 91% water vapor.

As a species we know that water is an essential building block for life, you only have to look around you for proof. So it seems entirely plausible that these moons can be the habitat for some bizarre marine life as there is already so much of it here on Earth.

Enceladus is a tiny moon, smaller than Great Britain, which sits in the E-ring of the planet Saturn, over 147,000 miles away from its host. Discovered in 1789 by William Herschel, the man who also discovered Uranus, Enceladus is the sixth moon of Saturnian orbit and the brightest object in the solar system. Believed to reflect 99% sunlight off its surface, Enceladus is small but an incredible find. Scientists are excited about this moon because of it’s surface appearance and subterranean goings-on.

In 2005 a probe named ‘Cassini’ was sent passed Enceladus with instructions to take photographs. The satellite took some amazing images of giant jets of liquid water protruding into outer space some 80 miles. This indicated the presence of liquid water and the possibility of a subterranean ocean beneath its icy surface.

The area of interest became known as the ‘tiger stripes’, a series of linear depressions on the surface indicating a raised temperature in the south Polar Regions. This proved the presence of an ice volcano fuelled by underground heat.

‘This finding is a crucial new piece of evidence showing that environmental conditions favorable to the emergence of life can be sustained on icy bodies orbiting gas giant planets’ – Nicolas Altobelli, ESA project scientist for Cassini.

No impact craters in the surrounding area also implies that this region is young, therefore ever changing. A spectacle this moon shares with her step-sister Europa.

Jupiters moon Europa

Europa is a Jovian moon, meaning it orbits within the realms of Jupiter, and is also one of four of the Galilean moons. Named by Galileo Galilei, in respect to a Greek queen, Europa was discovered in 1610, along with the three other closets moons to Jupiter. Although somewhat bigger than Enceladus, Europa is still smaller than our moon but with a high potential to preserve life due to its huge ocean. Scientists believe the surfaces layer, some -160 degrees Celsius, is tens of kilometers thick and the water layer below is thought to be 50 -105 kilometers deep, that’s more water than Earths oceans combined.  This leads scientists to believe that the shear size of the ocean underneath, in comparison to the size and diversity to life on Earth, that life on Europa is a mathematical certainty.

‘we calculate that the odds of finding life in the waters of Europa are 122 out of 123. The 122 known bodies of saltwater harbor microbial life. The 123rd body of saltwater, Europa’s vast ocean, is the body that has yet to be tested. Therefore, the odds are 122 of 123 in favor of finding life, or above 99%’– David Darling, part time astronomer and science writer.

Europa is close to Jupiter, so close that the massive planet exerts tidal pressures on the moon much like the relationship the Earth has with it’s lunar neighbour. This causes ‘plates’ on the moons surface to crack and move due to warm temperatures below the surface most probably caused by underwater hydrothermal vents.

This below surface phenomena is also true of Enceladus and as we recently discovered, on our planet, life does not necessarily require sunlight to exist.

Hydrothermal vents were discovered just in the last decade, they prove that life can go on without heat provided for it by the Sun. These vents send columns of water reaching temperatures of 460 degrees Celsius from the core and out into the depths of our oceans. Crabs, worms and bacteria like creatures were discovered to be living within this eco-system and thriving well without sunlight. It was clearly all down to these vents and the heat they were giving off that allowed complex life to live in such an extreme enviroment. Now scientists were excited because they thought that this could just as easily be true of any other body supporting water or water ice.

Underwater Hydrothermal Vents

So scientists from NASA and the European Space Agency (ESA) went on the hunt for worlds that looked like a suitable home for these hydrothermal vents and their answers were both Europa and Enceladus.

As mentioned before Enceladus has a satellite nearby already, named Cassini after the Italian/French astronomer of the 17th and 18th century. Launched in 1997 Cassini has beamed back tons of information surrounding Saturn and her moon system and will continue to do so for the 20-year duration of its mission.

ESA and NASA also had a similar, but far more advanced, probe that was scheduled for launch in 2020 in order to understand Jupiter’s moons Europa and Ganymede. NASA have since pulled out of the mission called, Europa Jupiter System Mission (EJSM) and have left ESA to fund its own quest to the region, Jupiter Icy Moon Explorer (JUICE).

Russian interests have also spurred this assignment forwards as they look to actually having a lander set up home on the moon. In an attempt to understand Europa’s icy surface and subterranean ocean the Europa Lander will be separated from the main rocket in order to carry out various fly-by missions. This launch looks likely to be scheduled far beyond its original date of 2020.

Until this mission we still have a lot to understand about both these moons complexity and intriguing imagery. They both leave us wondering just what lies beneath their surfaces and how much of it is Alien and how much is familiar.

For Galileo to have gazed up and wondered so much and known so little speaks the same of us today. With his help, along with Herschel and the understanding of the critical aspects of life, we can envisage, like Galileo did, the grandeur of celestial knowledge while still understanding so little.