esa Archives

October 1, 2012December 23, 2015 by Nancy Atkinson

Surprise! Hot Venus has a Cold Upper Atmosphere

Venus’ terminator – the transitional region between day and night — may fuel an unusually cold region in the atmosphere. Credit: ESA/MPS, Katlenburg-Lindau, Germany

The hottest planet in the Solar System has a surprisingly cold region high in the planet’s atmosphere, according to new findings by the Venus Express spacecraft. While surface temperatures on this hot and hostile planet tops out at 735 Kelvin, or 462 degrees Celsius, ESA scientists say that a layer in the atmosphere about 125 km up has temperatures of around –175 degrees C, and may be cold enough for carbon dioxide to freeze out as ice or snow.

This means this curious cold layer is much colder than any part of Earth’s atmosphere even though Venus is known for its dense, blistering atmosphere and is much closer to the Sun. Additionally, the cold layer appears to be affected by the transitioning between day and night on Venus.

Scientists made the discovery by watching as light from the Sun filtered through the atmosphere to reveal the concentration of carbon dioxide gas molecules at various altitudes along the terminator – the dividing line between the day and night sides of the planet.

Then they combined data about the carbon dioxide concentration with data on atmospheric pressure at each height. The scientists could then calculate the corresponding temperatures.

“Since the temperature at some heights dips below the freezing temperature of carbon dioxide, we suspect that carbon dioxide ice might form there,” said Arnaud Mahieux of the Belgian Institute for Space Aeronomy and lead author of the paper reporting the results in the Journal of Geophysical Research.

The temperature profile along the terminator for altitudes of 70–160 km above the surface of Venus. Credit: ESA/AOES–A.V. Bernus

Source: ESA

Clouds of small carbon dioxide ice or snow particles should be very reflective, perhaps leading to brighter than normal sunlight layers in the atmosphere.

“However, although Venus Express indeed occasionally observes very bright regions in the Venusian atmosphere that could be explained by ice, they could also be caused by other atmospheric disturbances, so we need to be cautious,” said Mahieux.

The study also found that the cold layer at the terminator is sandwiched between two comparatively warmer layers.

“The temperature profiles on the hot dayside and cool night side at altitudes above 120 km are extremely different, so at the terminator we are in a regime of transition with effects coming from both sides.

“The night side may be playing a greater role at one given altitude and the dayside might be playing a larger role at other altitudes.”

Similar temperature profiles along the terminator have been derived from other Venus Express datasets, including measurements taken during the transit of Venus earlier this year.

Models are able to predict the observed profiles, but further confirmation will be provided by examining the role played by other atmospheric species, such as carbon monoxide, nitrogen and oxygen, which are more dominant than carbon dioxide at high altitudes.

“The finding is very new and we still need to think about and understand what the implications will be,” says Håkan Svedhem, ESA’s Venus Express project scientist. “But it is special, as we do not see a similar temperature profile along the terminator in the atmospheres of Earth or Mars, which have different chemical compositions and temperature conditions.”

September 29, 2012December 23, 2015 by Nancy Atkinson

ESA’s Big Cargo Ship Departs from the Space Station

The view when ATV-3 approached the ISS in 2012. Credit: NASA.

After a three-day delay, the European Space Agency’s “Edoardo Amaldi” Automated Transfer Vehicle (ATV-3) undocked from the aft port of the International Space Station’s Zvezda service module at 21:44 UTC (5:44 p.m. EDT) on Friday.

Tuesday’s initial attempt to undock the European cargo ship was called off due to a communications error between the Zvezda module’s proximity communications equipment and computers on the ATV. Russian flight controllers resolved the problem, but then an additional delay occurred because of the possibility of two pieces of space debris coming close to the ISS, and the ATV would have been used to perform an avoidance maneuver; however, it was later deemed the debris posed no threat.

Image of the ATV-3 when it reached the International Space Station on March 28, 2012. Credit: NASA TV

Expedition 33 Flight Engineers Yuri Malenchenko and Aki Hoshide, who together closed up the hatches to ATV-3 Monday, monitored its automated departure from a control panel inside Zvezda. Meanwhile, Commander Suni Williams photographed the departing space freighter to document the condition of its docking assembly.

ATV-3, now filled with trash and unneeded items, backed away to a safe distance from the orbiting complex after undocking. Once it reaches distance about 4,500 miles in front of the station, the European cargo craft will fire its engines twice on Tuesday, Oct. 2, to send it into the Earth’s atmosphere for a planned destructive re-entry that evening. As the ATV-3 plunges back to the Earth, the Re-Entry Breakup Recorder that Hoshide installed inside the vehicle will collect and transmit engineering data to enhance the efficiency of spacecraft designs and minimize the hazards to people and property on the ground even in the case of an uncontrolled re-entry for future cargo ships.

“Edoardo Amaldi,” named for the 20th-century Italian physicist regarded as one of the fathers of European spaceflight, delivered 7.2 tons of food, fuel and supplies to the orbiting complex after docking to the station March 28. The fourth ATV, named “Albert Einstein,” is slated to launch in April 2013. More than 32 feet long — about the size of a traditional London double-decker bus – the ATV is the largest and heaviest vehicle that provides cargo resupply for the station.

September 20, 2012December 23, 2015 by Jenny Winder

Gaia Mission Passes Vital Tests

Caption: Fully integrated Gaia payload module with nearly all of the multilayer insulation fabric installed. Credit: Astrium SAS

Earlier this month ESA’s Gaia mission passed vital tests to ensure it can withstand the extreme temperatures of space. This week in the Astrium cleanroom at Intespace in Toulouse, France, had it’s payload module integrated, ready for further testing before it finally launches next year. This is a good opportunity to get to know the nuts and bolts of this exciting mission that will survey a billion stars in the Milky Way and create a 3D map to reveal its composition, formation and evolution.

Gaia will be operating at a distance of 1.5 million km from Earth (at L2 Lagrangian point, which keeps pace with Earth as we orbit the Sun) and at a temperature of -110°C. It will monitor each of its target stars about 70 times over a five-year period, repeatedly measuring the positions, to an accuracy of 24 microarcseconds, of all objects down to magnitude 20 (about 400,000 times fainter than can be seen with the naked eye) This will provide detailed maps of each star’s motion, to reveal their origins and evolution, as well as the physical properties of each star, including luminosity, temperature, gravity and composition.

The service module houses the electronics for the science instruments and the spacecraft resources, such as thermal control, propulsion, communication, and attitude and orbit control. During the 19-day tests earlier this month, Gaia endured the thermal balance and thermal-vacuum cycle tests, held under vacuum conditions and subjected to a range of temperatures. Temperatures inside Gaia during the test period were recorded between -20°C and +70°C.

“The thermal tests went very well; all measurements were close to predictions and the spacecraft proved to be robust with stable behavior,” reports Gaia Project Manager Giuseppe Sarri.

For the next two months the same thermal tests will be carried out on Gaia’s payload module, which contains the scientific instruments. The module is covered in multilayer insulation fabric to protect the spacecraft’s optics and mirrors from the cold of space, called the ‘thermal tent.’

Gaia contains two optical telescopes that can precisely determine the location of stars and analyze their spectra. The largest mirror in each telescope is 1.45 m by 0.5 m. The Focal Plane Assembly features three different zones associated with the science instruments: Astro, the astrometric instrument that detects and pinpoints celestial objects; the Blue and Red Photometers (BP/RP), that determines stellar properties like temperature, mass, age, elemental composition; and the Radial-Velocity Spectrometer (RVS),that measures the velocity of celestial objects along the line of sight.

The focal plane array will also carry the largest digital camera ever built with, the most sensitive set of light detectors ever assembled for a space mission, using 106 CCDs with nearly 1 billion pixels covering an area of 2.8 square metres

After launch, Gaia will always point away from the Sun. L2 offers a stable thermal environment, a clear view of the Universe as the Sun, Earth and Moon are always outside the instruments’ fields of view, and a moderate radiation environment. However Gaia must still be shielded from the heat of the Sun by a giant shade to keep its instruments in permanent shadow. A ‘skirt’ will unfold consisting of a dozen separate panels. These will deploy to form a circular disc about 10 m across. This acts as both a sunshade, to keep the telescopes stable at below –100°C, and its surface will be partially covered with solar panels to generate electricity.

Once testing is completed the payload module will be mated to the service module at the beginning of next year and Gaia will be launched from Europe’s Spaceport in French Guiana at the end of 2013.

Find out more about the mission here

August 3, 2012January 5, 2016 by John Williams

Zoom into an Ancient and Fractured Martian Landscape

Mars! Martian meteorites make their way to Earth after being ejected from Mars by a meteor impact on the Red Planet. Image: NASA/National Space Science Data Center.

Peer at this new image of Mars’ Ladon Basin and you get some notion of the violence that took place during the early history of Mars.

ESA’s Mars Express imaged the southern part of the partially buried crater informally known as Ladon Basin. The basin is the site of an ancient impact which is about 440 kilometers (273 miles) across. On an earthly scale, Ladon Basin would stretch from London to Paris or fill up most of Colorado.

These zoomable images allows you to quickly zoom into whatever part of the picture you want to see close up. Just slide the scale (between the plus and minus sign) at the bottom of the application to zoom in.

Continue reading “Zoom into an Ancient and Fractured Martian Landscape”

July 27, 2012December 23, 2015 by Jason Major

Europe’s Plans to Visit the Moon in 2018

The European Space Agency is aiming for the Moon with their Lunar Lander mission, anticipated to arrive on the lunar surface in 2018. Although ESA successfully put a lander on Titan with the Huygens probe in 2005, this will be the first European spacecraft to visit the surface of Earth’s Moon.

Although Lunar Lander will be an unmanned robotic explorer, the mission will be a forerunner to future human exploration of the Moon as well as Mars. Lunar Lander will use advanced technologies for autonomous landing and will be able to determine the best location for touchdown on its own, utilizing lasers to avoid obstacles on the Moon’s surface.

With no GPS on the Moon, Lunar Lander will navigate by digitally imaging the surface on the fly. Landing will be accomplished via thrusters, which were successfully tested earlier this year at a test chamber in Germany.

Lunar Lander’s destination will be the Moon’s south pole, where no exploration missions have ever landed. Once on the lunar surface, the Lander will investigate Moon dust using a robotic arm and a suite of onboard diagnostic instruments, sending data and images back to scientists on Earth for further study.

Watch a video of the Lunar Lander mission below, from launch to landing.

Read more about Lunar Lander on the ESA site here.

Images and video: ESA

July 12, 2012December 23, 2015 by Jenny Winder

Space Junk: Ideas for Cleaning up Earth Orbit

Caption: Artist’s impression of debris in low earth orbit Credit: ESA

Space may be big — vastly, hugely, mind-bogglingly big — but the space around Earth is beginning to get cluttered with space junk. This poses a threat, not only to other satellites, space stations and missions, but to us here on Earth as well. While we wrestle with environmental issues posed by human activity on our planet, ESA’s new ‘Clean Space’ initiative aims to address the same issues for its missions, making them greener by using more eco-friendly materials and finding ways to cut down levels of space debris.

Last month ESA and Eurospace organized the Clean Space Eco-design and Green Technologies Workshop 2012 held in the Netherlands. Clean Space is a major objective of Agenda 2015, the Agency’s upcoming action plan. The aim was outlined by ESA Director General Jean-Jacques Dordain: “If we are convinced that space infrastructure will become more and more essential, then we must transmit the space environment to future generations as we found it, that is, pristine.”

The workshop looked at all aspects of space missions, their total environment impact, from concept development to end of life. The impact of regulations regarding substances such as hydrazine, which is used widely as a propellant in space programs and the development of Green Propulsion with propellants that have a reduced toxicity. Environmental friendliness and sustainability often mean increased efficiency, which ESA hopes will give the industry a competitive advantage, so they are looking at technologies which will consume less energy and produce less waste, therefore cutting costs.

Finally they looked at debris mitigation to minimize the impact to the space environment as well as the debris footprint on Earth using controlled and uncontrolled re-entry events and passive de-orbiting systems along with active de-orbiting and re-orbiting systems. They are even considering tethers or sails to help drag abandoned satellites out of low orbit within 25 years. New ‘design for demise’ concepts hope to prevent chunks of satellites surviving re-entry and hitting the ground intact. Active removal of existing debris is also needed, including robotic missions to repair or de-orbit satellites.

6,000 satellites have been launched during the Space Age; less than 1000 of these are still in operation. The rest are derelict and liable to fragment as leftover fuel or batteries explode. Traveling at around 7.5 km/s, a 2 cm screw has a ‘lethal diameter’ sufficient to take out a satellite. Taking the recent loss of the Envisat satellite as an example, this satellite now poses a considerable threat as space junk. An analysis of space debris at Envisat’s orbit suggests there is a 15% to 30% chance of collision with another piece of junk during the 150 years it is thought Envisat could remain in orbit. The satellite’s complexity and size means even a small piece of debris could cause a “fragmentation event” producing its own population of space garbage. Envisat is also too big to be allowed to drift back into the Earth’s atmosphere. The choices seem to be to raise the satellite to a higher, unused orbit, or guide it back in over the Pacific Ocean.

As ESA Director General Jean-Jacques Dordain says “We will not succeed alone; we will need everyone’s help. The entire space sector has to be with us.”

Find out more about ESA’s Clean Space initiative here

June 26, 2012December 23, 2015 by Nancy Atkinson

Awesome Map of Space Agencies Around the World

When you think of space agencies around the world, what comes to mind? Probably NASA, ESA, ISRO and JAXA are the acronyms you know; then there’s the Russian Federal Space Agency, the Canadian Space Agency, and the China National Space Agency. But did you know there are dozens of countries with space agencies, with nearly 200 space agencies and centers around the world? Blogger Heather Archuletta has put together a map and list of all the space agencies on the planet, including countries you may not have realized had a space agency such as Argentina, Bulgaria, Pakistan Morocco, and more. The list includes links to all the space agency’s websites and a link to an interactive Google Map. The immediate thought that came to mind, which Heather shared on Twitter was, ROAD TRIP!

For any space nerd, that would be the ultimate global trek, to visit every space agency in the world. With all the NASA and Russian centers and all the various countries in ESA, your trip would include 198 locations around our planet!

Heather is known for her Pillownaut blog which originally detailed her time participating in NASA bedrest studies to simulate long duration spaceflight. The space agency map was a new project, born from a conversation with a friend.

“Overall, I created it to be a tracking tool, and to show how huge the space industry has become,” Heather told Universe Today. “Many people think of the space game as being the US, Russia and a handful of Europeans… but truly, lifestyle in many countries is dependent upon the use of space, even if it’s just as simple as remote sensing or collaborative satellites.”

Heather noted that the map includes one site in India that is not operational yet, but built.

But consider how many jobs around the world have been created because of space exploration… and these jobs employ some of the best and brightest minds in forward-thinking, global-enriching ways. And even more, there’s now the burgeoning private space industry that is employing even more people with jobs that focus on the future.

Check out http://pillownaut.com/spacemap/spacemap.html and plan your space-nerd road trip today!

June 21, 2012December 23, 2015 by Jenny Winder

Euclid and the Geometry of the Dark Universe

Artist’s impression of Euclid Credit: ESA/C. Carreau

Euclid, an exciting new mission to map the geometry, distribution and evolution of dark energy and dark matter has just been formally adopted by ESA as part of their Cosmic Vision 2015-2025 progamme. Named after Euclid of Alexandria, the “Father of Geometry”, it will accurately measure the accelerated expansion of the Universe, bringing together one of the largest collaborations of astronomers, engineers and scientists in an attempt to answer one of the most important questions in cosmology: why is the expansion of the Universe accelerating, instead of slowing down due to the gravitational attraction of all the matter it contains?

In 2007 the Hubble Space Telescope produced a 3D map of dark matter that covered just over 2 square degrees of sky, while in March this year the Baryon Oscillation Spectroscopic Survey (BOSS) measured the precise distance to just over a quarter of a million galaxies. Working in the visible and near-infrared wavelengths, Euclid will precisely measure around two billion galaxies and galaxy clusters in 3 dimensions in a wide extragalactic survey covering 15,000 square degrees (over a third of the sky) plus a deep survey out to redshifts of ~2, covering an area of 40 square degrees, the 3-D galaxy maps produced will trace dark energy’s influence over 10 billion years of cosmic history, covering the period when dark energy accelerated the expansion of the Universe.

The mission was selected last October but now that it has been formally adopted by ESA, invitations to tender will be released, with Astrium and Thales Alenia Space, Europe’s two main space companies expected to bid. Hoping to launch in 2020, Euclid will involve contributions from 11 European space agencies as well as NASA while nearly 1,000 scientists from 100 institutes form the Euclid Consortium building the instruments and participating in the scientific harvest of the mission. It is expected to cost around 800m euros ($1,000m £640m) to build, equip, launch and operate over its nominal 6 year mission lifetime, where it will orbit the second Sun-Earth Lagrange point (L2 in the image below) It will have a mass of around 2100 kg, and measure about 4.5 metres tall by 3.1 metres. It will carry a 1.2 m Korsch telescope, a near infrared camera/spectrometer and one of the largest optical digital cameras ever flown in space.

Dark matter represents 20% of the universe and dark energy 76%. Euclid will use two techniques to map the dark matter and measure dark energy. Weak gravitational lensing measures the distortions of light from distant galaxies due to the mass of dark matter, this requires extremely high image quality to suppress or calibrate-out image distortions in order to measure the true distortions by gravity. Euclid’s camera will produce images 100 times larger than those produced by Hubble, minimizing the need to stitch images together. Baryonic acoustic oscillations, wiggle patterns, imprinted in the clustering of galaxies, will provide a standard ruler to measure dark energy and the expansion in the Universe. This involves the determination of the redshifts of galaxies to better than 0.1%. It is also hoped that later in the mission, supernovas may be used as markers to measure the expansion rate of the Universe.

Find out more about Euclid and other Cosmic Vision missions at ESA Science

Lead image caption: Artist’s-impression-of-Euclid-Credit-ESA-C.-Carreau

Second image caption: Sun Earth Lagrange Points Credit: Xander89 via Wikimedia Commons

June 18, 2012December 23, 2015 by Jason Major

Milky Way to Concordia Base… Come In, Concordia Base…

This stunning photo of the Milky Way was captured from what may be the coldest and most isolated research facility on Earth: the French-Italian Concordia Base station, located at 3,200 meters (nearly 10,500 feet) altitude on the Antarctic plateau, 1,670 km (1,037 miles) from the geographic south pole.

Taken by Dr. Alexander Kumar, a doctor, researcher and photographer who’s been living at the Base since January, the image shows the full beauty of the sky above the southern continent — a sky that doesn’t see the Sun from May to August.

During the winter months no transportation can be made to or from Concordia Base — no deliveries or evacuations, not for any reason. The team there is truly alone, very much like future space explorers will one day be. This isolation is one reason that Concordia is used by ESA for research for missions to Mars.

Of course, taking photos outside is no easy task. Temperatures outside the Base in winter can drop down to -70ºC (-100ºF)!

Still, despite the isolation, darkness and cold, Dr. Kumar finds inspiration in his surroundings.

“The dark may cause fear, but if you take the time to adapt and look within it, you never know what you may find – at the bottom of the ocean, in the night sky, or under your bed in the middle of the night,” writes Kumar on the Concordia blog. “If you don’t overcome your fear of the ‘unknown’ and ‘monsters’, you will never see marvellous secrets hidden in the dark.

“I hope this photo inspires you too for the days, weeks and months ahead. In terms of the space exploration we are only beginning. We have to continue pushing out into the great beyond.”

Image credits: ESA/IPEV/PNRA – A. Kumar

June 11, 2012December 23, 2015 by Jason Major

Lightning From Space!

Photo of Earthly lightning seen from orbit by ESA astronaut Andre Kuipers

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Here’s an amazing shot of a flash of lightning within storm clouds over west Africa, captured from orbit by ESA astronaut André Kuipers aboard the ISS.

Lightning is a common sight from Space Station, creating a constant light show for the astronaut and cosmonaut crew members. On average, lightning strikes the ground somewhere on Earth 100 times each second, and there are 5 to 10 times as many cloud-to-cloud flashes as there are ground strikes. That adds up to about 40 to 80 million flashes of lightning every day around the world! Considering that the ISS orbits Earth 16 times a day — and from quite a high viewpoint — it stands to reason that lightning is spotted quite often.

So although it may not be rare, lightning still makes for dramatic photos — especially to those of us here on the ground!

For more information on André and his ongoing long-duration PromISSe mission, visit the ESA site here.

Image credit: ESA/NASA