ESA Planck Telescope: Sky Survey changes date on early stars

Planck has mapped the delicate polarisation of the CMB across the entire sky

Scientists working on ESA's Planck satellite say the first stars in the Universe lit up later than was previously thought.

The team has made the most precise map of the "oldest light" in the cosmos.

Earlier observations of this radiation had suggested that the first generation of stars burst into life about 420 million years after the Big Bang.

The new Planck data now indicates they fired up around 560 million years after the Universe got going.

"This difference of 140 million years might not seem that significant in the context of the 13.8-billion-year history of the cosmos, but proportionately it's actually a very big change in our understanding of how certain key events progressed at the earliest epochs," said Prof George Efstathiou, one of the leaders of the Planck Science Collaboration.

Subtle signal
The assessment is based on studies of the "afterglow" of the Big Bang, the ancient light called the Cosmic Microwave Background (CMB), which still washes over the Earth today.

The European Space Agency's (ESA) Planck satellite mapped this "fossil" between 2009 and 2013.

It contains a wealth of information about early conditions in the Universe, and can even be used to work out its age, shape and do an inventory of its contents.

Scientists can also probe it for very subtle "distortions" that tell them about any interactions the CMB has had on its way to us.

Forging elements
One of these would have been imprinted when the infant cosmos underwent a major environmental change known as re-ionisation.

It is when the cooling neutral hydrogen gas that dominated the Universe in the aftermath of the Big Bang was then re-energised by the ignition of the first stars.

These hot giants would have burnt brilliant but brief lives, producing the very first heavy elements. But they would also have "fried" the neutral gas around them - ripping electrons off the hydrogen protons.

And it is the passage of the CMB through this maze of electrons and protons that would have resulted in it picking up a subtle polarisation.

Impression: The first stars would have been unwieldy behemoths that burnt brief but brilliant lives

The Planck team has now analysed this polarisation in fine detail and determined it to have been generated at 560 million years after the Big Bang.

The American satellite WMAP, which operated in the 2000s, made the previous best estimate for re-ionisation at 420 million years.

The problem with that number was that it sat at odds with Hubble Space Telescope observations of the early Universe.

Hubble could not find stars and galaxies in sufficient numbers to deliver the scale of environmental change at the time when WMAP suggested it was occurring.

Planck's new timing "effectively solves the conflict," commented Prof Richard McMahon from Cambridge University, UK.

"We had two groups of astronomers who were basically working on different sides of the problem. The Planck people came at it from the Big Bang side, while those of us who work on galaxies came at it from the 'now side'.

"It's like a bridge being built over a river. The two sides do now join where previously we had a gap," he told reporters.

That gap had prompted scientists to invoke complicated scenarios for how re-ionisation could have occurred, including the ideas that there were an even earlier population of giant stars or energetic black holes. Such solutions are no longer needed.

The finding is also good news for the next generation of observatories like the James Webb Space Telescope, which will have the power to see right through the epoch of re-ionisation.

SSTL TechDemoSat-1 on Fregat upper stage of Soyuz-2: Launch date 28th June

Surrey Satellite Technology Ltd (SSTL) is announcing the launch of TechDemoSat-1, an in-orbit technology demonstration mission for innovative UK spacecraft equipment and software, planned for 28th June 2014 by a Soyuz-2 launch vehicle with a Fregat upper stage from the Baikonur Cosmodrome in Kazakhstan.

TechDemoSat-1 is based on the SSTL-150 platform and is part-funded by a small grant from the UK's Technology Strategy Board, and SEEDA (South East England Development Agency).

The spacecraft will carry eight separate payloads from UK academia and industry, providing valuable in-orbit validation for new technologies.

Iain Gray, the Chief Executive of the Technology Strategy Board, said: "The UK is home to an expert space community and the Technology Strategy Board supports businesses with potential to be world leaders in this growing sector."

"Technology and data from space can help solve problems on the ground, in agriculture, healthcare, transport and many other areas of life."

"This mission is an exciting opportunity to flight test innovative technology in extreme conditions."

The payloads flying on TechDemoSat-1 are:

• MuREM, a flexible miniature radiation and effects monitor from Surrey Space Centre
• ChaPS, a prototype compact instrument to detect electrons and ions from the Mullard Space Science Laboratory
• HMRM, a lightweight, ultra-compact radiation monitor designed to measure total radiation dose, particle flux rate and identify electrons, protons and ions from Rutherford Appleton Laboratory and Imperial College
• LUCID, a device to measure characterisation of the energy, type, intensity and directionality of high energy particles from the Langton Star Centre
• Compact Modular Sounder system, a modular infrared remote sensing radiometer unit from Oxford University's Planetary Group and Rutherford Appleton Laboratory
• De-orbit sail from Cranfield University
• Cubesat ADCS, a 3-axes attitude determination and control subsystem from SSBV
• Sea State Payload, a device using an enhanced GPS receiver from SSTL and components from a Synthetic Aperture Radar from Airbus Defence and Space to monitor reflected signals to determine ocean roughness

Dr Matt Perkins, SSTL's CEO, commented "We are delighted to provide the platform that will carry innovative new British technologies into space, along with over 20 product developments for SSTL."

"We have worked closely with the payload providers for this mission and nothing would please us better than seeing these new technologies developed for the market as a result of the in-orbit demonstration opportunity they are being given on TechDemoSat-1."

The Launch and Early Operations phase (LEOP) and platform commissioning will be performed by SSTL from the Satellite Applications Catapult Operations Centre at Harwell.

Subsequently, the commissioning of the payloads will be performed by SSTL via its own Mission Control Centre in Guildford before handing over day-to-day operation of the payloads back to the Catapult. SSTL will continue to manage spacecraft level monitoring and operations for TechDemoSat-1 in Guildford.

New Research Re-Calculates date of Moon's Magnetic Dynamo by 160 million years

Mosaic of the near side of the moon as taken by the Clementine star trackers. 

The images were taken on March 15, 1994. 

Credit: NASA

A multi-disciplinary team of international researchers has found evidence to suggest the moon's dynamo persisted until at least 3.6 billion years ago.

In their paper published in the Proceedings of the National Academy of Sciences, the team says this pushes back the date for the dynamo approximately 160 million years.

Currently, the moon has no global magnetic field, but analysis of rocks brought back by Apollo astronauts showed that it did at one time. To create such a field, the moon would necessarily have had some churning in its interior—a dynamo.

Evidence of a dynamo inside the moon has led scientists to propose different theories as to how it might have come about.

Some scientists suggest it might have been due to an impact that knocked the internals loose and set them moving for a period of time.

Others theorise it might have been more likely due to differences in heat distribution during radioactive decay, prompting liquid shifting.

Clément Suavet

The lead author, Clément Suavet is currently assigned to the MIT Department of Earth, Atmospheric and Planetary Sciences (EAPS).

To gain a better understanding of the moon's dynamo and how it might have occurred, researchers have been working to more clearly define when it came about, how strong it was and how long it lasted.

To that end, researchers with this latest effort went back to the moon rocks that started the whole debate.

Using newer technology to analyse the rocks, they found that they had, on average, fields of 13–70 microtesla—the higher readings are on a par with that of Earth's magnetic field.

More importantly, they found that the rocks showed that a dynamo existed as far back as 3.6 billion years ago.

 Suavet says, 'This new finding shoots down the idea of the dynamo forming due to a large impact.'

That's because other research has shown that no impacts large enough to cause a dynamo have occurred since approximately 3.72 billion years ago—well before the age of the samples found but that still doesn't reveal the actual cause.

Though they can't prove it, the group suggests the dynamo mostly likely occurred due to interaction with Earth's gravity—likening it to a tug-of-war between the solid mantel and the liquid core, resulting in a constant internal churning.

More information: Persistence and origin of the lunar core dynamo, PNAS, Published online before print May 6, 2013, doi: 10.1073/pnas.1300341110

ESA ATV-4: Albert Einstein set to Launch June 2013

ESA's space freighter ATV Albert Einstein will be the heaviest spacecraft ever launched into space by an Ariane rocket when it lifts off to the International Space Station on 5 June.

Albert Einstein is the fourth in the five-vessel Automated Transfer Vehicle (ATV)-series of space cargo freighters and is undergoing final integration and cargo loading at Europe's Spaceport in Kourou.

It will launch on board an Ariane 5 ES launcher, delivering over 2500 kg of dry cargo to the International Space Station. It will also haul fuel, water, and oxygen to space, as well as carrying its own fuel to reboost the Station's orbit.

The total mass of ATV Albert Einstein with all its cargo is 20 235 kg, making this spacecraft the heaviest ever lofted into orbit by an Ariane rocket, beating the previous Ariane launch record by over 500 kg set last year by its predecessor ATV Edoardo Amaldi.

Most diverse cargo ever 
"ATV-4 is carrying the most diverse-ever cargo mix – around 1400 different items – ranging from food, spare parts, crew supplies and clothing to scientific experiments and other vital items," says Alberto Novelli, ATV-4 mission manager.

Alberto Novelli

"Launch is scheduled for 5 June on Ariane flight VA213, which would line us up for docking with the International Space Station on 15 June."

Teams from ESA, Arianespace and Astrium, the vessel's builder, have been working at Kourou on an intense pre-launch campaign that began the moment the two halves of ATV vessel arrived in French Guiana last September.

The spacecraft has been checked out, the two halves joined into one and fuelling is underway. ATV Albert Einstein will be hoisted to the top of its Ariane launcher in May.

Late-load cargo can be added just two weeks before launch, this year, around 620 kg of ‘last-minute’ items are expected to be shipped to the Space Station.

Charlotte Beskow

"Late loading offers flexible options to our partners to include critical items needed on the Space Station closer to the actual launch date" says Charlotte Beskow ESA's acting launch campaign manager in Kourou.

In parallel, the joint ESA/French space agency (CNES) flight control team at the ATV Control Centre in Toulouse, France has been doing intensive training and simulations for the mission's flight phases.

ESA's Rosetta: Date With Asteroid Lutetia

ESA's comet-chaser Rosetta is heading for a blind date with asteroid Lutetia. Rosetta does not yet know what Lutetia looks like but beautiful or otherwise the two will meet on 10 July.

Like many first dates, Rosetta will meet Lutetia on a Saturday night, flying to within 3200 km of the space rock.

Rosetta started taking navigational sightings of Lutetia at the end of May so that ground controllers can determine any course corrections required to achieve their intended flyby distance.

The close pass will allow around 2 hours of good imaging. The spacecraft will instantly begin beaming the data back to Earth and the first pictures will be released later that evening.

Rosetta flew by asteroid Steins in 2008 and other space missions have encountered a handful of asteroids. Each asteroid has proven to be an individual and Lutetia is expected to continue the trend.

For a start, no one knows what it looks like. Orbiting in the main belt of asteroids between Mars and Jupiter, it appears as a single point of light to ground telescopes. The continuous variation in its brightness makes it clear that Lutetia is rotating and has an uneven surface. These observations allow astronomers to estimate its shape and size, but their determinations all differ.

Initially it was thought that Lutetia is around 95 km in diameter but only mildly elliptical. A more recent estimate suggests 134 km, with a pronounced elongation. Rosetta will tell us for certain and will also investigate the composition of the asteroid, wherein lies another mystery.

By any measure, Lutetia is quite large. Planetary scientists believe that it is a primitive asteroid left on the shelf for billions of years because no planet consumed it as the Solar System formed. Indeed, most measurements appear to back this picture, making the asteroid out to be a 'C-type', which contains primitive compounds of carbon.

However, some measurements suggest that Lutetia is an 'M-type', which could mean there are metals in its surface. "If Lutetia is a metallic asteroid then we have found a real winner," says Rita Schulz, ESA Rosetta Project Scientist.

That is because although metallic asteroids do exist, they are thought to be fragments of the metallic core of larger asteroids that have since been shattered into pieces. If Lutetia is made of metal or even contains large amounts of metal, Dr Schulz says that the traditional asteroid classification scheme will need rethinking. "C-class asteroids should not have metals on their surfaces," she says.

Asteroid science stands to gain once this observational conundrum is resolved because Rosetta's data will provide a valuable collection of 'ground truths' that can be used to resolve conflicting ground-based observations not just for Lutetia but for other asteroids as well.

For 36 hours around the moment of closest approach, Rosetta will be in almost continuous contact with the ground. The only breaks will come as Earth rotates and engineers have to switch from one tracking station to another.

Good contact is essential because the uncertainties in the asteroid's position and shape may demand last minute fine-tuning to keep it centred in Rosetta's instruments during the flyby.

"The skeleton of the operation is in place, and we have the ability to update our plans at any time," says Andrea Accomazzo, ESA Rosetta Spacecraft Operations Manager.