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New Horizons probe eyes Pluto for historic encounter

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By Jonathan Amos

Science correspondent, BBC News

When it gets to Pluto, the New Horizons probe will have a packed schedule of observations

A Nasa probe is to start photographing the icy world of Pluto, to prepare itself for a historic encounter in July.

The New Horizons spacecraft has travelled 5bn km (3bn miles) over nine years to get near the dwarf planet.

And with 200m km still to go, its images of Pluto will show only a speck of light against the stars.

But the data will be critical in helping to align the probe properly for what will be just a fleeting fly-by.

Pluto will be photographed repeatedly during the approach, to determine the probe’s position relative to the dwarf planet, explained Mark Holdridge, from the Johns Hopkins University’s Applied Physics Laboratory (JHUAPL) in Baltimore.

“We then perform a number of correction manoeuvres to realign our trajectory with the reference trajectory, thus ensuring we hit our aim point to travel through the Pluto system,” he said.

Any initial correction is likely to be made in March.

The Pluto system has five known moons. Others may be discovered in the coming months

When New Horizons arrives at Pluto it will be moving so fast – at almost 14km/s – that going into orbit around the distant world is impossible; it must barrel straight through instead.

One complication is that the seven different instruments aboard the spacecraft need to work at different distances to get their data, and so the team has constructed a very elaborate observation schedule for them all.

But what this means is that very precise timing will be required to make sure the flyby runs smoothly.

The closest approach to Pluto is set for around 11:50 GMT on 14 July – at a miss distance of roughly 13,695km from the surface.

Mission planners want the exact timings nailed to within 100 seconds. New Horizons will know then where and when to point the instruments.

Dwarf Planet Pluto – Demoted but undiminished

Synthetic view Hubble’s best is a synthetic composite of multiple views. What are those shapes?

  • Discovered by Clyde Tombaugh on 18 February 1930
  • It is named after the Roman god of the underworld
  • An average of 5.9bn km from Sun and orbits every 248 years
  • Measuring its diameter is difficult but roughly 2,300km
  • It has a thin nitrogen atmosphere that comes and goes

 

The Pluto mission is being billed as the last great encounter in planetary exploration.

For people who grew up with the idea that there were “nine planets”, this is the moment they get to complete the set.

Robotic probes have been to all the others, even the distant Uranus and Neptune. Pluto is the last of the “classical nine” to receive a visit.

Of course, this 2,300km-wide ice-covered rock was demoted in 2006 to the status of mere “dwarf planet”, but scientists say that should not dull our enthusiasm.

The dwarfs are the most numerous planetary class in the Solar System, and Nasa’s New Horizons probe is one of the first opportunities to study an example up close.

The first set of navigation pictures may not be anything special, but by May, the probe will be returning views of Pluto that are better than anything from Hubble. Come July, the view should be spectacular, said Andy Cheng, the principal investigator on the probe’s main camera, which is called LORRI.

As Rebecca Morelle reports, even the Hubble Space Telescope could only capture blurry images of Pluto
“The most recent surprise we had was with the Rosetta mission. Hubble had made a ‘shape model’ of Comet 67P but no-one expected it to look like a rubber duckie,” he told BBC News. “I am more than hopeful that we will get similar surprises with New Horizons – it’s what we should expect.”

Those surprises could include yet more moons (five are currently known) and possibly even rings like those seen around some of the bigger planets.

Pluto is currently 5bn km from Earth. It has taken New Horizons more than nine years to get to the dwarf’s doorstep.

Once the flyby is complete, the probe will be targeted at an even more distant object in the Kuiper Belt – the name given to the icy domain beyond the main planets. Scientists think this region of space, and beyond, may contain many thousands of Pluto-like objects. Some even speculate there are far-flung worlds that rival Mars and Earth in size.

The first optical navigation images should be back on Earth by Tuesday at the latest. They will show Pluto with its largest moon, Charon.

The clip below is an interesting look at humanities probing of the stars. From the BBC series Explorations

 

Mystery Mars haze baffles scientists

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Mystery Mars haze baffles scientists

By Rebecca Morelle
Science Correspondent, BBC News

The plume appeared twice in 2012, and stretched for 1,000km

A mysterious haze high above Mars has left scientists scratching their heads.

The vast plume was initially spotted by amateur astronomers in 2012, and appeared twice before vanishing.

Scientists have now analysed the images and say that say the formation, stretching for more than 1,000km, is larger than any seen before.

Writing in the journal Nature, the researchers believe the plume could be a large cloud or an exceptionally bright aurora.

However, they are unsure how these could have formed in the thin upper reaches of the Martian atmosphere.

“It raises more questions than answers,” said Antonio Garcia Munoz, a planetary scientist from the European Space Agency.

Around the world, a network of amateur astronomers keep their telescopes trained on the Red Planet.

They first spotted the strange plume in March 2012 above Mars’ southern hemisphere.

Damian Peach was one of the first stargazers to capture images of the phenomenon.

He told BBC News: “I noticed this projection sticking out of the side of the planet. To begin with, I thought there was a problem with the telescope or camera.

“But as I checked more of the images, I realised it was a real feature – and it was quite a surprise.”

Damian Peach was one of the first astronomers to image the plume

The vast, bright haze lasted for about 10 days. A month later, it reappeared for the same length of time. But it has not been seen since.

An international team of scientists has now confirmed the finding, but they are struggling to find an explanation.

One theory is that the plume is a cloud of carbon dioxide or water particles.

“We know there are clouds on Mars, but clouds, up to this point, have been observed up to an altitude of 100km,” Dr Garcia Munoz said.

“And we are reporting a plume at 200km, so it is significantly different. At 200km, we shouldn’t see any clouds, the atmosphere is too thin – so the fact we see it for 20 days in total is quite surprising.”

Another explanation is that this is a Martian version of the northern or southern lights.

Dr Garcia Munoz explained: “We know in this region on Mars, there have been auroras reported before. But the intensities we are reporting are much much higher than any auroras seen before on Mars or on Earth.

“It would be 1,000 times stronger than the strongest aurora, and it is difficult to come to terms that Mars has such an intense aurora.”

If either of these theories are right, he said, it would mean our understanding of Mars’ upper atmosphere is wrong.

He hopes that by publishing the paper, other scientists might also come up with explanations.

If they cannot, astronomers will have to wait for the plumes to return.

Close-up observations from telescopes or the spacecraft that are currently in orbit around the Red Planet could help to solve this Martian mystery.

Earth’s biodiversity is helping scientist to design vehicles that will travel through space and land on Mars and other planets. It’s called ‘bio-inspiration’ as this video clip shows.


Brazil Amazon: Drone to scan for ancient Amazonia

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Brazil Amazon: Drone to scan for ancient Amazonia
By Jonathan Amos
BBC Science Correspondent, San Jose

The drone to be used in the project has a wingspan of about 3m

Scientists are to scan the Amazon forest in Brazil to look for evidence of occupation by ancient civilisations.

A drone will be sent up with a laser instrument to peer through the canopy for earthworks that were constructed thousands of years ago.

The UK-led project is trying to determine how big these communities were, and to what degree they altered the landscape.

The data is likely to inform policies on sustainable forest use today.

Researchers announced the initiative at the annual meeting of the American Association for the Advancement of Science in San Jose.

It has just won a 1.7m-euro (£1.25m; $1.9m) grant from the European Research Council.

The key quest is to try to understand the scale and activities of populations living in the late pre-Columbian period (the last 3,000 years before the Europeans arrived in the 1490s).

‘Cultural parkland’
The international team will endeavour to find more geoglyphs, which are large geometric patterns left in the ground.

More than 450 of these are known in places where the forest has been cleared.

No-one is really quite sure what these earthen circles, squares and lines represent. Perhaps, they were ceremonial centres. But what is certain is that they are evidence of collective behaviour.

“It’s a hot debate right now in New World archaeology,” said Dr Jose Iriarte from Exeter University, UK.

“While some researchers think that Amazonia was inhabited by small bands of hunter-gatherers and shifting cultivators who had a minimal impact on the environment, and that the forest we see today is pristine and untouched for thousands of years – mounting evidence is showing this may not be the case.

“This evidence suggests that Amazonia may have been inhabited by large, numerous, complex and hierarchical societies that had a major impact on the environment; what we call the ‘cultural parkland hypothesis’,” he told BBC News.

The Mysterious Amazon © SMG

The drone to be used in the project has a wingspan of about 3m
Dr Iriarte’s project will fly its robotic plane across sample areas of forest.

This vehicle’s lidar instrument should reveal how many more geoglyphs remain hidden beneath still-canopied regions of Amazonia.

While some of the light from the lidar scatters back off the leaves, some is able to penetrate to the ground.

A smart algorithm can then be used to separate the two signals, digitally removing the trees to expose anything unusual beneath.

If candidate geoglyphs are confirmed in follow-up inspections, scientists would then move in to characterise signature changes that have been left in the soils and vegetation by the ancient inhabitants.

These “fingerprints” could then be searched for in satellite images, enabling a much broader swathe of Amazonia to be probed than is possible with just a small unmanned aerial vehicle. The arguments over the scale of occupation and its impacts should then be settled.

In normal airborne imagery only the tops of the trees are visible

The lidar makes a map of the canopy in digital form…

…which can then be removed to leave only that signal of the laser that made it through to the ground

The project is a partnership between agencies and institutions in Europe and, of course, in Brazil.

Mysterious geoglyphs

The expectation is that lessons learned will feed into policies for the management and sustainable use of the Amazon and its resources.

Dr Iriarte said it was not possible to gauge properly what future changes would be acceptable unless there was a fuller understanding of how the forest had been altered in the past.

“We want to see what is the human footprint in the forest and then inform policy, because it may be the case that the very biodiversity that we want to preserve is the result of the past historical manipulation of this forest,” he explained.

Video clip of the amazing amazon.

 

Meteorite is ‘hard drive’ from space

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Meteorite is ‘hard drive’ from space

By Simon Redfern
BBC Science writer

The Esquel meteorite consists of gem-quality crystals embedded in metal.

Researchers have decoded ancient recordings from fragments of an asteroid dating back billions of years to the start of the Solar System.

They found tiny “space magnets” in meteorites which retain a memory of the birth and death of the asteroid’s core.

Like the data recorded on the surface of a computer hard drive, the magnetic signals written in the space rock reveal how Earth’s own metallic core and magnetic field may one day die.

The work appears in Nature journal.

Using a giant X-ray microscope, called a synchrotron, the team was able to read the signals that formed more than four-and-a-half billion years ago, soon after the birth of the Solar System.

The meteorites are pieces of a parent asteroid that originally came from asteroid belt, between Mars and Jupiter.

They represents the left-over fragments of a planet that failed to form. The magnetic recording within it traps a signal of the precise moments when an iron-rich core formed in the asteroid as well as when it froze, killing its magnetic field.

The new picture of metallic core solidification in the asteroid provide clues about the magnetic field and iron-rich core of Earth.

Core values

“Ideas about how the Earth’s core evolved through [our planet’s] history are really changing at the moment,” lead researcher Dr Richard Harrison, from the University of Cambridge, told BBC News.

“We believe that Earth’s magnetic field is linked to core solidification. Earth’s solid inner core may have started to form at very interesting time in terms of the evolution of life on Earth.

“By studying an asteroid we get to see this in fast forward. We can see the start of core solidification in the magnetic records as well as its end, and start to think about how these processes work on Earth.”

Magnetic field The Earth’s magnetic field will likely die off when the core completely freezes

The meteorites studied by the team originally fell to Earth in Argentina, and are composed of gem-quality crystals enclosed in a metallic matrix of iron and nickel.

Tiny particles, smaller than one thousandth the width of a human hair, trapped within the metal have retained the magnetic signature of the parent asteroid from its birth in the early Solar System.

“We’re taking ancient magnetic field measurements in nano-scale materials to the highest ever resolution in order to piece together the magnetic history of asteroids – it’s like a cosmic archaeological mission,” said Dr James Bryson, the paper’s lead author.

“Since asteroids are much smaller than Earth, they cooled much more quickly, so these processes occur on a shorter timescales, enabling us to study the whole process of core solidification.”

Don’t panic
Prof Wyn William, from the University of Edinburgh, who was not involved in the study, commented: “To be able to get a time stamp on these recordings, to get a cooling rate and the time of solidification, is fantastic. It’s a very nice piece of work.”

The key to the long-lived stability of the recording is the atomic-scale structure of the iron-nickel particles that grew slowly in the asteroid core and survived in the meteorites.

Scientists have attempted to synthesise the same iron-nickel structures in the lab, without widespread success so far. But their remarkable magnetic properties rival those of rare earth magnets, a key component of wind turbines and electric cars.

They may yet prove a route to making cheap, strong magnets without the need for scarce rare earth metals.

Making a final comment on the results, Dr Harrison said: “In our meteorites we’ve been able to capture both the beginning and end of core freezing, which will help us understand how these processes affected the Earth in the past and provide a possible glimpse of what might happen in the future.”

The Earth’s magnetic field will likely die off when the core completely freezes, and Earth will no longer be protected from the Sun’s radiation.

“There’s no need to panic” said Dr Harrison. “The core won’t completely freeze for billions of years, and chances are, the Sun will get us first.”


Mapping Earth’s Magnetic Fields

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By Jonathan Amos Science correspondent, BBC News

A field snapshot in June. Reds are strong; blues are weak. The view is dominated by the core contribution

Europe’s Swarm space mission has begun making maps of Earth’s magnetic field. Data just released shows how the field generated in the planet’s liquid outer core varies in strength over the course of a few months. Swarm’s early assessment appears to support the prevailing view that this magnetic cloak in general is weakening. Many experts believe it heralds a flip in the poles, where north becomes south and vice versa, although it would take thousands of years to complete. The European Space Agency’s Swarm mission was launched last November. It comprises three satellites that are equipped with a variety of instruments – the key ones being state-of-the-art magnetometers that measure field strength and direction. They fly in a configuration that offsets one platform from the other two. The intention is that this should provide a three-dimensional view of the field, and make it easier to tease apart its various components. In the release this week from Esa, we get a view that is dominated by the contribution (95%) from the core. But eventually, Swarm will have the sensitivity to describe magnetism from other, more subtle sources, including that generated by the movement of our salt-water oceans.

Change in the field since January. Reds are a strengthening; blues are a weakening

The maps on this page use the magnetic unit of a nanoTesla. Earth’s field typically has a full strength of some 50,000nT. The maps illustrate a snapshot (in June) and the change that occurs through time (January to June). In the latter, field strength is seen to drop over the western hemisphere but rise in other areas, such as the southern Indian Ocean. Earth’s magnetic field is worthy of study because it is the vital shield that protects the planet from all the charged particles streaming off the Sun. Without it, those particles would strip away the atmosphere, just as they have done at Mars. Investigating the magnetic field also has direct practical benefits, such as improving the reliability of satellite navigation systems which can be affected by magnetic and electrical conditions high in the atmosphere. “I started my career in magnetometry and the accuracy we had then in the laboratories was less than what we can fly in space now,” explained Prof Volker Liebig, the director of Earth observation at Esa. “So what we have on Swarm is fantastic, but we need long time series to understand fully the Earth’s magnetic field, and we will get that from this mission,” he told BBC News.

The Swarm fly high above the Earth in a configuration that offsets one satellite from a pair of spacecraft

Has the Earth already been mapped by Aliens? Do Aliens even exist? Some people say yes, others no. Here’s an interesting perspective from one of NASA’s astronauts including Story Musgrave and SETI’s Seth Shostack. http://youtu.be/MBK6eHWbwNc

 

Prehistoric North Sea Atlantis hit by 5 metre tsunami

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By Paul Rincon
Science editor, BBC News website

A prehistoric “Atlantis” in the North Sea may have been abandoned after being hit by a 5m tsunami 8,200 years ago.

The wave was generated by a catastrophic subsea landslide off the coast of Norway.

Analysis suggests the tsunami over-ran Doggerland, a low-lying landmass that has since vanished beneath the waves.

“It was abandoned by Mesolithic tribes about 8,000 years ago, which is when the Storegga slide happened,” said Dr Jon Hill from Imperial College London.

The wave could have wiped out the last people to occupy this island.

The research has been submitted to the journal Ocean Modelling and is being presented at the European Geosciences Union General Assembly in Vienna this week.

Dr Hill and his Imperial-based colleagues Gareth Collins, Alexandros Avdis, Stephan Kramer and Matthew Piggott used computer simulations to explore the likely effects of the Norwegian landslide.

He told BBC News: “We were the first ever group to model the Storegga tsunami with Doggerland in place. Previous studies have used the modern bathymetry (ocean depth).”

As such, the study gives the most detailed insight yet into the likely impacts of the huge landslip and its associated tsunami wave on this lost landmass.


During the last Ice Age, sea levels were much lower; at its maximum extent Doggerland connected Britain to mainland Europe.

It was possible for human hunters to walk from what is now northern Germany across to East Anglia.

But from 20,000 years ago, sea levels began to rise, gradually flooding the vast landscape.

By around 10,000 years ago, the area would still have been one of the richest areas for hunting, fishing and fowling (bird catching) in Europe.

A large freshwater basin occupied the centre of Doggerland, fed by the River Thames from the west and by the Rhine in the east. Its lagoons, marshes and mudflats would have been a haven for wildlife.

“In Mesolithic times, this was paradise,” explained Bernhard Weninger, from the University of Cologne in Germany, who was not involved with the present study.

But 2,000 years later, Doggerland had become a low-lying, marshy island covering an area about the size of Wales.

The North Sea has given up wonderful prehistoric finds, like these bone points now kept at the National Museum of Antiquities in Leiden, The Netherlands

This shaft-hole pick made from antler was found near Rotterdam in the Netherlands

The nets of North Sea fishing boats have pulled up a wealth of prehistoric bones belonging to the animals that once roamed this prehistoric “Garden of Eden”.

But the waters have also given up a smaller cache of ancient human remains and artefacts from which scientists have been able to obtain radiocarbon dates.

And they show that none of these relics of Mesolithic habitation on Doggerland occur later than the time of the tsunami.

The Storegga slide involved the collapse of some 3,000 cubic km of sediment.

“If you took that sediment and laid it over Scotland, it would cover it to a depth of 8m,” said Dr Hill.

Given that the majority of Doggerland was by this time less than 5m in height, it would have experienced widespread flooding.

These young Mesolithic women from Teviec, Brittany, were brutally murdered. As sea levels rose competition for resources may have intensified

“It is therefore plausible that the Storegga slide was indeed the cause of the abandonment of Doggerland in the Mesolithic,” the team writes in their Ocean Modelling paper.

Dr Hill told BBC News: “The impact on anyone who was living on Doggerland at the time would have been massive – comparable to the Japanese tsunami of 2011.”

But Bernhard Weninger suspects that Doggerland had already been vacated by the time of the Storegga slide.

“There may have been a few people coming with boats to fish, but I doubt it was continuously settled,” he explained.

“I think it was so wet by this time that the good days of Doggerland were already gone.”

Prof Vince Gaffney, an archaeologist at the University of Birmingham, said: “I think they (the researchers) are probably right, because the tsunami would have been a catastrophic event.”

But he stressed that the archaeological record was sparse, and explained that two axes from the Neolithic period (after Storegga) had been retrieved from the North Sea’s Brown Banks area.

It is possible these were dropped from a boat – accidentally or as a ritual offering – but it is also unclear precisely when Doggerland finally succumbed to the waves.

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