Satellite images suggest dramatic rearrangements of sediments
Scientists think they see evidence of two huge tsunamis having once swept across the surface of Mars.
They point to satellite data suggesting a major redistribution of sediments over a large region at the edge of the Red Planet's northern lowlands.
The US-led team argues that asteroid or comet strikes into an ocean of water could have triggered the giant waves.
Such events could only have occurred more than three billion years ago when the planet was wetter and warmer.
Today, Mars is dry and cold, and any impact would merely dig out a dusty hole.
But researchers have long speculated that the low, flat terrain in Mars' northern hemisphere could have hosted an ocean if the climate conditions were just right.
The nagging doubt with this theory has been the absence of an identifiable shoreline - something the new study could now help explain.
The proposed tsunamis may have disguised the shoreline of an ancient ocean
If tsunamis regularly inundated the "land", dumping sediments and scouring new flow channels, they could over time have disguised what otherwise would have been an obvious "coast".
"For more than a quarter century, failure to identify shoreline features, consistently distributed along a constant elevation, has been regarded as inconsistent with the hypothesis that a vast ocean existed on Mars approximately 3.4 billion years ago," said Alexis Palmero Rodriguez from the Planetary Science Institute in Tuscon, Arizona.
"Our discovery offers a simple solution to this problem: widespread tsunami deposits distributed within a wide range of elevations likely characterise the shorelines of early Martian oceans."
Dr Rodriguez and colleagues' tsunami findings are due to appear on Thursday in the Nature journal Scientific Reports. Their work centres on two connected regions of Mars, known as Chryse Planitia and Arabia Terra.
The team interprets the sediments observed by satellite to betray the action of two ancient mega-tsunamis.
Did early Mars have a vast northern ocean?
The older event is perhaps easier to understand in an Earth context, where energetic waves can pick up and carry large boulders and other material and dump them at a higher elevation. The water, as it turns back, to run downhill, then cuts new channels. Dr Rodriguez's group points to such evidence.
But the scientists go on to describe the traces of a second, younger event. This is calculated to have occurred a few million years later, when the climate had cooled significantly. In this case, the tsunami wave froze as it propagated across the land surface, depositing "lobes" of sediment but producing no backwash channels.
On Earth, the frozen floes capping a sea or a lake can sometimes be pushed ashore by a storm surge. It is an unusual phenomenon but would be analogous to what is being suggested - albeit on a much larger scale - for Mars .
Having lost some currency, the idea of an ocean on Mars is gaining popularity again.
Investigations by Nasa's Curiosity rover at Gale Crater have revealed that the deep bowl likely contained persistent lakes in the past.
Such water, it is argued, could only have been maintained if there was a robust hydrological system on Mars, cycling moisture between a large sea somewhere on the planet, its atmosphere and its land surface.
Why school management matters even more than we thought
Good management in schools has a stronger effect than class sizes or quality teaching, according to new international research
The only thing more painful than teaching a Friday afternoon maths class to restless teenagers could be subjecting teachers to 'learnings' in management gobbledygook from a pimply consultant, barely older than the sixth formers who've just finished A-levels.
But hot air aside, better management in schools really can improve life for pupils, parents and teachers. And this country is doing much better than is often realised. Basic techniques of modern management that have become standard in leading organisations in other parts of the economy are more widespread in England than elsewhere in the world. These practices include rigorous collection of data on lessons, systematic feedback and supporting staff that struggle while rewarding and promoting great teachers.
Over the past decade, we have been doing research measuring management quality around the world. Most recently, we have looked at secondary schools in England and seven other countries: Brazil, Canada, Germany, India, Italy, Sweden and the United States. After more than 1,800 interviews with headteachers, some surprising results are emerging.
First, our measures of management quality suggest that good practices really matter for school performance. Improving the management quality of a school from the bottom 1% to the top 10% is linked with a 18% increase in GCSE scores and a 3% increase in 'contextual value added' – the improvement that children make in schools.
This is a much stronger effect than class size, teacher quality or competition. What's more, the powerful correlation between the management score and pupil performance is not just here but in every country we study. We can never rule out there is something else we haven't measured, but this link remains after taking account of a host of other factors.
One finding we were not expecting was that schools in England actually come out top in global comparisons of school management quality. Our schools seem to be much better at ensuring that the right mechanisms and incentives are in place to identify, develop, promote and retain good teachers than schools in other countries. Our interviews turned up many great examples of standardising high quality instruction through cross-curriculum, accessible lesson plans and mixing of scheduled and random class observations to ensure quality across classrooms.
Part of the reason for this could be major reforms in the last 20 years. There is a lot more focus on contextual value added rather than just crude measures of exam results. London Challenge encouraged the sharing of better practices across different schools and is probably a reason for the remarkable improvement in London's performance in the last decade.
But why are some schools better managed than others? It seems that more autonomous schools do better than regular schools across all countries. In England, for example, this would be academies, foundation and voluntary-aided schools; and in the United States, it would be charter and magnet schools. And this is not because autonomous schools are private schools that can cherry-pick their intake. In terms of management, autonomous state schools outperform private schools as well as regular state schools.
Indeed, the difference between autonomous state schools and other types of schools does not seem to reflect differences in composition of pupils, in school structure, location or in the obvious characteristics of head teachers such as gender or tenure. Governance and leadership are the answer.
If there is strong accountability to the local governing body, this is a great marker of excellent management. What's more, head teachers who have established a coherent long-term strategy and communicated it effectively to their staff and the wider school community unlock other beneficial managerial practices as well.
These findings suggest that reforms to education in England over the last 20 years in terms of decentralisation and driving up standards have not been as crazy as they sometimes have seemed. But they also suggest a strong note of caution. Autonomy is valuable but it is not enough by itself. The talents of teachers, school leaders and strong accountability to local governors are also needed to get management quality up from average to excellent.
We often beat ourselves up as a nation over our schools and there certainly are enormous challenges. But maybe things are not as dark as they sometimes seem.
The study can be found online at here. To see more results of the survey, download data and benchmark your school go towww.worldmanagementsurvey.org.
New Intel India Initiative Seeks to Infuse Technology in Education
In an effort to contribute further to the "Digital India" initiative, chip-making giant Intel India on Friday launched an initiative to strengthen the use of technology in the country's education ecosystem.
At an event jointly organised by Intel and the PHD Chamber of Commerce and Industry here, the company said it is collaborating with leading device manufacturers, education digital content and publishers and education solution providers to build end-to-end solutions that promote the use of technology in India's education sector.
"The initiative to create a comprehensive ecosystem is an endeavour to establish an accessible digital infrastructure that enables affordable solutions," said Debjani Ghosh, managing director of Intel South Asia, in a statement.
As part of this collaboration, Intel has made available its "Intel Pentium Processor A1020" to leading device manufacturer partners.
The processor delivers power savings and is optimal for devices designed for running education applications in semi-urban and rural India.
Device manufacturers such as Acer, HP, Dell, Lenovo, Micromax, Datamini and iBall will continue to provide a spectrum of Intel architecture-based devices, the company informed.
Intel will help deploy management solutions for schools, classrooms, content and learning and also manage student information systems.