wonder of 7 company

Tuesday, 29 September 2015

NASA's MAVEN Celebrates One Year at Mars

Artist Concept of NASA's Mars Atmosphere and Volatile Evolution (MAVEN)

This image shows an artist concept of NASA's Mars Atmosphere and Volatile Evolution (MAVEN) mission. Credit: NASA/Goddard Space Flight Center

NASA's Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft has been in orbit around Mars for one Earth year. MAVEN was launched to Mars on Nov. 18, 2013 from Cape Canaveral Air Force Station in Florida and successfully entered Mars' orbit on Sept. 21, 2014.

"The success of the mission so far is a direct result of the incredibly hard work of everybody who is working and has worked on MAVEN. This one year at Mars reflects the tremendous efforts over the preceding dozen years," said Bruce Jakosky, MAVEN's principal investigator from the University of Colorado's Laboratory for Atmospheric and Space Physics in Boulder.

Some of the highlights of the first action-packed year include:

- Performing the orbit insertion maneuver
- Surviving the encounter with Comet Siding Spring
- Commissioning the spacecraft
- Carrying out ten months of observations during MAVEN's primary mission
- Carrying out four deep-dip campaigns

"The team has done a fantastic job of adapting to spacecraft operations in the Martian environment," said Richard Burns, MAVEN project manager at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "All systems on MAVEN remain in excellent working condition."

MAVEN began its primary science mission on Nov. 16, 2014, and is the first spacecraft dedicated to understanding Mars' upper atmosphere. The goal of the mission is to determine the role that loss of atmospheric gas to space played in changing the Martian climate through time. MAVEN is studying the entire region from the top of the upper atmosphere all the way down to the lower atmosphere so that the connections between these regions can be understood.

"We still have two months to go in our primary mission, and then we begin our extended mission," Jakosky said. "We're obtaining an incredibly rich data set that is on track to answer the questions we originally posed for MAVEN and that will serve the planetary science community for a long time to come."

MAVEN's principal investigator is based at the University of Colorado's Laboratory for Atmospheric and Space Physics, Boulder. The university provided two science instruments and leads science operations, as well as education and public outreach, for the mission. NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the MAVEN project and provided two science instruments for the mission. Lockheed Martin built the spacecraft and is responsible for mission operations. The University of California at Berkeley's Space Sciences Laboratory also provided four science instruments for the mission. NASA's Jet Propulsion Laboratory in Pasadena, California, provides navigation and Deep Space Network support, as well as the Electra telecommunications relay hardware and operations.

For more information about MAVEN, visit:

www.nasa.gov/maven

Tom Mason
Laboratory for Atmospheric and Space Physics
University of Colorado, Boulder

Nancy Neal-Jones
NASA's Goddard Space Flight Center, Greenbelt, Md.

Nasa scientists find evidence of flowing water on Mars

Researchers say discovery of stains from summertime flows down cliffs and crater walls increases chance of finding life on red planet

Liquid water runs down canyons and crater walls over the summer months onMars, according to researchers who say the discovery raises the chances of being home to some form of life.

The trickles leave long, dark stains on the Martian terrain that can reach hundreds of metres downhill in the warmer months, before they dry up in the autumn as surface temperatures drop.

Images taken from the Mars orbit show cliffs, and the steep walls of valleys and craters, streaked with summertime flows that in the most active spots combine to form intricate fan-like patterns.

Scientists are unsure where the water comes from, but it may rise up from underground ice or salty aquifers, or condense out of the thin Martian atmosphere.

“There is liquid water today on the surface of Mars,” Michael Meyer, the lead scientist on Nasa’s Mars exploration programme, told the Guardian. “Because of this, we suspect that it is at least possible to have a habitable environment today.”

The water flows could point Nasa and other space agencies towards the most promising sites to find life on Mars, and to landing spots for future human missions where water can be collected from a natural supply.

“Mars is not the dry, arid planet that we thought of in the past,” said Nasa’s Jim Green. “Liquid water has been found on Mars.”

Nasa announce that there are watery flows on the surface of Mars during the red planet’s summer months.

Some of the earliest missions to Mars revealed a planet with a watery past. Pictures beamed back to Earth in the 1970s showed a surface crossed by dried-up rivers and plains once submerged beneath vast ancient lakes. Earlier this year, Nasa unveiled evidence of an ocean that might have covered half of the planet’s northern hemisphere in the distant past.

Dark narrow streaks called recurring slope lineae emanate out of the walls of Garni crater on Mars. Photograph: Nasa/AFP/Getty Images

But occasionally, Mars probes have found hints that the planet might still be wet. Nearly a decade ago, Nasa’s Mars Global Surveyor took pictures of what appeared to be water bursting through a gully wall and flowing around boulders and other rocky debris. In 2011, the high-resolution camera on Nasa’s Mars Reconnaissance Orbiter captured what looked like little streams flowing down crater walls from late spring to early autumn. Not wanting to assume too much, mission scientists named the flows “recurring slope lineae” or RSL.

Researchers have now turned to another instrument on board the Mars Reconnaissance Orbiter to analyse the chemistry of the mysterious RSL flows.Lujendra Ojha, of Georgia Institute of Technology in Atlanta, and his colleagues used a spectrometer on the MRO to look at infrared light reflected off steep rocky walls when the dark streaks had just begun to appear, and when they had grown to full length at the end of the Martian summer.

Writing in the journal Nature Geosciences, the team describes how it found infra-red signatures for hydrated salts when the dark flows were present, but none before they had grown. The hydrated salts – a mix of chlorates and perchlorates – are a smoking gun for the presence of water at all four sites inspected: the Hale, Palikir and Horowitz craters, and a large canyon called Coprates Chasma.

“These may be the best places to search for extant life near the surface of Mars,” said Alfred McEwen, a planetary geologist at the University of Arizona and senior author on the study. “While it would be very important to find evidence of ancient life, it would be difficult to understand the biology. Current life would be much more informative.”

The flows only appear when the surface of Mars rises above -23C. The water can run in such frigid conditions because the salts lower the freezing point of water, keeping it liquid far below 0C.

“The mystery has been, what is permitting this flow? Presumably water, but until now, there has been no spectral signature,” Meyer said. “From this, we conclude that the RSL are generated by water interacting with perchlorates, forming a brine that flows downhill.”

These channels, which are between 1 metre and 10 metres wide, are on a scarp in the Hellas impact basin. Photograph: Nasa/Reuters

John Bridges, a professor of planetary science at the University of Leicester, said the study was fascinating, but might throw up some fresh concerns for space agencies. The flows could be used to find water sources on Mars, making them prime spots to hunt for life, and to land future human missions. But agencies were required to do their utmost to avoid contaminating other planets with microbes from Earth, making wet areas the most difficult to visit. “This will give them lots to think about,” he said.

For now, researchers are focused on learning where the water comes from. Porous rocks under the Martian surface might hold frozen water that melts in the summer months and seeps up to the surface.

Another possibility is that highly concentrated saline aquifers are dotted around beneath the surface, not as pools of water, but as saturated volumes of gritty rock. These could cause flows in some areas, but cannot easily explain water seeping down from the top of crater walls.

A third possibility, and one favoured by McEwen, is that salts on the Martian surface absorb water from the atmosphere until they have enough to run downhill. The process, known as deliquescence, is seen in the Atacama desert, where the resulting damp patches are the only known place for microbes to live.

“It’s a fascinating piece of work,” Bridges said. “Our view of Mars is changing, and we’ll be discussing this for a long time to come.”

Monday, 28 September 2015

Shell has made a costly call to abandon Alaska

Kamal AhmedBusiness editor

Protestors against Shell's drilling in the Arctic — Image captionShell's exploration in the Arctic led to protests from environmentalists

It could have been Hillary Clinton's tweet that did it.

Just after the US government had given the go-ahead for Shell to restart its exploration in Alaska, the Democratic presidential candidate took to the social media site.

"The Arctic is a unique treasure," Mrs Clinton said on Twitter. "Given what we know now, it's not worth the risk of drilling."

Which seemed to ignore the fact that drilling has been taking place in the Arctic for decades - for example oil was first discovered in one of the main basins, Prudhoe Bay, in 1968.

The area is still producing around 250,000 barrels per day and is one of America's largest producing fields.

Shell knows that its every move in the Arctic is scrutinised commercially, politically and environmentally.

Quite rightly, of course, when it comes to exploration in one of the most environmentally sensitive areas in the world.

Surprise move

Shell's original position on the Arctic was that exploration of the vast area - much of it untapped - was important.

The oil major argued that demand for fossil fuels was increasing as the world developed, exploration had to continue despite the low oil price and that the Arctic had long been a source of oil and gas.

This morning's announcement that Shell was pulling out of the Chukchi Sea therefore comes as a surprise.

Particularly given it will cost Shell £2.6bn to execute the withdrawal.

And that the company has already spent the thick end of £5bn getting to this point.

Earlier this year, I interviewed Shell's chief executive Ben van Beurden - and he was certainly bullish on Alaska.

"The potential in the Arctic is very, very significant," he told me, saying that "the Arctic probably holds the largest yet to be discovered resource base".

Shell's investors were regular recipients of long and detailed presentations on the potential for the region.

So, what changed?

Certainly, the first findings from the Burger J exploration well 150 miles off the Alaskan coast were not promising.

Second, although President Barack Obama had given the necessary permissions for drilling to start again following the problems of rig fires in 2012, Mrs Clinton's tweet revealed that political risks were still substantial.

Mr van Beurden also has plenty of other issues weighing on his in-tray.

Not least the £55bn takeover of BG Group.

And the halving on the oil price over the past 18 months which has led to a rapid reduction in capital expenditure for all the oil majors.

Share prices have been under pressure, with Shell's dropping over 30% in the last 12 months.

Given that background, the Arctic appears to be one major project too far, for Shell's management as well as investors.

And, frankly, there are easier places to explore for oil and gas, technically and politically.

'High risk'

That was very much the opinion of Lord Browne, the former chief executive of BP who is now chairman of the oil and gas business, L1 Energy.

I spoke to him this morning.

"The Arctic is a very high risk place to explore, and even if you find something, a very expensive place to develop in," he told me.

"The last very big field is Prudhoe Bay, and it's been a very difficult place to find oil and gas.

"There'll be better places, more easy places, to go and explore."

But, with demand for fossil fuels expected to rise over the next decade as emerging market growth continues, Lord Browne says exploration in the area off Alaska could return.

"We should always keep an eye on it, just in case."

Martian salt streaks 'painted by liquid water'

By Jonathan Amos

Image captionDark streaks: Recurring slope lineae can be hundreds of metres long

Scientists think they can now tie dark streaks seen on the surface of Mars to periodic flows of liquid water.

Data from a Nasa satellite shows the features, which appear on slopes, to be associated with salt deposits.

Crucially, such salts could alter the freezing and vaporisation points of water in Mars's sparse air, keeping it in a fluid state long enough to move.

Lujendra Ojha and colleagues report the findings in the journal Nature Geoscience.

There are implications for the existence of life on the planet today, because any liquid water raises the possibility that microbes could also be present. And for future astronauts on Mars, the identification of water supplies near the surface would make it easier for them to "live off the land".

Researchers have long wondered whether liquid water might occasionally flow across the surface today.

Secret source

It is not a simple proposition, because the temperatures are usually well below zero Celsius and the atmospheric pressure is so low that any liquid H20 will rapidly boil.

But the observation over the past 15 years of gullies and surface streaks that appear to change with the seasons has heightened the speculation.

Dr Ojha has now presented new data from the US space agency's Mars Reconnaissance Orbiter that seems to solve the conundrum.

MRO has an instrument called Crism that can determine the chemistry of surface materials.

It has looked at four locations where dark streaks are seen to come and go during Martian summer months.

Crism finds these "recurring slope lineae" (RSL) to be covered with salts.

They are salts - magnesium perchlorate, chlorate and chloride - that can drop the freezing point of water by 80 degrees and its vaporisation rate by a factor of 10.

The combination allows briney water to stay stable long enough to trickle down hillsides and crater walls.

Quite where the water is coming from to make the streaks is still unclear, however. The locations studied by MRO are equatorial, and any stored water in this region of Mars, perhaps in the form of ice, is thought to exist only at great depth.

One possibility is that the salts actually pull the water out of the atmosphere. The Curiosity rover has found some strong pointers to this mechanism. But again, it is not known whether there is a sufficient supply in the air to facilitate a decent flow.

Another theory is that local aquifers are breaking up to the surface, but this does not really fit with streaks that appear from the tops of peaks.

It is conceivable that streaks are being formed from different sources in different parts of Mars.

Contamination question

Dr Joe Michalski is a Mars researcher at the Natural History Museum in London. He called the announcement an exciting development, especially because of its implications for the potential of microbes existing on the planet today.

"We know from the study of extremophiles on Earth that life can not only survive, but thrive in conditions that are hyper-arid, very saline or otherwise 'extreme' in comparison to what is habitable to a human. In fact, on Earth, wherever we find water, we find life. That is why the discovery of water on Mars over the last 20 years is so exciting."

An interesting consequence of the findings is that space agencies will now have some extra thinking to do about where they send future landers and rovers.

Current internationally-agreed rules state that missions should be wary of going to places on Mars where there is likely to be liquid water.

A UK space agency expert on Mars landing sites, Dr Peter Grindrod, told BBC News: "Planetary protection states that we can't go anywhere there is liquid water because we can't sterilise our spacecraft well enough to guarantee we won't contaminate these locations. So if an RSL is found within the landing zone of a probe, then you can't land there. That would be kind of ironic for Europe's forthcoming ExoMars rover because it's designed to look for life."

Jonathan.Amos-INTERNET@bbc.co.uk and follow me on Twitter:@BBCAmos

View comments4

wonder of 7 company

ABOUT

Tuesday, 29 September 2015

NASA's MAVEN Celebrates One Year at Mars

NASA's MAVEN Celebrates One Year at Mars

Nasa scientists find evidence of flowing water on Mars

Nasa scientists find evidence of flowing water on Mars

Monday, 28 September 2015

Shell has made a costly call to abandon Alaska

Shell has made a costly call to abandon Alaska

Surprise move

'High risk'

Martian salt streaks 'painted by liquid water'

Martian salt streaks 'painted by liquid water'

Secret source

Contamination question

More on this story

ABOUT

Tuesday, 29 September 2015

NASA's MAVEN Celebrates One Year at Mars

NASA's MAVEN Celebrates One Year at Mars

Nasa scientists find evidence of flowing water on Mars

Monday, 28 September 2015

Shell has made a costly call to abandon Alaska

Shell has made a costly call to abandon Alaska

Surprise move

'High risk'

Martian salt streaks 'painted by liquid water'

Martian salt streaks 'painted by liquid water'

Secret source

Contamination question

Share this story About sharing

More on this story