Life beyond Earth? There may be thousands more exoplanets in our galaxy

Kepler-186f, the first validated Earth-size planet to orbit a distant star in the habitable zone. NASA/EPA

The number of confirmed planets orbiting stars other than the Sun in our galaxy is rapidly growing. The unusual configurations and locations of these so-called “exoplanets” amaze and challenge our understanding of the universe. However the big motivation is to locate exoplanets that could potentially sustain life.

The habitable zone, or “Goldilocks zone”, around a star is the area within an orbital range of distance that allows for the right temperature to support liquid water – something we consider crucial for life as we know it. Now a joint team from the Australian National University and Niels Bohr Institute in Copenhagen suggest that we may have an even better chance of company than we previously thought. In research published in Monthly Notices of the Royal Astronomical Society, calculations suggest that the billions of stars in our galaxy may have between one and three exoplanets in their habitable zones.

It’s an exciting find. Looking at our own Solar System of eight planets we know the odds of life are low and that life in the galaxy may be rather lonely. We have Venus, Earth and Mars in or near the habitable zone around the Sun. But only the Earth was able to maintain its water. In the case of Mars the thin atmosphere allowed the planet to cool so the once flowing water is now locked up in perma-frost. In Venus’ case the water remains as vapour due to the extremely high surface temperature resulting from the thick carbon dioxide atmosphere. There has also been the suggestion in recent years that tectonic activity and a tilted axis of rotation axis results in seasons that are needed for life to evolve.

Life sustaining? T. Pyle, CC BY

An 18th-century law

The team base their new calculations on the assumption that the large number of already confirmed exoplanets in apparent isolation are actually part of larger planetary systems. This is a strong possibility given that high mass and short orbital periods mean exoplanets are much easier to detect than other types of planet. They then theorise the presence of these other exoplanets using the Titus-Bode law, famous for correctly calculating the position of the planet Uranus.

The Titus-Bode Law was formulated around 1770 and states the ratio between the orbital periods of planets in a star system. For example, the ratio between the time for Mercury and Venus to travel around the Sun equals the ratio in time between Venus and Earth. Any gaps in the sequence may suggest an as yet undetected planet in the system.

The researchers applied this law to 151 planetary systems in which the Kepler satellite (a dedicated transiting exoplanet survey mission) has found between three and six exoplanets. They found the law fit easily with the known exoplanets in 124 of the systems, which allowed the prediction of further exoplanets. In the remaining 27 systems the law could be applied if as-yet-undetected exoplanets were assumed to exist both in-between and beyond those already detected.

Conservative calculations

Of course this technique has the potential to predict exoplanets in ever longer orbital periods. So the group took a conservative path and “only made calculations for planets where there is a good chance that you can see them with the Kepler satellite,” according to Steffen Kjær Jacobsen, from the astrophysics and planetary science research group at the Niels Bohr Institute at the University of Copenhagen. This led to the prediction of between one and three exoplanets in the habitable zone for each of the 151 planetary systems studied.

Based on their statistics, Jacobsen then suggests that “a good share of the planets in the habitable zone will be solid planets where there might be liquid water and where life could exist”.

The team are now encouraging other researchers to follow up on a sub-set of 77 predicted exoplanets in 40 planetary systems within the Kepler data in order to test their theory. This subset of predicted exoplanets was chosen on the basis of their likelihood of transiting across the face of their host star from the perspective of an Earth-based observer.

Of course it is understood by the scientific community that life can exist in many forms and need not even be carbon based, as we are. But we have confirmation that carbon-based life forms which rely on water can exist – or your wouldn’t be reading this article. So the search begins with an attempt to find a second example of what we know exists before exploring other options.

Dawn breaks over distant Ceres ... and perhaps signs of habitability

NASA’s Dawn spacecraft is about to start its investigation of the largest member of the asteroid belt, 1 Ceres. It will take detailed images of the dwarf planet, and produce a geological map of its entire surface. But even before the spacecraft has reached its optimum orbit, the preliminary results just released are already surprising and delighting planetary scientists.

Up until February 2015, the best images taken of Ceres were from the Hubble space telescope, showing a near-spherical body with one area that was much brighter than the rest of the surface. As Dawn approached Ceres, its camera acquired some remarkable images, at about three times the resolution of those from Hubble. The pictures verified that there was indeed a brighter region.

Exploded map of Ceres showing ‘bright spot’. NASA

Even better, close examination of the images showed that the area varied in brightness over the course of Ceres’ day (which is only about nine hours long), growing dimmer as the dwarf planet moved into darkness. It is interpretation of this variability that has planetary scientists buzzing.

As if that were not enough, a further series of pictures appear to show a plume emanating from the surface. Is Ceres active? Does it have a layer of water or ice below a thin crust of rock? Could it be a ball of mud, overlain by a muddy ocean, on top of which is another thin muddy crust? The exact structure of Ceres is not yet known, although it is clear that it’s not rocky all the way through – its density is too low, so there must be at least some water or ice present. Suggestions at the 46th Lunar and Planetary Science Conference in Houston, Texas, of icy volcanism on Ceres have led to speculation that the dwarf planet could potentially be habitable. Although Ceres does not have an atmosphere, life might exist in a subsurface ocean, as has been suggested for Europa or Enceladus, moons orbiting Jupiter and Saturn respectively.

Is Ceres more slush than solid inside? NASA

Cryovolcanism – the presence of ice volcanoes – is not the only mechanism that can produce a plume of dust and ice from a planetary surface. The Rosetta mission has delivered amazing images of plumes coming from comet P/67 Churyumov-Gerasimenko, caused by sublimation of ice that releases dust and gas trapped inside the ice. Could the bright spot be an icy plume caused by the vaporisation of Ceres’ surface as it turns towards the sun’s heat, and then dropping away as night falls? Corridor talk at the conference speculates that Ceres might be closer to a comet than the asteroid it is usually regarded as.

Fortunately, we won’t have to wait much longer before we get some more definitive answers to questions of Ceres’ physical structure and heritage. By the beginning of April, the Dawn spacecraft will be much closer and will start its imaging campaign in earnest, at which point we will start seeing craters and other surface features at better resolution.

This is not the Ceres you are looking for. Borghese Collection, Louvre, CC BY-SA

In preparation for descriptions of such features, and bearing in mind that Ceres was the Roman goddess of the harvest, the International Astronomical Union has ruled that craters on Ceres should be named after international deities of agriculture and vegetation, while other features will be named after agricultural festivals of the world.

I’m not sure just how many of these there are, or how memorable their names will turn out to be. But as the Dawn mission’s principal investigator Chris Russell pointed out, there is one Mayan deity named Yum (Yum Kaax, god of agriculture and the jungle), who should readily be remembered. One can only hope the mission scientists find a suitably delicious feature on Ceres to give that name.

The first space walk happened 50 years ago, and nearly ended in disaster

Alexey Leonov steps into space for the first time. Leningrad Popular Science Film Studio

It is 50 years since humans first encountered space – not Sputnik’s first orbit, nor Yuri Gagarin’s first spaceflight – but the first time a crew member stepped out from their spacecraft’s relative protection and immersed themselves in the cold, hostile emptiness of the vacuum.

On March 18 1965, 30-year-old Russian cosmonaut Alexey Leonov completed a 12-minute spacewalk. This feat, and that of Gagarin and Sputnik before, was just one of the many achievements of the Soviet space programme in the early years of the space race.

Leonov and others who followed him wore specially designed space suits, were tethered and later had helpful gadgets to move them around. Without the tether astronauts would have floated into empty space, with nothing to slow or change direction in frictionless space, with no rescue possible and only an inevitable death as their oxygen supply ran out. If this sounds daunting, imagine being the first ever to have faced this.

Only recently have we started to develop robotic equipment versatile and sensitive enough to carry out the complex tasks requiring fine motor skills taken for granted in any lab on Earth. Before then, astronauts had to walk in space and use these tools to repair satellites – such as the Hubble space telescope, which has given us the incredible science and images for the past 25 years. Spacewalks helped ensure we could walk on the moon, take samples, and set up experiments.

Building the knowledge required to walk in space and the robotic equipment to help astronauts also led toward the establishing of the US Skylab and Russian Mir orbital space labs, and their successor in the International Space Station (ISS).

A walk on the wild side

Spacewalks, known as extravehicular activity or EVA, usually last six hours, more than 25 times longer than Leonov’s first attempt. As in all spheres, spacecraft technology has advanced significantly in the last 50 years. The technology in NASA’s Apollo mission to the moon is often compared to pocket calculators of today. You can run an emulation of the Apollo guidance program on your computer or mobile phone.

But the basics of astronaut flightsuits, largely the result of the work of the Soviet space program, are little changed today. Such suits can be daunting even on Earth: the helmet encloses the head and face and can cause feelings of claustrophobia. So imagine the calmness of mind required to cope when something goes wrong, beyond the help of fellow cosmonauts – exactly what happened to Leonov.

As he ventured from the Voskhod 2 space capsule, Leonov’s suit expanded as the pressure around him changed. Having spent ten minutes in space, his suit was blowing up like a balloon. If he didn’t act, the suit would start coming apart, and in any case it was too wide to fit through the airlock. He vented precious air inside the suit into space and as the effects of decompression sickness and the heat from the exertion began to take their toll, pulled himself back onboard the craft.

Commander Alexey Leonov (left) and flight engineer Valeriy Kubasov embark on their historic flight in 1965. NASA/USSR Academy of Sciences

Have we overcome such problems today? Certainly, many of these are now obvious issues that are understood and controlled. But are EVAs trivial acts of exploration and maintenance? Not by any means. Just last month, a water leak inside astronaut Terry Virts' spacesuit caused problems during spacewalks around the ISS. It brought back memories of a similar incident with a build-up of 1.5 litres of water in 2013 that almost led to an astronaut’s death.

Walking towards the future

Such problems won’t stop missions to explore space and other planets, nor should they. Humanity has overcome many hurdles to enter space, land on the moon, and create a space station. The new technologies and materials created for the space programmes have filtered into our lives in many other guises – from flame retardants and heat resistant materials, to ultrasound medical devices, water and air filtration, memory foam mattresses, freeze-dried food and prosthetic limbs.

It has also been a common cause for nations to work towards together. The space programmes and scientists of different nations now regularly work together to explore comets and visit other planets. The past 12 months have been especially packed with solar system exploration.

But we mark this day because a human walked in space. While probes and landers can achieve feats no human could, ultimately it is human hands that are needed to carry out experiments and explore. Not because we are better than robots but because we can deal with the unexpected, interpret the incomputable, and bring an emotional side to science. And, as every astronaut confirms, we bring back a view from space that changes us and our society. Thank you, Alexey Leonov.

Finches can pass H7N9 bird flu to chickens

In laboratory experiments, society finches spread H7N9 into water when they drank, in turn infecting chickens and quail that drank the same water.

Malik_Braun/Flickr (CC BY-NC-SA 2.0)

Finches, parakeets and sparrows are the ultimate source of H7N9 avian influenza, a new study concludes.

More than 600 people have contracted H7N9 bird flu in China, and more than 200 have died. Most of the people probably caught it from infected chickens, but it hasn’t been clear where chickens pick up the virus.

In laboratory experiments, society finches spread H7N9 from their mouths into water when they drank, researchers report in the April Emerging Infectious Diseases .

Chickens and quail could then be infected by drinking that same water, the researchers found. The virus does not seem to spread between birds through the air.

We are right to fear spy 'database of everything' if even politicians know little about it

(Security) Service with a smile. rogersg, CC BY-SA

The recently released Intelligence Service Committee’s report suggested an overhaul of the laws governing the work of the intelligence and security agencies. But beyond the headline announcement were buried details and admissions to questions that have gone unanswered for more than 40 years.

To find out why we must go back to 1972 when, as computerisation continued apace, concerns about the role of “data banks” grew into fears of large, centralised and intrusive databases containing details of everybody’s lives. In response the government set up the Younger Committee, which introduced ten principles to guide the growing use of computers for the processing of personal data.

When the government finally responded to the Younger report in 1975, it agreed that “government and private data banks should be considered and controlled together”. It also insisted that different data banks should not be linked unless “expressly sanctioned by law or agreement, or are subject to scrutiny and control” by the same authority.

These recommendations and the ten principles went on to underpin data protection law, from the first Data Protection Act in 1984 until today. This covers both private and public sectors, though there are exceptions for areas such as national security in this and those laws that succeeded it.

Historic moments of hardware destruction

Fast forward to February 10, 2011 when, after almost a decade of heated debate about a UK national identity card, the hard disks that contained the partial implementation of the National Identity Register database that underpinned the identity card scheme were physically destroyed.

It’s tempting to view the next similar hardware destruction, that of The Guardian newspaper’s computers containing Edward Snowden’s leaked files in July 2013, as a somehow ironic remark by GCHQ on the previous.

It was obvious to anyone that copies of the files remained elsewhere at The Guardian and the other media outlets involved in the scoop. The chain of events set off by Snowden’s revelations must now make us wonder whether GCHQ still holds a copy of that National Identity Register – and much more besides.

A database of everything

This issue raises its head in this report of the Intelligence and Security Committee, the UK parliamentary committee that oversees the work of MI5, MI6 and GCHQ. In response to the news stories based on Snowden’s leaked information in 2013, the ISC first stated that GCHQ had not circumvented or attempted to circumvent UK law – a claim received with cynicism by parts of the press, but barely challenged by politicians with the exception of the Home Affairs Committee – and subsequently launched an inquiry.

That inquiry’s final report reveals that the “database of everything” first feared in the 1970s had existed all along, in the form of Bulk Personal Datasets (BPDs) held by the intelligence agencies. Acknowledged for the first time, this strains the ISC’s earlier claims of adequate knowledge and oversight and no practices that stretch or break the law.

Not particularly enlightening. Crown Copyright

BPDs are defined in the report as “large databases containing personal information about a wide range of people”, some with millions of records. What kind of information this might be appears to have been entirely redacted. They are acquired “through overt and covert channels”, linked to other datasets where needed, and shared at will between the agencies and also with overseas partners.

For every past, current and future personal database (perhaps care.data?), we should now worry whether it is linked into this database of everything accessible to the security services not just in the UK, but perhaps other allied countries with very different views on data protection.

No insight, no oversight

The ISC is rightly concerned that “legislation does not set out any restrictions on the acquisition, sharing and destruction of Bulk Personal Datasets, and no legal penalties exist for misuse of this information”. There is almost no oversight in how they are created and used – even the home secretary and foreign secretary do not get involved beyond general discussions about BPDs. Instead, the agencies work with them on the basis of the Intelligence Services Act 1994 and Security Service Act 1989, and take unsupervised decisions on the basis of Human Rights Act’s principles of “lawful purpose, necessary and proportionate”.

The information security commissioner, Sir Mark Waller, does include BPDs in his review visits, though not on a statutory basis, nor with any mention in the publicly accessible part of his report. That the only immediate response to the ISC report from the prime minister, David Cameron, was to make BPD oversight a statutory task may be viewed as an indication that BPDs are seen as important.

A fusion of data across the Atlantic

In his recent book Black Box Society Frank Pasquale, professor of law at the University of Maryland, describes how so-called Fusion centres were established in the US after 9/11 to support the intelligence agencies and their industrial partners. These were US equivalents of this “database of everything”, where public and private data of all kinds – tax, health, traffic tickets, utility bills, insurance – were combined and sifted. Such databases would inevitably also include information about UK residents, and so it’s likely Fusion centre databases would also be part of any sharing arrangement with UK agencies' BPDs.

Data retention

The ISC report mentions many datasets throughout, such as those that include the “bulk collection” of “communications data”, or even the contents of private emails, texts and calls. In each case, the retention period is redacted. This lack of information should pose difficult questions for the agencies, considering retaining this sort of insufficiently targeted surveillance data was ruled unlawful by the Court of Justice of the European Union in 2014. Although it seems that by simply copying data into unregulated BPDs the agencies can retain the data indefinitely.

Going back to the original “data bank” fears, the usual questions reappear: what happens if BPD data is incorrect? What if incorrect data leads to action against citizens? Due to the National Security exemptions on data protection, there is no right to access, no right to correction and no right to redress. How are we to know if the data is secure and how would we find out if it gets abused by an insider – an eventuality that the report admits has already happened – or hacked from outside?

The database of everything feared in 1972 when computer processing power was exponentially smaller than today has finally come to light in 2015, at a time when far more data and data from far wider sources can be included. If even the government itself has only a tenuous grasp on the fact this mechanism exists, let alone a thorough oversight of it, we are right to be concerned.

Cyborg beetles reveal secrets of insect flight

A giant flower beetle sports an eletronic backpack containing a radio sensor that allows researchers to remotely control its flight.

Tat Thang Vo Doan & Hirotaka Sato, NTU Singapore

What better way to track beetle flight mechanics than by flying real, live beetles? To learn about the roles that different insect muscles play in free flight, researchers turned giant flower beetles (Mecynorrhina torquata ) into cyborgs. They outline their methods March 16 in Current Biology.

The team outfitted the beetles with tiny wireless sensors that record and send messages to specific muscles via radio waves. The scientists fired different muscles as the remote-controlled beetles navigated wider or tighter turns. They found that a muscle that folds wings also seems to be essential in right-left steering. The work confirms previous anatomical and tethered beetle studies, but the radio sensors could prove particularly useful in future analyses of insect flight.

Ecological engineering: a breath of life for marine ecosystems

The Swedish Byfjord: it may look healthy, but has a deep and stifling secret Author provided

Oxygen is essential for many life forms. But we don’t often give it the attention it deserves because we assume that it is always there. While oxygen is ubiquitous in our atmosphere, it is not necessarily the case for many bodies of water like rivers, lakes or even oceans. Here a lack of oxygen can result in significant impacts on the ecosystem like the killing of fish that subsequently float to the surface. But artificially oxygenating water can breathe new life, as we found recently while working with a fjord in Sweden.

Lack of oxygen and the death of wildlife is a phenomenon that can be observed not only in lakes but also in marine environments – which might seem surprising given the mixing of water by ocean currents. Oceans generally contain oxygen – we call them “oxic” – but we easily forget that this has not always been the case.

If we look back in Earth’s history the original oceans were without oxygen (anoxic) and had a significantly different water chemistry than today. With the advent of photosynthetic bacteria, the oceans became oxygenated over time. Initially the oxygen concentrations were fairly low (hypoxic) compared to present-day levels, but over time oxygen increased in the water and the atmosphere. This meant that hypoxic and anoxic areas were more and more on the retreat.

Nowadays, areas with hypoxic and anoxic waters are re-appearing all around the globe, from the eastern Pacific (several places on the west coast of Canada, the US, Central America, Chile, and Peru), to the Bay of Bengal (India), the Arabian Sea, the Black Sea, the Baltic and the Namibian shelf.

How do oxygen-deprived waters develop?

Different mechanisms drive the development of hypoxic and anoxic waters in different regions and will result in different water chemistries. In areas with upwelling of cold water to the surface (for example off the coasts of Peru and Chile), nutrient-rich deep water is transported to the surface. This causes blooms of photosynthetic bacteria and algae to form. The increased organic carbon in the water serves as a nutrient source for other microbes, and they in turn lower the oxygen concentration by respiration, creating hypoxic water.

In contrast, places like the Baltic have large and deep basins that have a naturally low frequency of water exchange (for example with the North Sea) and therefore receive little input of oxygen-rich water from outside. This often results in hypoxic conditions in these basins. In addition, non-treated waste-water, nutrient runoff from farmland and the dumping of organic waste increase the nutrient loading of Baltic waters. This results in blooms of photosynthetic bacteria and algae and, subsequently, the increased abundance of other bacteria which eat them. Their respiration draws down the oxygen concentration to a point where no oxygen is left.

Harmful algal blooms can develop and lower the oxygen content of the oceans Askewmind

Obviously, really low levels of oxygen (or its total absence) will be harmful to fish and many other life forms. Additionally, microbial processes that don’t require oxygen take over in waters where there isn’t any, creating further problems such as massive decreases in available nitrogen. When huge blooms of toxic cyanobacteria form, it is more likely that toxins will come into contact with humans.

Increasing surface temperatures in the oceans as a result of climate change will further decrease the oxygen content in surface waters, leading to the expansion of already known low to nil oxygen marine waters, and the formation of new ones. This is more than an ecological problem: the economy also suffers due to detrimental effects on fisheries, tourism and water quality.

Are there solutions? Yes and no. In some regions there is no obvious way to address the challenge. In others, such as the Baltic, remediation is possible and several ways to solve the problem have been suggested. Reducing the input of nutrients into the Baltic, for example, would treat the cause of the problem, and initiatives to improve waste-water treatment have been introduced.

Oxygenating the water

But we can also treat the symptom itself. One idea is to oxygenate the water by increasing the frequency of naturally occurring inflows of oxygen-rich water from the North Sea with the help of wind-driven pumps in an ecological engineering project.

Our Swedish colleagues tested this idea in a large-scale experiment in the Swedish Byford. Electrically-driven pumps were installed and the water column was mixed by pumping surface water to outlets in the basin that lacked oxygen. While the capacity of the pump was not high enough to introduce sufficient oxygen to completely oxygenate the basin, the disturbance of the water column triggered inflows of oxygen-rich water from a neighbouring oxygen-rich fjord. This resulted in a significant increase in oxygen throughout the water column, including the anoxic basin. Throughout this process we monitored the response of the bacterial community in the fjord using molecular methods.

Deployment of scientific equipment to determine the water quality in the Byfjord.

Testing the waters

Our recent work shows that oxygen-requiring bacteria, initially only present in surface waters, could also be found in the deep basin after oxygenation. They replaced the community of anaerobic bacteria observed there previously, showing that oxygen had reached the depths of the fjord and was supporting life. Overall it became clear that the change of the bacterial community was similar to what could have been expected in a natural oxygenation event, such as the mixing of waters.

Could ecological engineering to oxygenate anoxic marine zones be the solution for the future? Maybe. Reducing human inputs of nutrients into these zones is important, and these programmes should be continued as they address the root of the problem. However, ecological engineering is another option to oxygenate certain marine zones. This will especially help in systems where large amounts of nutrients are stored in the sediments; these would take a long time to be restored naturally even if all further nutrient input were stopped immediately.

But especially for the Baltic, the question is not only whether an oxygenation project is technically feasible or ecologically meaningful, but also whether it is economically viable and whether there is the political will to commit to a long-term project such as this.