Mountain Mars

It鈥檚 all about the long haul. The Hawaii Space Exploration Analog and Simulation (HI-SEAS) tasked six researchers with spending a , Mauna Loa. They were only allowed leave their habitat to explore the vicinity if they wore space suits. The team didn鈥檛 see another soul for an entire year, and all communications were put through a 20-minute delay, to mimic the reality of interplanetary existence.

Within the dome, the team experimented to find out which crops might grow best inside a Martian hut under LED lights and with limited water. They ate the results of these hydroponic experiments 鈥� 鈥� and also ate fermented foods they made themselves, including yogurt and cheese.

The crew celebrated Earth holidays and had a non-denominational winter celebration. Sheyna Gifford (pictured above), the mission鈥檚 chief medical officer, wonders if Christmas will make sense on another planet. 鈥淲hen are they going to do that on Mars given that the calendars don鈥檛 match?鈥� She suspects Martian settlers will probably invent new holidays such as 鈥淟anding Day鈥�, the date of the first human touchdown on the Red Planet. By the time a colonising spaceship arrives there, the crew will already have developed their own unique culture, Gifford reckons.

White Mars

The average temperature on the Martian surface is about -55 掳C, so prolonged exposure to bitter cold will be one of the main challenges of living on 聽the Red Planet. Last year, a crew of 13 overwintered at Concordia station (pictured) in Antarctica 鈥� in part to test the .

All wore activity watches which detect when another person wearing a watch comes close, to explore how their interactions changed over time. Crew member Beth Healey of the European Space Agency, a medical doctor, saw that the group divided into sub-groups based on when they were awake during the extended polar darkness, which lasted over 100 days. Some people tended to have chaotic sleep-wake cycles, while others clung to a traditional 9-to-5 work schedule using cycles of artificial light. 鈥淵ou could really only be friends with people who were up at the same time,鈥� says Healey. Enforcing common mealtimes helped the different groups communicate.

Healey also examined her colleagues鈥� video diaries to see if the way they talked about their lives changed throughout the mission, and looked at brain scans taken before and after their stay. Findings from this research are yet to be published, but brainwave recordings of crews on a past mission showed that their brains were surprisingly resilient to the prolonged dark and isolation.

Though the winter was brutal, Healey noted in her blog that . 鈥淚t was strange to see how quickly money can become meaningless,鈥� she wrote, because the base does not use currency. Instead, improvised gifts from crew members became strangely valuable. 鈥淎 tinfoil penguin and a lampshade made from can ring pulls and stones were among my favourites.鈥�

Desert Mars

In a remote corner of Utah, the Mars Desert Research Station has other Red Planet analogues beaten for sheer barren glamour. 鈥淚t鈥檚 a half-hour drive from the town of Hanksville, and Hanksville has the motto, 鈥榃here the hell is Hanksville?鈥欌�� says at the Canadian Museum of Nature in Ottawa, who recently did a stint as a crew biologist at the station.

The facility is owned and run by the , and houses 鈥淯tahnauts鈥� in a cylinder-shaped habitat designed to look like something dropped off by a rocket. Whenever they head out through the small airlock, they wear orange jumpsuits and bubble helmets that have a nasty habit of fogging up.

Enough rain falls there to let some small shrubs, fungus and soil microbes grow. Sokoloff鈥檚 project was to survey this 鈥淢artian鈥� flora. Astronauts won鈥檛 be picking sagebrush or mushrooms on Mars, but the soil-dwelling bacteria Sokoloff collected could reflect the survival strategies of Martian microbes, if they exist. The methods used to carefully isolate those extreme life forms from the soil are much like what future Mars botanists must resort to. Some microbes change the structure of the rocks and soils that host them: if similar structural shifts turn up on Mars, it could signify life.

Wet Mars

Mars鈥檚 surface gravity is only two-fifths that of Earth鈥檚, and Mars has no breathable air 鈥� so what better place to mimic its suffocating floatiness than under the sea on Earth? 聽This is the premise of the Aquarius Reef Base, a small habitat 19 metres down off the coast of Key Largo, Florida. In July last year, six aquanauts spent 16 days living down there 鈥� the 21st instalment of the .

The crew tested equipment inside the habitat, and carried out simulated spacewalks on the seabed. The lessons learned there could be invaluable for future, low-gravity missions, to Mars and beyond.

FEELING blue? A new algorithm can predict depression from photos people post on Instagram and may in future prompt a visit to the doctor.

Andrew Reece at Harvard University and Chris Danforth at the University of Vermont in Burlington surveyed the mental health of 166 people, then set an algorithm to comb through 43,950 photos posted by them on social media, looking for features correlating with depression.

Depressed people, it turned out, tended to post blue-toned or dim photos, or use black-and-white filters. They were also more likely to post photos with faces, but with fewer faces per photo. Danforth says this might mean lots of selfies, part of the focus on self that occurs in depression, or it may mean the person is spending less time with friends or family ().

The algorithm used these features to predict depression 70 per cent of the time 鈥� better than the 42 per cent average accuracy of human doctors.

鈥淚t鈥檚 very inexpensive 鈥� it鈥檚 something that could be an app on someone鈥檚 phone,鈥� says Danforth.

However, it could be tricky for doctors to access this data. 鈥淢ost physicians are reluctant to view social media profiles of patients due to worries about confidentiality,鈥� says Megan Moreno at Seattle Children鈥檚 Hospital.

This article appeared in print under the headline 鈥淚nstagram posts can hint at depression鈥�

It鈥檚 a squid-eat-squid world down there. Remotely controlled submersibles have filmed two deep-sea species of squid gulping down members of their own species.

Several species of squid, including giant squid, are known to eat each other.

But we have mainly gleaned this from their stomach contents, and it wasn鈥檛 clear if this was normal behaviour, or something they did when they have been caught in a net, says at the GEOMAR Helmholtz Centre for Ocean Research in Kiel, Germany.

鈥淎nimals get stressed in a net,鈥� he says. 鈥淭hey probably start doing something called 鈥榥et feeding鈥� 鈥� they feed on anything that is close by.鈥�

Hoving and his colleagues sent down subs to observe two species of the Gonatus genus of squid in an underwater canyon of Monterey Bay, off the coast of California. The squid span much of the water column, from shallow waters to more than 2000 metres down.

Caught cannibalising

The subs frequently saw both species eating their own kind, especially Gonatus onyx. 鈥淯p to 40 per cent of the animals examined were feeding on animals of the same species,鈥� says Hoving. 鈥淭hat was quite high 鈥� that was surprising.鈥�

The subs filmed the squid doing this in their native habitat, so it could be ordinary behaviour for them, Hoving says.

The squid grow quickly and breed only once, needing lots of food to fuel their metabolism, says Hoving. When other food is scarce, cannibalism could be a good way to get food, he says.

There are other benefits, too. 鈥淚t eliminates one competitor for food,鈥� he says.

鈥淐learly cannibalism is important,鈥� says at the University of South Florida in St Petersburg. 鈥淭hey鈥檙e doing it on a semi-regular basis or you wouldn鈥檛 see it from a submersible.鈥�

Don鈥檛 eat too many

But it wouldn鈥檛 make sense for the species to overindulge in itself, Seibel says. 鈥淎 species can鈥檛 exist feeding only on itself.鈥�

Using subs with high-powered lights to observe the creatures could have led to the amount of cannibalism being overestimated, Seibel says. It鈥檚 possible that squid clutching large prey items 鈥� such as their kin 鈥� are less able to swim away from the vehicle, meaning that they鈥檇 be counted more often than squid eating lighter meals, he says.

To get the most accurate picture of the elusive animals鈥� behaviour, you have to combine observations from subs with other methods such as netting, he adds. In general, these squid aren鈥檛 picky eaters, says Seibel. 鈥淭hey eat just about whatever they can get their tentacles on.鈥�

Palatial housing

Some of the best lessons come from the school of hard knocks. But some kit is too delicate or expensive to be subjected to this. So researchers have instead taught cheap, expendable drones to pass on their hard-won knowledge to their more precious peers. Getting robots to learn and share general concepts in this way could also make them better at independent decision-making.

Teaching an artificial intelligence to fly an expensive vehicle is risky, since it needs to know what both success and failure look like. 鈥淟et鈥檚 say you want to train it to fly a really big helicopter,鈥� says at the Jet Propulsion Lab in Pasadena, California. 鈥淵ou need it to crash a lot to get it to learn what a crash is 鈥� but that鈥檚 often not possible.鈥�

Not wanting to risk a new, expensive drone, Daftry and colleagues took a cheaper vehicle and piloted it through a forest, sometimes taking it between obstacles and sometimes crashing it. Trial and error let the robot figure out how to fly safely by itself.

The researchers then took the drone鈥檚 abilities and transferred them to their more expensive craft, which was immediately able to use the second-hand know-how to avoid flying into trees itself.

Dog-brained drones

The trick to passing on an ability that can be adapted to fresh situations lies in the way the first drone learns. Teaching an AI sometimes works like dog training 鈥� the robot gets a treat or a slap on the paw depending on its choices, says at the Massachusetts Institute of Technology.

But in this case, the drone first has to learn what鈥檚 a treat and what鈥檚 a slap 鈥� then it writes its own rules based on its experiences. 鈥淚t鈥檚 trying to work out for itself what its own reward should be,鈥� says Roy.

The upshot is that the initial drone picks up general-purpose rules. Rather than learning specifically that it should go left when it sees a brown patch 鈥� a tree, say 鈥� it learns that a brown patch is bad and must be avoided in any way possible.

The strategy should work for many kinds of robots, says Roy. Getting robots to pass on general concepts they have learned makes them much more independent, he says. 鈥淚t鈥檚 a change in how we think robots should make decisions.鈥�

Reference: ArXiv,

Read more: How drones are learning to find their own way in the world; Moth navigation probed to improve micro-drone flight

Old blue eyes

150-year dry spell

Pining for the fjords

One day your hard drive could just be a pile of plastic. Researchers have coded a word into short chains of plastic molecules, which could be used as a space-saving way to store our mountains of data 鈥� or even to reveal counterfeit goods.

DNA has shown some promise in holding millions of bits of information in a tiny volume. But DNA is fragile and hard to write and read. So at the Institut Charles Sadron in Strasbourg, France, has been experimenting with more customisable chains of plastic molecules that can encode information in similar ways.

Also known as polymers, these chains are made up of two kinds of molecules that stand for the 1s and 0s of digital computer code. Previous research has seen data stored in single long chains, but these become harder to read as the length increases, so the storage record stands at just 10 bits.

Lutz鈥檚 team had a different approach. 鈥淚nstead of making very long chains, the idea is to create a library of very short chains,鈥� he says.聽 As a demonstration, the team wrote the acronym CNRS, the abbreviation for the French National Center for Scientific Research, across six polymers 鈥� a 32-bit message when encoded using standard ASCII characters.

The researchers read the message by sorting the chains from shortest to longest using a mass spectrometer and then sequencing the chains by breaking them apart molecule-by-molecule. The shorter chains, less than a nanometre each, are easier to manage than one long one, while their varying length keeps the data in the right order.

鈥淚 think it鈥檚 an encouraging step,鈥� says at the University of Washington in Seattle.

Stolen goods

To store big chunks of information, researchers will have to scale up the technology to make large libraries of chains, Ceze says. In addition, it would be quicker to write data into the molecules if the chains could be synthesised in parallel rather than one at a time, he adds

While writing and reading these polymers is currently expensive, there are some high-end uses for them. Embedding coded polymers in pricey electronics or artworks could label them with the maker鈥檚 or owner鈥檚 identity, says Lutz. Reading a sample of the molecule chains would let investigators discover the source of the object, helping them find counterfeits and stolen goods.

Both DNA and synthetic polymers have the potential to shrink the size needed for data storage, says at Boise State University in Idaho. That鈥檚 important, since the world鈥檚 data is piling up faster than our ability to store it. In 2040, the amount of space needed to keep our data in silicon chips could be as large as a small country, perhaps twice the size of Liechtenstein, he says.

Using several types of molecules would let researchers write in a code that packs more information into shorter sequences than binary 0s and 1s can, says Zadegan. While scientists have introduced two artificial letters into DNA for a total of six letters, it could be simpler to design an entirely new plastic molecule alphabet. 鈥淭hese polymers are perhaps easier to deal with if you want to expand the language,鈥� he says.

Journal reference: Angewandte Chemie International Edition, DOI:

Read more: Plastic fantastic: The quest to create the smartest materials