Japanese astronaut Soichi Noguchi may have made the mainstream media with his photos from the international space station some years ago, but ask the average person in the street to name the big players in space, and I’m willing to bet that Japan wouldn’t be at the top of their list.
Us space geeks on the other hand may know a bit more about their space activity. Perhaps it’s a fondness for the Japanese Kibo module on the ISS, an ability to name several of their astronauts (Koichi Wakata, Chiaki Mukai, Soichi Noguchi etc), awareness of the H-IIB ISS resupply rocket, or excitement about their asteroid sample return mission Hayabusa2.
But did you know that Japan has quietly been running a programme to promote space activity in countries that have previously had none? I didn’t. Well, not until a recent request to talk about Ghana’s first satellite – GhanaSat-1 – on BBC World Service programme Click Radio. I knew that CubeSats have been launched from the ISS and indeed, from the Kibo module, but this was the first time I had put some effort into researching them further.
I’m pretty excited about what I found out, and I don’t recall reading much (if anything) about Japan’s “Birds” programme, so I thought I would write something myself.
The “Birds Project” is a cross-border interdisciplinary satellite project for non-space-faring nations that is run by the Kyushu Institute of Technology and supported by Japan. Birds-1 saw five nations each develop and operate a 1 kg CubeSat (10 x 10 x 10 cm), which was then delivered to the ISS on a SpaceX Dragon capsule in June 2017, and deployed on 7th July 2017.
Birds-1 CubeSats by their respective nations’ flags. Credit: Birds Project
For Ghana, Mongolia and Bangladesh, this marked their first foray into space – a fact celebrated by the president of Ghana, Nana Addo Dankwa Adufo-Addo . Nigeria and Japan were the other countries involved with building satellites, and Thailand and Taiwan built ground stations to support the mission.
It was a project of firsts: the satellites were delivered on SpaceX’s CRS-11 mission, the first time a re-used Dragon capsule has revisited the ISS (having been used on CRS-4 in 2014), it was the first space mission for Ghana, Mongolia and Bangladesh, and formed the first five CubeSat network with seven ground stations.
The CubeSats were deployed from J-SSOD – the JEM small satellite orbital deployer (JEM being the Japanese Experiment Module – a.k.a. Kibo). The CubeSats are delivered to the ISS ready-packed into satellite install cases, and astronauts onboard the station fix these to the multi-purpose experimentation platform (MPEP) pass through the airlock on a special slide table to the exterior of the space station. From there, the Japanese Remote Manipulator System (robotic arm) picks up the MPEP and moves it into the correct site for satellite release.
— Jack Fischer (@Astro2fish) July 7, 2017
When launching CubeSats from the space station, you must be sure that you launch them into an orbit that will not clash with your own – else you could risk colliding with them, which would be at best, unfortunate, and at worst costs the lives of the station crew and perhaps the station itself!
The orbit of CubeSats launched from the ISS depends on the station’s altitude at release, and the ballistic force that they are launched with. They go into an elliptical orbit of an altitude of between 380-420 km and their life expectancy (before the orbit deteriorates and they burn up in Earth’s atmosphere) is anything between 100 to 250 days.
Birds-2 is already well underway, and successful launch of CubeSats from that mission will enable Bhutan, Malaysia and the Philippines to join the list of space-faring nations.
Space is a brilliant source of inspiration and opportunity for new research and data that has a real tangible benefit to people on the ground, but it is costly. For nations that do not already have the infrastructure required to take part in space activities, the barrier to entry due to costs and technical expertise can be too high. This is especially true for countries that may still be thought of as “developing countries” in an Earthly sense, and yet they may stand to gain enormously from Earth-observation data that can be collected from space.
BRAC Onnesha – the Bangladeshi CubeSat – will take high resolution images to analyse vegetation, urbanisation, floods, forestry and water availability. GhanaSat-1 has high- and low-resolution cameras and will be used to monitor their coastline, as well as testing the effect of space radiation on commercially available microprocessors. They’re also going to play the Ghanaian national anthem and songs of independence in space!
The team behind the Bangladesh’s first satellite, BRAC Onnesha Credit: BRAC Onnesha
Importantly, this is an issue of inclusivity. Space belongs to no single nation, and access to it should not be limited to those nations lucky enough to have a historic national space programme, or enough cash to build one. Space exploration is increasingly considered an international endeavour, and it is important to me that we involve as many nations as possible. Those countries with expertise and facilities should offer a helping hand to those without access to the same opportunities as them. In the end, the more minds and perspectives we have working to solve the problems of long duration space travel, the better.
Congratulations to the whole Birds-1 Project Team for their successfully satellite deployments!
Bravo to Japan for opening these opportunities for non-spacefaring nations – and here’s hoping that the teams’ success will spark a bigger interest in space in their home countries. The ability for space research to transcend national borders and politics is something that makes it special – let’s not leave anyone behind.
Mine is a blog about space, not about politics, but this is important to me – vitally important. Jo Cox’s life and actions, as well as these words, have inspired me to speak out.
Major Tim Peake is a European astronaut of British descent. He is a European Space Agency (ESA) astronaut. His selection to the ESA astronaut corps came before the UK Space Agency even existed.
It is correct that Tim is the first non-commercially-funded Brit in space, but none of that would have been possible if it weren’t for the European Space Agency, and the co-operation that comes from the member states.
No, ESA is not the same as the EU. Yes, we do pay subscriptions to be a member.
But we get money back, on a system of “juste retour”, whereby money paid into the European Space Agency is then invested back into the member states on a proportional basis.
There are certain aspects of ESA that every member country must contribute to, and then there are the “optional” programmes. Things like – you’ve guessed it – human spaceflight.
At the time that Tim Peake was picked in 2009, the UK did not put any money into human spaceflight at all. In fact it rankled a few nations that he was even picked for the astronaut class of 2009 because it meant that countries who were paying in to the human spaceflight stream were paying for the training of citizen of a country who put nothing into that pot. But Tim Peake was an excellent candidate. By all accounts I’ve heard – including from those on the selection committee – he was such a stand out candidate it didn’t matter that the UK wasn’t paying for his training, he earned his place.
Since then, the UK has dipped its toe into programmes such as ELIPS (the European Programme for Life and Physical Sciences) – allowing British scientists access to ESA’s microgravity research platforms, including the space station. This have been a huge boost to scientists working on space biomedicine in the UK. In 2012 we finally committed some money to the human spaceflight budgets also.
Did we cover the cost of training and then flying Tim to the space station with these investments? No. But, thanks to the co-operative nature of the European Space Agency, we were able to benefit from investments and resources from other countries.
During the EU referendum campaign there has been a lot of talk about protecting “Great” Britain and our achievements, how we would be better off out of the EU, but much less about how working together, and co-operating with other EU nations can also be a really great thing. Greater than the sum of its parts even.
So to all those people claiming Tim Peake for Britain, to all those editors too lazy to point out that he is actually a European astronaut, or even mention ESA, I ask you to stop and think, and reflect the fact that without the European Space Agency, you wouldn’t have a story to write at all.
Don’t pretend that we did this on our own. It’s a lie. Don’t just feed into the idea that we don’t need strong relationships with Europe, or that Britain will be magically better on its own, out of the EU. Remember that co-operation is sometimes the only way that we can achieve great things – like getting to Mars. No one nation could do that alone, and no one nation sent Tim Peake to space. It was a joint effort, and I’m tired of having to point that out to people.
There are big problems in the UK, huge shortages of housing, underfunding of schools and the NHS, pressure on our resources, but to blame all that on the EU, without taking a closer look at the way our country is run, is short-sighted, and dangerous.
Generation Z has a much more global perspective, and yet they are the ones who could inherit a nation that has cut its ties with its closest neighbours thanks to the EU referendum.
Look up to space, spot the international space station and think of the way Russian, American, European, Japanese and Canadian astronauts all work together, to keep each other safe and make progress. Of course it’s not always easy to co-ordinate multiple nations, but by standing together we can do so much more. So before you revel in the great achievements of Great Britain and “our” Tim Peake, remember that without our European and global partners, Britain wouldn’t have even got off the ground.
Captain James “Jim” Lovell, a veteran of four space flights, was part the Apollo crew that flew closer to the Sun than any other, and also holds the unfortunate accolade of being the only person to fly to the Moon twice and never step foot on it.
At 87, he’s starting to look a little frail, but that doesn’t stop him holding court for over an hour in a room packed with space enthusiasts. I’m back in Pontefract for the latest in the incredible series of Space Lectures and I, like the rest of the audience, am totally captivated by Captain Lovell.
“There are three types of people in the world”, says Lovell. “Those who make things happen, those who watch things happen, and those who wonder ‘what happened?”. Lovell certainly has had a life filled with adventure, so I’d have to conclude he fits squarely in the former group.
Lovell took part in the first astronaut selection process in 1958, making it down to the last 32, but he lost out to John Glenn, Wally Schirra and the other five guys who went on to become known as the Mercury 7. “I don’t know why” he says, with a glint in his eye.
When the second astronaut selection process took place – this time for the Gemini programme – he applied again.
“By gosh I was selected” says Lovell, with a hint of excitement still present in his voice. “It was the golden age of our space activities” he says, “the whole population was excited about space”.
Lovell flew on Gemini 7, which he describes as a medical flight. At that point there was still a lot to be learnt about how the body would survive in space. “Some of the doctors didn’t think we could live in zero-gravity” he says. “We evolved in a gravity-based environment, perhaps we needed gravity for breathing and swallowing?”
NASA calculated that maximum time it would take to get to the Moon and back and based the length of the Gemini 7 flight on that to test the body’s reaction to space. At just a fraction less than two weeks in duration, Gemini 7 was the longest of the Gemini missions. The flight had 23 experiments on board “and it was really bad news!” says Lovell, reminding us that the size of the craft is “smaller than a VW”.
“We were guinea pigs” says Lovell, explaining they wore EEGs on their heads, heart rate monitors, and blood pressure cuffs on their thighs – which “blew up for two minutes, then off for six minutes, then again for two minutes.. we were there two weeks!”
One of the experiments was to look at the change in calcium level in the body, and whether that changed when they were in space. You need calcium to keep your bones strong on Earth, but what about in microgravity where your bones are not subjected to the same force? Would the calcium just “flow off”?
For two weeks before their flight everything about them was monitored, how much they ate, drank, and even how much they perspired. The team knew exactly what food they were eating in space and then measured everything for 10 days after the flight while they were in isolation in order to see if there was any change in their calcium levels.
The experiment sounds arduous, to say the least, and Lovell wryly announces “Ladies and gentlemen – I can tell you that a two week mission is not the right length of time to do a calcium balance study”. He’s right of course, and studies on calcium balance in space continue to this day, with Scott Kelly and Mikhail Kornienko currently on the space station carrying out a year-long mission.
There were important things learnt on their mission. Muscles become weak and microgravity has an effect on blood flow and the heart. “Our heart rate was 10 beats per minute slower, and the volume of blood decreased” says Lovell. First the crew was told that they should drink more water, but actually you don’t need quite so much blood in space, since it doesn’t pool down in your feet and legs like it does on Earth.
“My second flight was kinda different” says Lovell, talking about Gemini 12, the final mission of the Gemini programme.
On Gemini 4, Ed White did the first US spacewalk, he went out attached to oxygen supply, and he floated. On Gemini 9, 10, and 11, NASA tried to get astronauts to do work while on a spacewalk.
“They all failed” says Lovell, “their bodies became overworked”. “We had forgotten the third law of motion, for every action there is an equal and opposite reaction”. Each time they touched the spacecraft it would react, and that was causing problems.
Some “brilliant engineers” came up with the idea for the neutral buoyancy lab – or in those days, a swimming pool with a mock-up space module in the water so they could practice spacewalks. Lovell recalls crewmate Buzz Aldrin in a spacesuit in the pool being reminded “don’t swim” – because in space that would of course be impossible. This allowed them to plan the foot and hand holds on the craft, and “it worked quite well” says Lovell. Gemini 12 was the first mission to show that extravehicular activity was feasible. Nowadays training in huge pools is a standard part of training for astronauts.
Lovell’s third flight, Apollo 8, was never meant to fly to the Moon, but “1968 changed it completely”. The US received information that Russia was going to fly a crew around the Moon in the autumn of 1968, but they had several failures during the Zond programme. “The re-entry wasn’t right” says Lovell, referring to Zond 4. The Russians successfully sent Zond 5 around the Moon in September 1968 with a crew of tortoises, flies, worms and plants, but there were still some concerns and this led to many arguments back and forth around the safety of a crewed mission.
During this time, things were progressing in the US, though not entirely as planned. Grumman, who were building the Lunar Module (LM) announced that they “can’t make and deliver the LM in 1968”. This caused a bit of an issue for Apollo 8, which was slated to test the LM in Earth orbit, and take the Command Module (CM) to a high altitude so that they could reach Moon-return speeds and test the heat shield on the CM.
“Without the lunar module, what should we do?” asks Lovell. It was decided that if Apollo 7 tested the CM and it was a successful test, Apollo 8 would be changed so that it would go all the way to the Moon, circumnavigate it, and come back.
It was in summer 1968 that they got word that the mission had changed, and they were scheduled for launch in December the same year. “I spent many a day at MIT learning new guidance systems to navigate to the Moon” says Lovell.
“1968 was kinda a bad year, especially in the US” says Lovell, “there was Vietnam, riots, assassinations” so it was an important mission in terms of morale.
Apollo 8 launched on December 21st 1968, “the navigation was successful, and we saw the ancient old craters on the far side of the Moon” says Lovell. “We were like three school kids looking through a candy store window.”
“We were looking for landing sites on the nearside of the Moon” explains Lovell. “We saw this Earth come up from the lunar horizon – really a fantastic sight – the whites and blues of the Earth, the tan of the deserts”.
The resulting photograph – famously known as “Earth-rise” – springs to instantly to mind, but here is someone remembering seeing that sight for real.
“Earth” he says “just 240,000 miles away, looked totally uninhabited, just tucked away by a normal star, tucked in a normal galaxy”.
“How fortunate we are that we have this place to live” he says wistfully. “People often say when you die you go to heaven, but ladies and gentlemen, you go to heaven when you’re born – this is the place that is really heaven.”
Lovell says that Apollo 8 is the most significant flight of his career, and since he was commander of the drama-filled Apollo 13 mission, I’m quite surprised to hear that.
“Apollo 13 was a flight that was plagued by bad omens from the beginning” he begins. “Years before we flew, the company producing the oxygen tanks dropped one on the floor, it was refurbished and it should have been fine”.
That fateful tank wasn’t even meant to be used on Apollo 13, it was meant for Apollo 10, but it got switched. Jim Lovell himself was switched from Apollo 14, it was Alan Shepard who was due to fly on Apollo 13. Agreeing to the swap just six months before the flight, his wife was less than impressed with the decision, saying “you did what?! Don’t you know about 13?” How those words must have haunted her…
The crew did a countdown demo test, with the big booster, all consumables, but no fuel. Everything was timed down to zero to check all the systems worked. The test was perfect – “no problems” – but after the test, as the ground crew tried to remove the oxygen tanks, one tank wouldn’t come off. It was that tank, the one that had been dropped all those years earlier.
Inside the tank there was a little heater that was used to burn a little of the oxygen off, the ground crew decided that they could save a bit of time by leaving the tank where it was and burning off the oxygen using the heater. One problem, in flight power for the rocket systems was 28V direct current, while the ground power was 65V DC.
This high voltage welded the contacts from the thermostat together, meaning that instead of shutting off the heater when the temperature was too high, it was actually able to heat the inside of the tank to around 900 degrees Fahrenheit, melting the Teflon inside. The result was that on launch day, when they filled this tank with oxygen, “it was a bomb waiting to go off”.
That wasn’t the only piece of bad luck. The crew were exposed to measles, and while the others were okay, Ken Mattingley, a bachelor, was not immune. He was dropped from the crew and replaced by Jack Swigert.
“It sort of felt like a bad omen coming true” says Lovell, “but we had a good guy with Jack”.
So we get to launch-time for Apollo 13 – 13:13 CST on April 11th 1970. The first stage was perfect, and was jettisoned fine, and then the central engine in the second stage shut down. It was a good job as Lovell says, “if not it would have disintegrated and taken the other four”.
The crew orbited Earth and everything seemed okay, so they set off a free return course to the Moon – whereby you “coast” at 24,000mph all the way to the Moon and then the Moon’s gravity helps to swing you back for a safe return to Earth. All the Apollo missions, from 8-17 started on a free return trajectory.
Mission control came through on the radio to let them know that if they wanted to land at Fra Mauro they need to change the attitude of the spacecraft slightly. This now meant that if an engine failed, their course would take them to the Moon, they’d go round and come back to Earth, but they would be 40,000 miles away – too far to be caught be Earth’s gravity.
On April 13th (of course!) the now famous explosion occurred. Once again Lovell was faced with a change to his mission, except this time the change was “from landing to survival”.
The crew wondered if they had been hit by a meteor and set about trying to close a hatch so that they could maintain pressure in their part of the craft at least. Jack Swigert tried several times but couldn’t manage it, neither could Lovell “so we put it on the catch and tied it down” he says.
“We realised that we weren’t dead yet, so it wasn’t a meteor” says Lovell, deadpan. Out of the window he could see a substance leaking out. “It dawned on me that we were losing oxygen” he says, “the gauge on one tank was at zero, and the needle on the other was coming down”.
“I knew the only way to come home would be to use the lunar module as a lifeboat” he says.
Mission control couldn’t – indeed didn’t – believe it at first, after all, there are so many back-ups in place.
They lost telemetry, then radio for a while, then mission control decided “you know what this is? It’s a comms problem”. Perhaps it was a solar flare they thought, that’s probably the only problem, “but we knew what had happened” says Lovell.
“The LM is a very fragile device” says Lovell, “the material is so thin you could punch a hole through if you wanted too, and it was designed to last for 45 hours, with two people”.
“After the explosion, I kept counting the crew” he says, “one, two, three”.
“How do we get home?”
The first thing the ground came up with was to get them back on a free return course so that they would “somehow intercept Earth”. Still, that sounded better than skimming round the Earth at 40,000 miles altitude, returning to the Moon, and going round and round, he says.
“Is the command module dead?” they asked. “Yes” replied Lovell. “Well you can use the lunar module as a lifeboat”. “Yes I’ve already thought about that” said Lovell.
Using the attitude control system (ACS) on the lunar module they tried to change the spacecraft’s attitude, but it was never designed or tested to work when still connected to the command and service module. This added 60,000lbs of dead mass that wouldn’t normally be fighting against the ACS on the LM. The centre of gravity was in the wrong place and that caused problems, but the apparently unflappable Lovell merely comments that “you’d be surprised, how quickly you learn when you’re in trouble”.
The next crucial manoeuvre involved blasting the engine while they were on the far side of the Moon in order to speed up their return time. But there would be no communication connection with mission control from behind the Moon, so it was incredibly important that they noted the instructions and timings down correctly before they lost contact.
Lovell, as Commander, asked for the rest of the crew to listen for instructions too, to make triply sure they took them down correctly. “Are you ready to copy?” said mission control, and Lovell realised that his two companions weren’t even listening.
“They were looking at the Moon, with cameras, taking photographs”. When he chastised them they said “well, you’ve been here before!”
“They were so interested in the far side of the Moon that they forgot we were in trouble” says Lovell. “I reminded them, if we don’t get home, you won’t get your films developed!” somehow still able to make light of their situation.
They switched on the engine for four minutes, and then “we switched off the ‘exotic’ systems that you can do without” says Lovell, listing off guidance computer and autopilot among them.
“We were left with only the radio, and a fan to keep air circulating” he says. “Things were kinda quiet”.
“When it’s quiet and you’re in a tight spot, you start to think” says Lovell. Swigert worried that they might exceed escape velocity, and Lovell reminded him they were back on the free return trajectory.
“Don’t worry, we have it made” he remembers saying, “but I was wrong”.
Returning to Earth from the Moon is a tricky business, you have to return at a specific angle, no less than 5.5 degrees, no more than 7.5 degrees. “If you come in too shallow, you skim off, too sharp, and you’ll burn up”.
As it turned out, they were now set to miss Earth not by the original 40,000 miles they were worrying about, but by 60,000 miles. Something had to be done, and without the help of those “exotic” systems they’d been forced to switch off to preserve power.
In an unusual piece of good fortune for Apollo 13, there was one emergency manoeuvre, tested on Apollo 8, that could help them – and as luck would have it, it was actually Jim Lovell who had helped to develop it. The procedure involved getting Earth in the window of the LM, and using the Earth’s terminator (the line when day and night meet), as a navigational aid, allowing them to fire the engine and change course, as famously (though somewhat overdramatically) depicted in the film ‘Apollo 13’.
More accurate was the portrayal of the issue of the crew being poisoned by the carbon dioxide in their own exhalation. The CO2 scrubbers in the LM were round, but in the control and service module they were square, and since you (in this case literally) can’t put a square peg in a round hole, a team on the ground worked hard to find a way of converting one into the other, using filters, duct tape and other bits of kit available to the crew in order make it work. They sent up these instructions and the crew was able to solve the problem.
There were still concerns about landing. Had the heatshield been damaged? Would the pyrotechnics deploy the parachutes after having been so cold? Thankfully the the crew splashed down safely, ready to be picked up by the aircraft carrier US Iwo Jima.
Once onboard they radioed back to Johnson Space Center in Houston – “they were happy, but probably ripped up all the obituaries they wrote for us” says Lovell.
Apollo 13 had made headlines around the world, with millions of people praying for the crew’s safe return, and 55 countries offering water rescue assistance. “Even Paraguay and Czechoslovakia offered their help” says Lovell, “and they don’t even have coastlines!”
For years Lovell was frustrated and disappointed not to have stepped foot on the Moon, but now he’s had a change of perspective. “Apollo 13 brought out what we could do in a crisis” he says.
He explains how he often wonders what would have happened if Apollo 13 had been successful. “It dawned on me that perhaps the best thing that could have happened was the explosion”.
“Without the explosion, there would be no ‘Houston we have had a problem’, no ‘Failure is not an option’”.
“We’d have picked up some rocks, said some forgettable words, and been forgotten”.
It’s been an exciting 24 hours for the online (and indeed offline) space community – first there was the “Super Blood Moon”, where a lunar eclipse allowed the Moon take on an eerie deep red colour in the early hours of Monday morning, and then NASA revealed what its much-anticipated big announcement trailed as “Mars Mystery Solved” was all about.
“Mars is not the dry, arid planet that we thought of in the past” said Dr Jim Green, Director of Planetary Science at NASA at a media event on Monday afternoon. “Today we are going to announce that in certain circumstances, liquid water has been found on Mars.”
Cue much excitement and many bold headlines, but let’s just take a breath and find out what’s really going on…
Well, yes and no. In 2008, NASA’s Phoenix Mars Lander confirmed the presence of water ice near the surface of Mars, but it’s liquid water that people are especially interested in, as this is considered to be a key to life.
In 2013, Mars Curiosity rover’s SAM (Sample Analysis at Mars) instrument found that a sample of Martian soil it had scooped up and analysed was 2% water. While not liquid, it was noted as being a relatively high percentage of water.
In April this year (2015), a paper was published that suggested there might be (transient) liquid water below the surface of Mars at Gale crater, according to readings from the Mars Science Laboratory.
For years spacecraft orbiting Mars have sent back images showing valleys, streaks, and gullies on Mars – they all looked like water was causing them, but there was no proof. Around four years ago scientists discovered features that they have named “recurring slope linnea”, which change with the seasons and temperature. These recurring slope linnea (RSL) – basically large streaks like you might expect to see if water was running down a mountain say – can be hundreds of metres long.
These “streaks”, pointed to water being the culprit, but “there had been no evidence of water” says Dr Michael Meyer, lead scientist for NASA’s Mars Exploration Program – who pauses for dramatic effect – “..until now”.
An instrument called CRISM (Compact Reconnaissance Imaging Spectrometer for Mars), on the Mars Reconnaissance Orbiter, has been used to analyse the chemistry of the streaks when they appear, and the results of this analysis are what is causing the current excitement.
There were two ways the scientists could confirm that the RSL are formed by liquid water. The first would be to use the spectrometer to detect liquid water absorptions on the surface, and the second would involve the detection of hydrated salts precipitated from that water.
The results published yesterday show the presence of hydrated perchlorate salts in the RSL regions, thus indicating the presence of water – though even when liquid it would be more of a salty mix than something you’d get from the tap!
We know that Mars has undergone some huge changes in its lifetime. Around three billion years ago it is believed that perhaps as much as two-thirds of the northern hemisphere of the planet was ocean, but Mars suffered a major climate change event and lost its surface water. The rovers that we have sent to Mars are finding a lot more humidity in the air than expected, and the soils are moist and hydrated.
The preferred theory revolves around the idea of “deliquescence” (yeah, I had to look that one up too). What this means is that the perchlorate salts, which are found on Mars, like to absorb water – so much water in fact that they can at certain times (e.g. when it’s warm enough) become a liquid solution, which trickles down crater walls and other slopes creating the RSL we observe. Perchlorate salts lower the freezing temperature of water by the way.
Other ideas that have been put forth are that the water could come from surface or sub-surface ice melting, or local aquifers. It could be that there are different mechanisms at different locations around Mars.
We often hear the mantra “follow the water”, and so of course finding liquid water is exciting, but as with most science, it’s usually a bit more complex than “found water, will find life”. I turned to Mars expert and NASA astrobiologist Dr Chris McKay to gauge how excited we should be – after all it was his passion for this stuff that got me involved in space in the first place. If this research was as big a deal as the newspapers would have us believe, he’d definitely be excited…
“All life on Earth needs liquid water to grow or reproduce. Life can be dormant in the dry state” he says. “Brines of sodium chloride (normal salt) are suitable for life even at complete saturation of that salt at -20ºC” – that means life can survive in really salty conditions, and studying extremophiles (organisms that can live in extreme conditions) as Dr McKay does, is a good way of understanding the limits of life.
He goes on: “However there are brines on Earth that are too salty for life. The most famous is Don Juan Pond in Antarctica. This is the saltiest liquid water on Earth and is composed of saturated calcium chloride. Nothing can live in the brine of Don Juan Pond.”
“The “liquid water” discovered on Mars is brine, and is a saturated solution of a salt known as perchlorate. This brine is even saltier than the calcium chloride brine in Don Juan Pond.”
Back to Dr McKay: “Such a brine is not suitable for life and is of no interest for biology. The result is of interest only geologically.”
Hmm. So basically, while this is fascinating research all the same, the “water” found on Mars is so salty it probably couldn’t sustain life (as we know it) – and even the Nature Geosciences paper says that: “If RSL are indeed formed as a result of deliquescence of perchlorate salts, they might provide transiently wet conditions near surface on Mars, although the water activity in perchlorate solutions may be too low to support known terrestrial life”.
I guess we best keep on searching then, and take those headlines with a pinch of (perchlorate) salt, eh?