Securing the survival of humanity is just one of several reasons why NASA should focus on sending people to Mars. The trouble is, the space agency will find it tough to afford the trip.

That’s the conclusion of a sweeping review of the value of the US human space flight programme released today by the National Academy of Sciences. Suggested solutions include practice trips to an asteroid to test Mars technology, and increased collaboration with international partners – most importantly China.

According to the report, a human space flight programme is not just important for technological innovation. It is also vital for the long-term survival of humanity, acting as an escape rope in case of a catastrophe on Earth. Having an inspirational goal – such as Mars – is key because then setbacks or accidents in a particular mission are less likely to derail the broader scheme.

However, the report cautions that a human Mars mission won’t happen unless NASA’s budget increases substantially and the government makes a long-lasting commitment to the plan. Achieving those goals could be tough because the benefits of space flight are hard to demonstrate and public support for human missions is modest.

Here are the report’s main recommendations for how NASA can one day put human boots on Mars:

Lasso an asteroid
The panel says that the US should start with trips to closer destinations such as the moon or an asteroid. These would serve as test beds for the technologies and techniques required for a mission further afield. An existing plan to lasso an asteroid and drag it into orbit around the moon could fit in with this, while the Obama administration has championed a “stepping stone” approach to reaching Mars.

Go international
International collaboration could help offset costs, but one problem is that most of NASA’s traditional partners, such as Russia or the European Space Agency, have their sights set on the moon at the moment. If the US wanted to align its short-term goals with potential partners, another possible path would be to build a moon base as a stepping stone to Mars.

Play nice with China
Since sending up its first astronaut in 2003, China has been steadily advancing its space capabilities. Most recently, it put a robotic lander on the moon and has been conducting tests on Earth looking into ways astronauts could grow their own food for long-term missions. Ultimately, it has plans to build its own rival to the International Space Station.

The problem is that, for now, US law prohibits NASA from working on joint projects with China due to national security concerns. The report argues that, considering China’s rapid advances in space, the US is missing out on opportunities to pool resources for a potential Mars mission. Meanwhile, China has given indications that it is interested in partnerships with other governments – and it will move ahead with or without the United States.

Keep SpaceX sweet
The US should also keep working with its private partners, such as SpaceX and Orbital Sciences, when looking to maintain human space flight in orbit around Earth. But the panel is not convinced that the SpaceX Falcon Heavy rocket, which is being developed to ferry astronauts to the ISS, will be powerful enough to send humans to Mars. Instead future Mars missions will rely on the Space Launch System, NASA’s next-generation rocket.

The report makes no mention of Inspiration Mars, a daring plan from multi-millionaire Dennis Tito to send two people on a fly-by of Mars. Although the mission was originally intended to be privately funded, Tito testified in Congress that it could only succeed with NASA’s help, because the Space Launch System would be a necessary part of their proposed Mars shot.

Dragon has once again spread its wings. Today commercial spaceflight firm SpaceX successfully launched its third cargo mission to the International Space Station (ISS), sending a Dragon capsule loaded with just over 2 tonnes of supplies and science experiments.

The capsule lifted off aboard a Falcon 9 rocket from Cape Canaveral in Florida at 3.25 pm local time. It is slated to dock with the ISS on Sunday and deliver the equipment and experiments, including a , a collapsible garden and microbes brushed off a Tyrannosaurus rex fossil.

Following the launch, part of the rocket was also supposed to fire engines as it fell back to Earth and deploy a set of experimental landing legs, which could one day enable rockets to be reused. The rocket should have attempted a mock landing over the Atlantic Ocean, but weather may have complicated the effort.

Sea legs

“The rocket flight on the way up was perfect, as far as we could tell,” SpaceX founder Elon Musk said during a press briefing. But the seas were very rough in the Atlantic, with reports of high waves, and Musk thinks this could have affected the landing. “It was very heavy seas, so I wouldn’t give high odds that the rocket was able to splash down successfully.”

Currently, the rockets that send cargo and crew to the ISS are discarded. A rocket that can return to Earth and safely touch down for reuse could lower the cost of spacecraft by a factor of 100, according to Musk. A version of the system could also bring astronauts back from Mars.

A member of SpaceX’s launch team reports that the rocket reignited its engines after it separated from the spacecraft, stabilising it and slowing it enough to survive re-entering Earth’s atmosphere. The team was recording video of the rocket as it came down over the ocean and should know soon whether the landing legs deployed.

No matter what happened, the experiment shows that having landing legs on the rocket didn’t affect its flight. “We were able to show on ascent that the legs don’t have a negative impact on the rocket,” says Musk. “Even though we probably won’t get the stage back, we’re starting to connect the dots about what’s needed.”

Astronaut garden

And even if the test landing went badly, a robot on the ISS will still get its own boost. Among the supplies and experiments aboard Dragon is a pair of legs for the humanoid robot Robonaut 2, which has been lending a hand to astronauts since the final space shuttle mission in 2011. Until those legs arrive, it will just be a torso.

When it docks to the ISS, Dragon will also deliver the , or Veggie, a plant growth chamber that will test how well red romaine lettuce seedlings sprout in space.

The chamber collapses for easy storage during flight and extends to create a “garden” that is about 29 centimetres wide by 37 centimetres deep – the largest plant chamber in space to date. The hope is that such chambers could be used to grow food on longer deep-space missions, or to provide astronauts with some recreational gardening.

Dragon’s science haul also includes microbe samples from , which asked people to collect and identify microbes in public spaces such as sports stadiums and museums. Cultures will be grown on Earth and on the ISS to compare how low gravity influences the organisms.

The 48 samples selected to head to the ISS include microbes found on at the Field Museum in Chicago and on John Glenn’s Mercury space capsule, , at the Smithsonian’s National Air and Space Museum in Washington, DC.

Original article, published 18 March 2014

The people of New York City may be used to feeling at the centre of the world – and this week their city is at the nucleus of the latest asteroid hunt.

New Yorkers don’t need to panic: the 72-kilometre-wide asteroid Erigone isn’t going to smash into the city. Instead, it is scheduled to eclipse Regulus – the brightest star in the constellation Leo – as seen from the Big Apple, plus a large part of upstate New York and parts of New Jersey, Connecticut, Ontario and Bermuda.

Distant Erigone orbits the sun between Mars and Jupiter. If its predicted path is correct, the star will completely vanish for up to 14 seconds at about 0200 local time on 20 March. And the occultation should be visible to the naked eye, even through the bright lights of Manhattan.

Asteroid occultations are a common astronomy tool, though such events are usually only seen with a telescope and from dark corners of the globe. The International Occultation Timing Association (IOTA) is exploiting the fact that this one is . Its vice president for planetary occultation services, Brad Timerson, gave us the scoop on what this week’s crossing will do for science, the possibility of seeing an asteroid “moon” and a peek into the life of an occultation timer.

What is the appeal of being a volunteer occultation timer?
Seeing an occultation is pretty exciting. At that moment, you realise that the predictions made were accurate and that you have a chance to add to astronomical knowledge.

How often do you get to see an occultation?
involving stars that are visible with naked eyes or amateur equipment occur several times each night. However, the paths are quite narrow and don’t always pass near many observers. I typically observe 15 to 20 events per year, of which three to four actually produce an occultation. The other events are “misses”, which are still quite useful.

Wait, how is not seeing anything helpful?
After an occultation, we create a diagram of the [asteroid’s] path that includes . Each chord represents a slice of the asteroid as seen from different locations. If you are in the predicted path and don’t see the star vanish, your chord can help put constraints on the size of the asteroid. People elsewhere who do see the occultation will see the star blocked out for slightly different times. With enough chords, you can create a of an asteroid that can constrain its size, shape and location.

What are you hoping to learn from the Regulus event?
Regulus is a multi-star system, and the brightest star outshines its dim companion. It is possible that while the bright star is being blocked by the asteroid, we will get a glimpse of its companion star for a very brief time. That will help us learn its brightness and location in orbit around Regulus. Also, the asteroid Erigone may have its own satellites. Many asteroids that are large enough are known to have satellites, and they have been found before using occultations. It will not be an easy observation to find a satellite for Erigone, since we don’t know if one exists and therefore have no idea where to look. We can only say that it is likely to be within about 10 times the asteroid’s diameter and is likely to be pretty small.

So if I am in New York City, where should I go to see the occultation?
You can be any place that has a clear view of the south-western skies. You are going to have to get away from buildings, in places like Central Park or the riverfront – any place with a clear view of the sky about half way up from the horizon.

How can I help with the science?
We created a that will record your time and your location using GPS. Then you just press a button when you see the star vanish and press it again when it reappears, and it will send us your data. We hope the high density of observers will give us a good look at the size and shape of this asteroid – although if you haven’t had a lot of practice, seeing a star vanish can take people by surprise, so there is a delay factor involved.

Will people throw occultation parties?
One of the astronomy clubs in New York City is going to be having an observing party at a location along the river. That will be interesting for people to gather and see the event happen, but it is not that useful scientifically. You need people in lots of different locations to get enough chords. Occultation timers are kind of loners in that regard. We have to space ourselves out.

Thankfully, Luca Parmitano, who was outside the International Space Station when he reported feeling water on the back of his head, abandoned the spacewalk in time and made it back inside. NASA now says the likely cause of the leak was that a water-separation pump became clogged, causing water to back up and flow into the suit’s air vents – something its engineers had not anticipated.

The agency also revealed that the same suit had leaked only days before. At the time it was put down to a minor problem with the suit’s bag of drinking water, one that posed no barrier to the suit being used again by Parmitano.

The malfunction highlights the complexity of spacesuits, which are much, much more than souped-up clothing. The has been in use for 35 years, but now space garb may be on the brink of a transformation. From NASA “suitports” to designs from emerging commercial players, we bring you three things that look set to transform spacewear.

Suitport: Just jump in and spacewalk
(Image: NASA)

Taking into account other cases of spacesuit glitches, NASA is currently honing its next-generation suits, called . The focus of the first prototype – the Z-1 (above) – is easy dressing and undressing.

Existing suits have soft legs and a hard fibreglass upper body, which are tough to put on and take off. Rather than being worn on and pressurised inside a spacecraft, the Z-1 would be mounted to the outside of the craft. Astronauts would simply slide through a hatch into the back of the Z-1, then close the hatch behind them and spacewalk away.

The technology that makes the Z-1’s “suitport” possible also shortens the time it takes for an astronaut to get used to breathing the purer air inside. That means astronauts can more quickly be suited up and ready to explore. De-suiting is also easy: returning explorers would self-dock with the craft and slip back out – especially helpful if things go wrong during a spacewalk, as they did for Parmitano.

Sadly, the suitport won’t be headed to the ISS any time soon, as you would have to change the configuration of the station’s airlocks to use it, says Philip Spampinato at ILC Dover in Frederica, Delaware, the company working on the Z series for NASA. The Z series is a kind of testbed for several concepts that are being developed in parallel. The first sample of the next in the series, the Z-2, should be delivered to NASA by the end of 2014, says Spampinato. A flight-ready suit won’t be ready until 2020 at the earliest.

Indoor suit: Skin me up, Scotty
(Image: NASA-Waldie)

Spacesuits aren’t just for spacewalks: they can also help astronauts inside the ISS. Next year the space station should welcome its first “skinsuit” – a sleek spandex affair that looks something like a futuristic wetsuit. Named the (above), it was designed by researchers at the Massachusetts Institute of Technology, with the support of the European Space Agency.

The skinsuit is meant to squeeze an astronaut to create pressure, mimicking the way Earth’s gravity affects the body. The idea is that wearing the suit should counterbalance some of the effects of weightlessness, such as muscle loss and weakening bones.

Researchers at MIT and King’s College London have worked on various iterations of such a suit for a decade, and one is finally close to going into space. Danish astronaut when he heads for the ISS in September 2015.

Commercial outfitters: watch this space

We all know that these days, government agencies aren’t the only game in space, so will private enterprise shake up spacesuit technology just as it could revolutionise space flight and exploration?

ILC Dover is hoping to share its spacesuit smarts with commercial firms vying to launch astronauts into space, either as tourists or to do work on board space-shuttle replacements, on behalf of NASA. These companies’ plans do not include spacewalks, at least in the short-term, so their suit specifications are different. “The commercial guys are only looking for suits that stay inside the vehicle. All they are doing is carrying people up and down, so that’s a different beast,” says Spampinato.

Commercial space-flight firm SpaceX plans to send astronauts to the ISS using a modified version of its Dragon capsule, which already ferries supplies there. The firm . Spokesperson Hannah Post confirmed the company is developing its own suit, but says it is not ready to share details.

Clarification: Since this article was first published on 27 February 2014, it has been updated to recognise the role of King’s College London in developing the Gravity Loading Countermeasure Skinsuit.

Mount Vesuvius looms large in the story of Pompeii – but the temples of the ill-fated Roman town might have looked to loftier bodies. A preliminary survey of 11 temples in the ruins found evidence that at least nine were aligned with the rising of particular stars or with the position of the sun or moon on days of cultural significance.

If confirmed, the discovery could offer a unique perspective on the blending of religions in the heyday of the Roman Empire.

Pompeii had been a Greek and Phoenician port of call for hundreds of years before it fell under Roman rule in 80 BC. Buried under volcanic ash from Vesuvius’s major eruption in AD 79, Pompeii’s well-preserved ruins are famed for the insight they provide into Roman life.

of research agency Astro-Archaeology Surveys in Guilford, Connecticut, is interested in the way that this insight sometimes contradicts known Roman texts. For instance, a Roman architectural principle states that sacred sites should face west, but not all of Pompeii’s temples do so – perhaps because temples in coastal towns were built according to other religious principles.

Ancient sailors

“Back then you had lots of mixtures of cultures trading by sea, and lots of temples at harbour ports like Pompeii,” says Tiede. “There are really only two things those ancient sailors liked to do when they landed: first they’d visit a house of ill repute and get something to eat, then they’d visit the temples to pray for fair winds. Then they’re off again. So Pompeii is a microcosm of what’s going on in the Mediterranean at that time.” You can compare lots of religious traditions in temple architecture, all in one town, he says.

To see if heavenly objects played a role in temple orientation at Pompeii, Tiede combined digital elevation models, satellite images, ground surveys and maps of the past positions of stars. In work presented last week at a in National Harbor, Maryland, he showed that most of the temples have potential links to celestial objects important in Greek, Roman and Egyptian mythology.

For instance, in Greek and Roman myth, the hunter Orion was killed by a scorpion. The constellations Orion and Scorpius both dip below the horizon and then reappear in the sky during opposing seasons and so seem to chase each other across the heavens. Tiede found that in Pompeii, the Temple of Jupiter is aligned to the first pre-dawn appearance of the star Sargas, the “stinger” of Scorpius, while the Doric Temple faces the first emergence of the star Rigel, which marks Orion’s heel.

Oddly, two Greek temples in Pompeii – those for Apollo and Venus – appear to be aligned with a relatively obscure star called Phact, which has no known importance in Graeco-Roman myth. However, Tiede has uncovered previous work that shows alignments of Phact with at least 12 temples in Thebes for the Egyptian god Amun.

“Greek sailors had been visiting Egypt since the time of Alexander the Great and the founding of the city of Alexandria,” says Tiede. “Afterwards you start to see a fusion, if you like, of Greek and Egyptian religions, including in temple architecture. So you could have Hellenistic temples borrowing architectural rules from colonies in Egypt.”

Scattered stars

Nevertheless, it is too early to attribute any specific significance to these astronomical ties. “Although his approach is serious and technically correct, what he finds is a series of scattered alignments to different stars and moon positions,” says at the Polytechnic University of Milan, Italy. “It is easy to match stars with alignments in this way. The situation would be changed if the author could set up a data set of, say, 10 temples of Isis orientated towards the moon during Roman times.”

Other historians say the idea of star alignments in Pompeii is plausible. “I have little doubt that the constellations were important in the siting and arrangement of cults and their rituals,” says Steven Ellis at the University of Cincinnati in Ohio, who has done . And at the Joukowsky Institute for Archaeology and the Ancient World in Rhode Island says that it is possible the builders of at least some pre-Roman temples in Pompeii were taking astronomical influences into account.

Tiede says that the next step is to look for astronomical alignments in other Roman towns, particularly those where cultures mingled, to see if they show similar evidence. If he is right, the famed lost city of Pompeii could give us fresh perspective on ancient Rome’s cultural melting pot.

“This is not just about celestial mechanics and mathematics,” says Tiede. “It’s a way to track the cultural exchange of people by sea from point to point.”

Astronomers first spotted the cloud, called G2, in 2011 and determined that it will skim unusually close to the black hole’s maw. Originally it looked like the cloud would make its closest approach in September 2013, spurring excitement over the possibility of getting our first good look at our black hole’s feeding habits.

This could help solve a number of puzzles. Seeing the black hole eat would give us a close-up view of how matter reacts to extreme gravitational fields, perhaps offering clues to physics beyond Einstein’s relativity. We could also learn more about how black holes grow to supermassive sizes.

“Black holes need to grow, and we think they grow by accreting mass,” Leo Meyer at the University of California, Los Angeles (UCLA), said today at a meeting of the in Maryland. “This is potentially an experiment where we can watch in nearly real time how this material falls into a black hole. This is a fundamental process that is not well understood.”

But monitoring efforts searching for bright X-rays and radio signals – signs of active feeding – have so far come up empty, in part because the cloud has not actually made its closest approach. Updated calculations have now shifted the black hole’s dinnertime to March 2014.

Spaghettification

In the meantime, astronomers have been able to track the cloud’s movements in near-infrared images. A series of snapshots taken by the in Chile have revealed that G2 is getting stretched like a lump of by the black hole’s powerful gravity as it creeps closer to its doom.

“It is showing tidal shear and beautiful spaghettification,” says at the Max Planck Institute for Extraterrestrial Physics in Munich, Germany, who presented his team’s at the American Astronomical Society meeting this week. The most recent images show that a trickle of material from the front of the cloud has made it to the black hole’s lips, although it is not enough to spark any significant activity, Gillessen says.

For now it’s anyone’s guess what will happen when the bulk of G2 reaches the black hole. It could be ripped apart without triggering much active feeding. Or the Milky Way’s normally inactive, faint central black hole might consume enough of the cloud’s material to ignite dramatic X-ray flares as matter falling in heats up and spews radiation. Its fate depends in part on what the cloud is made of and where it came from, but that is also a hotly debated topic.

Shrouded star

Some groups argue that it could be a simple gas cloud, says at UCLA. Simulations suggest that a gas cloud would be quickly torn up by the black hole and would rain large amounts of material into it, possibly yielding X-ray fireworks and giving us a clear view of what happens when a black hole eats.

Others think G2 could be a young star obscured by a disc of material left over from its birth, which would make the object much less gassy. That would reduce the black hole’s meal to a snack and reduce the chances of dramatic flares. “It is possible this dietary supplement is really nothing,” says Meyer.

The only way to know for sure will be to see the cloud’s demise in action. Multiple telescopes in space and on the ground are gearing up for the next round of observations, perhaps starting in a few weeks, and theorists continue to model a range of potential outcomes.

“Will there be fireworks? The clear answer has to be: maybe,” says Meyer. “But this is a unique opportunity to learn something new in astrophysics.”

Earth is an extreme world. Of the thousands of confirmed or candidate planets astronomers have discovered in our galaxy, the most common type is a world unlike anything in our solar system: an enigmatic ball of either rock or gas that is bigger than Earth, but smaller than Neptune.

That’s according to two independent analyses of data from NASA’s , which spent four years hunting for small planets beyond our solar system. The result narrows down the number of known worlds that can be true Earth twins – and which therefore might host tech-savvy land-dwellers akin to humans.

Kepler discovered planets by watching their host stars’ light dim slightly when those planets crossed in front of them. This method reveals a planet’s size, but not its mass – and astronomers need to know both to calculate a planet’s density – a clue to composition. Knowing what a planet is made of is crucial to determining whether it’s a solid, rocky world like Earth, or a puffy ball of gas more like Neptune or Saturn.

Weighing worlds

The researchers turned to other methods to weigh tens of small planets in Kepler’s cache. A team led by Kepler team member at the University of California, Berkeley, found the masses of 42 small exoplanets by watching how their gravity tugged their host stars to and fro. An independent group led by at Northwestern University in Evanston, Illinois, weighed 60 planets in multi-planet systems by measuring how they pulled on each other.

Both groups found a clear pattern: worlds up to twice the size of Earth are dense and probably rocky, resembling our own planet. Those between two and four times Earth’s width are lighter, so are either wetter or gassy – more like versions of Neptune, which is itself four times Earth’s width.

Looking across Kepler’s entire haul of detections, three-quarters of the worlds it has discovered are of this gassy variety, a planetary type that is not found at all among our eight planets.

“Mini-Neptunes dominate the inventory of 3000-plus planets discovered by Kepler,” Marcy says. He and Lithwick presented their results Monday at a meeting of the (AAS) in Washington DC.

Bucking the trend

The findings fit nicely with theories of planet formation, which suggest that planets above a certain size cannot be made of mostly rock. The more dense material you pile on to a rocky planet, the more it shrinks under its own gravity.

“The theorists have shown very clearly that the gravity of the planet causes it to compress, so you essentially never get planets that are rocky and larger than twice the size of the Earth,” Marcy says. The pattern also implies that the smallest worlds should not be light and covered in gas.

But one freshly discovered exoplanet candidate is already bucking the trend. Also during the AAS meeting, at the Harvard-Smithsonian Center for Astrophysics in Massachusetts presented preliminary data on a planet called KOI-314c (see picture, above). It has the same mass as Earth but is nearly twice the size, which makes it the lightest known exoplanet in Kepler’s catalogue.

Its unusual density hints that the small planet has a rocky core with a gassy atmosphere perhaps hundreds of kilometres thick. “It is nothing like the Earth, because it clearly has a very extended atmosphere,” says Kipping. “That suggests you can’t just draw a line in the sand at two Earth masses. There is a more blurry divide between the two regimes.”

Marcy questions how such a world could have survived. KOI-314c is also very close to its host star, with a year that lasts just 23 Earth days. In such a tight embrace, radiation from the star should quickly strip away its gases, making this potential planet an oddity.

Lucky Earth

Even if the dividing lines are fuzzy, the data still mean that fewer worlds than previously thought have rocky surfaces, limiting our current pool of candidates for an Earth twin.

That may not be bad news for life in general, but it could mean that advanced civilisations are rare. Complex creatures could still evolve and thrive on mini-Neptunes, although they would have better odds on the smallest ones with only a layer of water over the rock. Bigger ones with thick gassy envelopes would have daunting surface pressure, says Marcy. And chances are slim that mini-Neptune life would be very advanced.

“Earth is lucky. If the oceans were two or three times thicker, we’d have no technological life, because how could you build computers in a water world? How could you build a violin, or how could Rembrandt have ever painted in a water world?” Marcy says. “I think there are a lot of planets that have a little more water than the Earth covering the continents. Then you could have microbial life, fish, maybe marine mammals or even birds. But smart, articulate, machine-oriented critters like us humans on a water world? I think it’s unlikely.”

Twenty years after fixing the Hubble Space Telescope by hand, former NASA astronaut Tom Akers believes the trickiest jobs in space still need the human touch

When the Hubble Space Telescope was launched in 1990, a faulty mirror made images blurry. How was it fixed?
The cameras on the telescope were taking data, but nothing was really working right. To fix the problem, NASA discarded a working instrument to free up space to put in the Corrective Optics Space Telescope Axial Replacement (COSTAR). During the fourth spacewalk of the Hubble servicing mission in 1993, we opened up the telescope so my fellow astronaut Kathy Thornton could insert COSTAR, then I tightened the bolts and electrical connections using a big electric drill.

Were you nervous about moving around inside the telescope?
We had exact mock-ups to practise in during underwater training, so it was familiar – except it was obviously real. In the pool you know you aren’t going to hurt anything. During the actual spacewalk you are suddenly cognisant of the need to not accidentally kick things. But after a while you just do as you were trained. Mission control was watching too; if we weren’t doing everything perfectly, they would tell us.

If it was mostly tightening bolts, it sounds as though a robot could have done the job…
After the Columbia shuttle accident [in which seven astronauts died in 2003], I was involved with a team looking at doing a fully robotic repair mission of Hubble. My conclusion was that some simple tasks could be done robotically, but for harder tasks you weren’t going to get there with robots alone. How does a robot know for sure that the wrench is on the bolt? We are now getting smarter physical feedback and feel for robots, but I still think you need that combination of human vision and touch, as well as the ability to react to something you hadn’t planned for.

So will astronauts work more closely with robots on repair missions?
We have already been working that way for a while now. Working on Hubble, we would often have an astronaut perched on the end of a robotic arm. The arm driver could then position the spacewalker perfectly to perform a task, like inserting a part in a bracket. On our missions we had someone controlling the arm, but you could program it to do the same thing robotically.

Isn’t it awkward to be bolted to a robot arm?
Having your feet restrained during a spacewalk is a comfortable job, because you can do whatever you want with the rest of your body. When you are free-floating, every action has a reaction. I can still remember floating up to the bottom of Hubble and getting ready to open the doors. If I grabbed hold of the handrail and squeezed, it would rotate my whole body. So you learn not to grab and squeeze in space.

After 20 years of glorious space images, what is your favourite Hubble picture?
You could have an art show of Hubble images, they are all spectacular. But honestly, I like the first image released after the repair mission: the shot of the spiral galaxy that was blurred . That’s the first image we saw that said, you guys fixed it.

This article appeared in print under the headline “Pass me the wrench”

The moon is laying out the welcome mat. On Saturday, China placed a lander and a rover on the lunar surface, ending a 37-year gap in visits to our closest celestial neighbour. But the Chinese spacecraft won’t be alone for long. A caravan of international and privately funded missions is on the horizon, including several efforts hoping to prospect for resources to aid future human missions.

China had initially said that its °äłó˛ą˛Ô˛µâ€™e-3 spacecraft would end up in the moon’s Bay of Rainbows. But the actual site it will explore may be even more interesting scientifically. As seen on the image above, the °äłó˛ą˛Ô˛µâ€™e-3 lander touched down in a dark plain called the Sea of Rains, which is on the far eastern edge of its targeted landing area.

This vast volcanic plain appears to contain , as well as rocks ejected by impacts that could be parts of the buried lunar crust. Armed with cameras, a spectrometer and ground-penetrating radar, the mission’s Yutu, or Jade Rabbit, rover might help to piece together the moon’s volcanic history.

India, Japan and South Korea also have plans to send landers and rovers to explore the moon in the next few years, although they have not yet stated their destinations. Meanwhile, the US, Russia and several private ventures hope to reach the moon’s poles by 2018. Orbital data suggest that the polar rocks and craters are filled with water ice, which could be harvested for astronaut hydration, radiation shielding and even rocket fuel. If moon mining plans come to fruition, future lunar outposts could become rest stops for missions headed to Mars and beyond.

(Image: Patrick Hickey)

Spores drift through a dark wonderland, carried on the breath of a weeping toadstool to destinations unknown. This psychedelic scene is the work of a toxic Amanita muscaria mushroom, commonly called the , viewed up close as part of a study on how fungi spread their spores by making their own wind.

Previous work showed that cup-shaped fungi such as cottony mould and morels stir a breeze by simultaneously ejecting spores from thousands of cells. The resulting puffs of air carry the fungal seed much further than if it had been simply dropped.

But capped mushrooms such as fly agaric, oysters and shiitakes (below) instead make their own weather to loft their spores, says Emilie Dressaire at Trinity College in Hartford, Connecticut. These fungi release water vapour, which cools the nearby air and creates localised convection. Speaking at a , Pennsylvania, Dressaire suggested that many mushroom species might use water to make wind. It seems that the more we learn about mushrooms, the curiouser and curiouser they become.

As a laser beam illuminates a shiitake, an air current disperses the spores (Image: Emilie Dressaire & Marcus Roper)