Thursday, 2 July 2015

What have Rosetta and Philae told us about comet 67P?

What we can learn from a comets acne:

The unfolding story of the Rossetta mission - and its comet lander robot Philae - is one of the big real-life 'to boldly go' dramas of recent times: The mission has swung from triumph to near disaster and back again, with the mothership taking amazing close up pictures before being force into deep space by the increasingly dangerous comets activity, the lander being the first human craft to land on a comet before being lost in the comets valleys for seven months and then dramatically returning.

Even the Starship Enterprise was actually supposed to explore the universe. Yep, pay attention and there's, like, fifteen whole seconds of that every episode before the space babes and Kirk vs lizard fistfights break out...
But ESA didn't actually send Rosetta and Philae to 67-P to get into hi-jinx. They sent them to learn about the comet - and that's what they've been doing. The most recent science release is about the pits that dot the surface of 67-P and other comets. The pits have been a tantalising mystery for as long as they've been known: On most worlds they'd be the result of impact with other objects, but comet surfaces are much to fast changing for that. They could be the result of pressure build up as gas build below the surface, but when the Rosetta team actually observed an explosive outgassing event it didn't remove anywhere near enough material.
Above: An ESA infographic on the pit Rosetta has been studying.
So what is behind the devastating acne of comets?
It looks like they're distant cousins to terrestrial sinkholes, and this tells us some unexpected things about how the inside of the comet is put together:
The pits range in size from around ten meters to over two hundred, and some are over two hundred meters deep. Their sides are lined with fractures, out of which the evaporating gasses from the interior gush. There are currently eighteen pits of interest on he comes surface, at various stages of growth, and they appear to tell the same story: The pits begin as vents, which are powered by evaporating ices n the subsurface. Over time the evaporation hollows out a cavern beneath the vent, and eventually the roof collapses, revealing a pit. Now the pit itself is exposed to the sunlight the erosion begins to move back from the pit walls, leaving a steep and jagged edge to the pit. Eventually the volatiles within reach of the surface are depleted, and the vent reaches a more gentle shape, and shuts down


So that's one mystery (tentatively solved) But what else has Rosetta told us so far? Here're just a few of the results released so far:


Meanwhile, at Ceres...

Everyone is still scratching their heads. The bright spots on the surface, the one's that are visible from Earth? Yeah, we still can't work those out. And, as well as bright spots which no one can work out....
Above: The Cerean bright spots, shown as a morph from the sun being high in their sky to the Sun being low in their sky. Courtesy of unmanned spaceflight.com
...the dwarf planet Ceres has a pyramid shaped mountain, striped with white, that no-one understands either:
Above: The mysterious mountain/pyramid. It might be the cebntral peak of a masive impact crater.... but an impact that bg would be close to the size needed to shatter Ceres to rubble...

Monday, 29 June 2015

DARPA plans to use microbes to change the solar system

A step towards terraforming?

Technology is usually a double edged sword, which is why a news story I've come across this morning has left me with a particularly mixed collection of emotions: The American Defence Advanced Research Projects Agency is working towards developing designer micro-organisms, engineered to slowly change the surface environment of the planet Mars to some thing more habitable.

That would be a huge achievement, and Mars is a prime target for terraforming: Mars is in many ways already similar to Earth, and there's plenty of evidence that it may have been intermittently more habitable in the past -  it is just suffering a very severe case of climate shift currently. To my mind, IF we can be sure we aren't destroying tracers of native Martian life, past or present, then there's no reason to keep Mars in its current state if we can change it - but for the foreseeable future, we can't be sure of that. And, I'm sure, a lot of people will see the magnificent Martian wilderness as being worth keeping around for its own sake.

Yes, it is beautiful - but think how much more beautiful it would be with just one plant growing on that soil.... Courtesy of NASA 
However, let's try and  look at this from a slightly 'big picture' perspective, as the scientific and engineering community has been making quiet rumbling noises about the possibilities of genetically engineered organisms in space for a while now.

Engineered for space:

While dropping microbes onto Mars is going to be controversial - especially given that that might destroy or obscure any evidence as to whether or not Mars ever had native life - the 'Living Foundry' project, which is where this has come from, is about a good deal more than that. Some of the most interesting, and non controversial, applications of engineered microbes in space are aimed at the asteroids and comets - tiny worlds that we could quickly explore and know, and then be ready to change

Above: A 50 km wide asteroid, 253 Mathilde. Is that 50 km of rock, 50 km of fertiliser, or 50 km f microbe food and rare metals? Courtesy of ESA.
If water and warmth are present then it doesn't look like huge modifications will be needed to the microbes: Some micro-organisms have been shown to be happier living on asteroid soil than on terrestrial soil. On top of that a recent study showed that the material making up C-type asteroids is extremely fertile, and could be ideal for growing crops if a way could be found to keep the asteroid supplied with atmosphere - perhaps a section of the asteroid could be 'roofed over', an idea known as parraterraforming.
Above: A particle of asteroid dust, being eaten by ,microbes called Metallosphaera sedula
If growing crops on an asteroid sounds like a strange idea then you may find this one even stranger: A company called Deep Space Industries has a plan to inject life supporting liquids into the subsurface of an asteroid - not to grow crops, but to grow bacteria, which would be engineered to munch on the asteroid and leave behind processed metals and other useful chemicals.
The idea has been looked at before, and would need none of the massive engineering development costs incurred by mining asteroids in a more 'conventioanl' way - IE with large chunks of machinery, manned spacecraft, and new technologies which need to be hauled into deep space. DSI's plan could be pulled off with a modest sized space probe and a handful of cubesats. And the idea of mining with bacteria isn't a new thing either: Ores here on Earth are already processed using microbes. 

Above: A heap bioleaching site, extracting copper using microbes. Courtesy of Mining Technology magazine.
Engineering organisms to re-shape the solar system might be controversial in some areas. But in others it seems like it might be a logical extension of the recent drive towards miniaturisation -  perhaps deep space mining ships won't be like the oil rigs of today, massive vessels crewed by hundreds of people, but table sized machines, crewed by microbes with a taste for asteroid dust. So, for the moment, i won't be getting too excited about DARPA's research into how to use microbes to change mars - I'm not the biggest fan, but the same technology could give us the ability to start using the solar system in ways we've previously only dreamed of..
Above: the massive (fictional) mining ship Red Dwarf -  but right now it looks like space mining ships could be much, much smaller. Courtesy of DrWhoOne on deviantart.com
Dragon spacecraft lost in explosion

Dragon spacecraft lost:
SpaceX's most recent attempt to launch their Dragon spacecraft towards the ISS has resulted in an unexpected disaster: the craft has been lost in an explosion, just before the first stage booster separated. It's not clear what caused the explosion, but supplies, research experiments, and a number of cubesat space craft (due to be launched from the station) were destroyed.

At present it isn't clear what caused the explosion, after several thousand man hours of reviewing the data. Elon Muck has tweeted that his team are now trying to recover the last few milliseconds of data, for any clues. ESA Director General Jean-Jacques Dordain offered SpaceX the following message of condolence and support:

"We at the European Space Agency deeply regret this failure that shows that sending launchers into space is a very hard job. However a failure does not undermine all the previous successes. We wish our colleagues on the other side of the ocean all our best in fixing the problem and getting back into flight again soon". 

One online forum has even started a 'Best wishes to SpaceX' thread!

Elsewhere on the internet:

Giant black holes soon to be imaged
Student experiments fly into space

Sunday, 28 June 2015

Black holes are bad - but black strings could revolutionise physics....

Note: I'm getting married in under a month, so, to keep posting while full blown wedding prep goes into operation, I'm going to be focusing more on simplicity and single stories.

How we might see inside a black hole

What's worse than a black hole? Ok, yes, you could be sitting on the toilet when an angry dwarf bursts in with a crossbow an accuses you of sleeping with his girlfriend:

Oh, thank you HBO for giving me not just a picture, but a video clip to go with that line!

But, aside from that, what's worse than a black hole? Lots of them of course! A cluster of black holes may just sound like something a physicist was making to scare his kids, but there are theories of physics - theories involving space having hidden extra dimensions - that would make it possible for there to be massive strings of black holes floating through the universe.

Above: Professor Farnsworth is the man to tackle this. Better him than me.
The phenomena that could give rise to this is called 'black string': Imagine a tower, made of black holes stacked one on top of the other, stretching through the universe, slicing through whole galaxies like razor wire - that's a black string. Such a thing can exist in theory, although no-one can guess how one might form. Now, a number of questions might pop into your head if you actually encountered one of thee things, such as  'how do we escape this thing' and 'who thought it was a good idea to make a last minute bargain space tourism booking with a guy called 'The Doctor'? But the question that Roberto Emprani, of the Instituci o Catalana de Recerca i Estudis Avancats asked was: If something makes this thing vibrate, what happens to it?

Above: If you're thinking that Roberto's question is on par with asking 'what happens if I try to re-wire the big red doomsday button', you'd probably be right.
Roberto clearly has an interest in finding the answers to such terrifying scenarios of cosmic disaster, because he and his companions have developed a series of equations to find the answer: The slightest vibration causes the string to collapse into a long ribbon of black holes, joined by short necks - like a cosmic necklace of black, sucking, pearls (here's the paper). OK, that just sounds like terrifying cosmic death in a slightly different configuration, and it is, but it might - might - point the way to the of holy grail of physics: How to see inside a black hole.

Above: A quick spot by Greenwich Museums, explaining hat our theories predict could be inside a black hole.

How so and why do we care? A black string can be thought of as being a very elongated black hole, and like a black hole it has an infinitlydense singularity in the middle where all the laws of physics break down, safely cut off from the rest of our universe by an vent horizon - an impassable one-way barrier. If a string is made to vibrate, and collapses into individual black holes, the event horizon can briefly vanish along parts of its length, exposing the singularity.

If you've seen the movie 'interstellar' then you'll know that being able take data from an exposed singularity would let us unify general relativity and quantum mechanics, possibly opening the doors to faster than light travel, time travel, and a political systems that only promote honest, trustworthy politicians*.

Could this all actually happen? According to some theories our universe has more dimensions than its obvious 3 space plus 1 time. If that's true then all black holes would actually be black strings, just with their long axis oriented along the hidden, folded up, extra dimension so we only see their spherical cross section.
If that's a bit tough to visualise, imagine the good old fashioned 'rubber sheet of space' with the stereotypical gaping pit of a black hole punched through it:
Like this, the old rubber sheet with a weight visual metaphor. Although if you try to actually stretch a real rubber sheet this much you're probably going to put the weight through the ceiling in a moment.
Draw a big circle around the entrance to the hole, to represent the impassable event horizon. Now zoom in on the rubber sheet until you can see the thickness of the sheet. That thickness is the sheet's extra dimension (or extra direction) squashed down small - we exist on the surface of the space-time sheet so we can't sense it, but it's there. If the circle marking the edge of the black hole extends all the way through the sheet then it's actually a very short cylinder - or a very short string.

What if we could inflate the thickness of the sheet, expanding the extra dimensions, so we could see the black hole as a string? Well then we could watch the string collapse, and perhaps see the singularity exposed - if our card tower of theories holds together. Inflating an extra dimension like that is, in theory, possible: That's what happened to our regular 3 space dimensions just after the big bang. So, maybe, just maybe, the impassable barrier around a black hole can be beaten.

The question would then become not if we can, but if we should.....

Elsewhere on the Internet:

Record amounts of antimatter produced

Exposed water ice seen on comet 67-P and here's the paper

Virgin Galactic to launch 39 satellites

The world looks to a reusable rocket future

NASA tests VR for the space station:
 

Laser beamed star ships edge closer to reality - and make deflecting asteroids look more likely

Wednesday, 24 June 2015

Does Europa's ice hold the key to alien life?


Life's building blocks on Europa?
Europa is the second moon out in the Jupiter system of moons, and one of the most fascinating worlds we've come across. Why? Its looks maybe?

Above: Well wouldn't you be curious if you found a scratched pool ball thousands of miles across? Courtesy of NASA.
Not looks then - the gigantic cue ball look is soooo 2007. In one word the real reason is: Water. A world engulfing ocean of it in fact: Beneath Europa's icy surface all the evidence suggests (and there's a lot of it these days) that Europa has a global ocean, maybe hundreds of kilometres deep. The ocean is made from ice kept liquid by the way that Jupiter's gravity constantly kneads the moon's core into volcanic fury, the same process that drives the insanely huge levels of volcanic activity on Europa's neighbour, Io:


 
Above: If you're unclear about what makes Europa soooo interesting this should clear that up for you.
 
This doesn't just make Europa a unique place in our solar system*, it means that Europa has two of the major things needed (we think) for life: Lots of water and an energy source. But what about the all important third thing, organic chemistry? Well researchers from the  Earth-Life Science Institute, Tokyo Institute of Technology, may have found a way that the right chemical ingredients can make their way into Europa's ocean: C-type asteroids, and comets, are known to contain the basic chemical building blocks of life, such a nucleobases and amino aids.These are thought to have been formed in the interstellar dust clouds that preceded our solar system, and in the warm subsurface of protoplanets. Over time fragments of these protoplanets and comets would have rained onto Europa's ice... but that isn't enough to start life. 
Above: Comets like 67-P here might be the source of life's building blocks - one of the goals of the Rosetta mission is to find that out -, but what makes those blocks come together? Courtesy of ESA.
What the Tokyo team have found is that the simple organic chemicals buried in the cold ice near Europa's surface will polymerise - which means join together to form more complex molecules. Over time these more complex molecules will be drawn into the ocean by the movement of the ice, and we know from lab experiments here on Earth that when molecules like these are mixed with water they can start to form life-like structures that do things like reproduce and adapt to their environment.

Does all this actually add up to life?
We don't know, but we're going to find out a lot more about Jupiter and Europa in the next decade or two: The JUNO mission will arrive at Jupiter to study the giant planet itself in almost exactly a year, and NASA is launching a dedicated mission just to study Europa itself in the 2020's. Here's a (40 minute long or so) video on the decision and the mission, from NASA:


 
Above: NASA announce that it intends to send a probe to Europa. About time! Courtesy of NASA.

For now though, the Tokyo team will have to content themselves with lab experiments and simulations. But someday soon they'll get to find out, from Europa itself, how close to the mark their research is. Their paper is here.

Elsewhere in the Universe:

A solar storm violent enough to produce the rare pink Aurora's is unusual. But over the last few days the Earth has been lashed by storms of particles strong enough to produce those aurora so far south they could be seen from the southern cast of England! Of course, here in Scotland it was cloudy..... 

Above: The powerful aurora created by the solar storms this week. Courtesy of Amazing Sky Photography,

Pluto-Charon animation:
As New Horizons gets ready for its date with Pluto in a few weeks the image wizards over on unmannedspaceflight.com have produced this animation, based on the images taken so far:

Above: See how the two worlds swig around each other? That's becuse Charon is so big compared to Pluto that ts gravity forces Pluto to Orbit Charon a bit as well. Courtesy of Fred_76 on unmannedspaceflight.com

* Technically this doesn't even make Europa a unique place, as many icy worlds are suspected to harbour hidden seas and oceans, including Europa's other neighbour Ganymede, Saturn's moon Enceleadus, Pluto's moon Charon and possibly even the dwarf planet Ceres

Elsewhere on the internet:
How the Martian atmosphere changed
Stability of exomoon atmospheres
Going into space to see Earth's core
Ultra dark galaxies
Rosetta mission extended

Monday, 22 June 2015

Have we found the first stars in the universe?

I'll be up front: I had my stag weekend yesterday, and I'm in no fit state for a video. But there're some good space exploration stories anyway - the universe doesn't stop for my sore head!

First stars found?
According to the Big bang theory (and yes, it's still just a theory and always will be, that's science folks) shortly after the universe began it was a soup of hydrogen, helium, and some trace amounts of lithium. Every other chemical element - like, say, all the carbon and oxygen atoms that make up you and me - were cooked up in the cores of stars. That sounds weird, that you were cooked up in a star? Here's how...

Above: The 'can we hurry this along, my tea is burning in the oven' version of nucleosynthesis.  

Here's the long version if you like your nuclear physics*...

Above: The in-detail version of nucelosynthesis.

What this means is that the very earliest stars - generation number 1, also called population 3 for historical reasons - must have been very different beast than the stars we see today: Almost devoid of heavier elements, they would be detectable by spectroscopy today as the most powerful telescopes can see light that has been travelling since that early time. Using the Very Large Telescope of the European Southern Observatory an international collaboration between the Universities of Lisbon, Geneva, California, and Leiden has found what they think might be a clump of these very early stars, nestled in a galaxy in the very early universe (link in the subtitle above to the paper).

To be fair this isn't a confirmed find: They are looking at a galaxy over 13 billion light years away, and 13 billion years into the past, so this is on the limits of what can be done. And the evidence doesn't match up with Pop 3 stars perfectly - the team believes this very young galaxy has waves of star formation moving through it, with the pop 3 stars on the leading edge of the wave and consuming the 'cleanest' gas clouds.

But, if this pans out, our civilisation is now looking at the first lights the universe ever saw....

Venus is (almost certainly) a volcanic world 


Above: Artists impression of  balloon borne probe in Venus' atmosphere. Courtesy of me, and my ego.
Venus is an enigma of a world, and then some: It's chemically complex atmosphere is so dense near the surface that it acts more like an ocean of hot gas than air, and the weather patterns include gigantic double-eyed hurricanes and mysterious UV absorbing chemicals in the clouds. On top of these myteries, Venus' surface is bizarrely young, the whole planet rotates backwards and very slowly, it's mountains are covered in a strange layer of highly radar reflective material, and sometimes the chemical composition of the upper layers of the atmosphere will change abruptly for no obvious reason.
Yet there is a layer of Venus' atmosphere, 70 km above the scalding surface, that is the most Earth like environment we've ever discovered - Earth like pressure and tropical temperatures.

Exploring Venus is, and always has been, a major challenge: That ocean of super-heated gas that covers the surface cooks landers in hours. Balloon probes have floated through the atmosphere, before the winds drew them down to the crushing depths. But now, thanks to the (now destroyed) Venus Express mission by ESA, Venus has given up a crucial secret: It is a world with active lava flows.
Above: A Venusian mountain. Not pretty, but neither would you be under 90 atmospheres of red hot CO2. Courtesy of NASA.
The Venus Express team have found spots resembling lava flows on the surface, near the mountains Maat Mons and Ozza Mons. Now they have revealed that these spots are first getting much hotter and then cooling again over a matter of days.
This is a pretty strog indicator that the flows are still active in some way, and it begins to unravel some of Venus' mysteries: Active lava flows means active volcanoes - which mean that there are new chemicals being blown into the atmosphere by  volcanic plumes and could start to explain the odd chemical changes in Venus' atmosphere, and ongoing lava flows could also explain why the planets surface is so young - it is young (geologically). A geologically active Venus also makes a more tempting target for future space missions, so here's hoping this inspires a few balloon riding probes in the next few years....

The clearest views of Pluto yet:
The New Horizons probe has obtained its best views of Pluto (and it's largest moon, Charon) ever:

Above: Courtesy of Phil Stooke at unmannedspaceflight.com
Details are definitely starting to emerge, but so much of the most interesting stuff is still tantalisingly hidden just beneath the limits of resolution. If I could go up there and give New Horizons a push I would do (any supermen reading this please considr that a request)...

My unsubstantiated opinion: Will the rise of the nanosat spell doom for manned space exploration?

Above: A cube sat, sitting on someones desk. I don't know whose. That's at least a few tens of thousands of pounds of machine there. I hope they don't have a wobbly desk leg ....
I talk about cubesats as lot here: Cubesats are miniature spacecraft used for research- each basic cubesat is just 10 cm on a side, and weighs only 1.33 kg.... and they've been an amazing hit: This year has sen the launch of the first cubesat with a drive capable of propelling it to another planet (the Planetary societies Lightsail-1), it will also see the first ever interplanetary cubesats (which are hitching a lift to Mars on the back of the MAVEN mission there), and we may also see some of the first launching systems dedicated to cubesats and cubesat sized payloads begin operation. The field of developing cubesats into more than just high tech toys is booming, with novel ice powered engines, new kinds of thruster, and NASA initiatives. We might soon be seeing interplanetary missions for under $10 million thanks to cubesats.

We're also seeing efforts to push the envelope with miniaturisation even further - like the ongoing efforts to develop chipsats: Satellites that are effectively just a sliver of silicon wafer. These postage stamp craft have even been touted as a potential way to build an affordable interstellar probe, using Jupiter's magnetic field as a massive particle accelerator, and deploying a swarm of ultra high speed chipsats this way, in a fashion reminiscent of the 'starwisp' starship design. They've also been put forward as a way of exploring Jupiter's most habitable moon, Europa

Cubesats and other such miniature spacecraft have opened up space to a section of the world that wouldn't otherwise get the opportunity to do more than look to the sky and dream: Less wealthy nations, Small private concerns, colleges and universities have all had the high frontier opened up to them. So will space craft get smaller and smaller? And what will that do to our efforts at space exploration?

Above: A talk on the 'Micro and nano satellite revolution. I assume this means the revolutionary technologies, not a revolution that happens to use nano sats as weapons, dropping out of the sky onto peoples heads. Although I did reinforce my umbrella for a reason.... Courtesy of the National Physical Laboratory. 

In my (very humble) opinion the answer to the first question is both yes and no: We will  - we are already - seeing an increase in the number of nanosat missions. It makes sense, as they allow people with interesting ideas but limited budgets access to space, as well as giving people who want quick to develop and launch missions, like the military, a new avenue (it's no surprise therefore that DARPA are among those developing their own nanosat launcher).

I'm very, very, happy with all of this, but there is a potential downside: A new generation of ultra small unmanned craft means that the demand for the heavy lift rockets needed for manned exploration goes down. That means their price er launch goes up, which makes all manned space exploration more expensive. So will we see the slow death of manned exploration by economy , as the miniaturisation of unmanned space craft makes unmanned exploration much more efficient?

For my money no - there are still missions that will need a big mirrrors, big antenna, bulky power sources, and other things that cannot be miniaturised. Then there's the burgeoning space tourism industry to consider, and the demands it will make. What I expect-  and hope - to see is a diversification: More missions of the smallest sizes, but also at least as many missions of larger sizes. Then there's the economy of scales to consider: it is cheaper to launch many small missions on one bigger heavy lift rocket, than to assign each nanosat its own launch. I can understand the concern of manned spaceflight enthusiasts, but I don't believe the rise of the cubesat will kill off manned spaceflight - it will take another botched and unrealistic attempt to relive Apollo 'glory days' without assigning the needed budget, and the resulting public backlash against wasteful government spending, to do that.

If you're curious, here's the cubesat website,  and here's presentation on upcoming cube sat technologies

Above: Art work showing lightsail-1, the first ever cubesat with an independent space drive that could take it to another planet without assistance. Courtesy of the PlanetarySociety.

*All three of you.

Elsewhere on the Internet:
Chipsats are go!

Titan is dissolving!
Robots with tentacles 
Taking pictures of exoplanets

Wednesday, 17 June 2015

The latest news from Philae and 67-P

The latest news from Philae and 67-P

Above: The bizarre landscape of 67-P.It looks like good hiking country. If you can ignore the lack of air. And gravity. And the way jets of vapour explode out of the ground.A challenging hike, for Superman when he needs to chill perhaps... Courtesy of ESA.
The European Space Agency's 'Philae' comet lander  called home over the weekend, seven months after it disappeared amongst the crags of comet 67-P. The Rosetta - Philae team have been thrown into feverish preparation and planning, to make the most of the washing machine sized robot, now that they have it back. Today they called a press  conference to update the public on where they, Philae, and Rosetta have gotten to:


  
If you haven't got time for the whole thing, here're a few notes:
  • The lander contacted Earth for 85 seconds on Saturday and 4 minutes on Sunday - although the signal on Sunday wasn't stable.
  • Philae has been awake for some days before contact.
  • The lander has 24 watts of power, and an internal temperature of -5 degrees Celsius.
  • The Rosetta mothership will change its course to get better communications with Philae
  • Some low risk, low power, science operations will begin soon.
  • Although the lander is at an odd angle to the surface they will still be trying to get samples of the comet's soil.
  • One panel member thanked the comet itself!
  • Philae probably endured temperatures below -150 degrees Celsius.
  • The landers shaded resting spot will actually protect Philae, and allow it to survive longer.
  • The comet is coated in grains of organic matter, with no ice visible anywhere
  • The organic grains outweigh the ice that is there.
  • The grains coat, and hold together, the ice particles.
  • Much more science to be released in a few weeks.
  • They will be looking for life-forming molecules like amino acids.
  • "If this is a dream I'd rather not wake up!"
While we're on the subject of comets, a paper published this week reports on the analysis of the dust collected from comet Wild 2 by the Deep Impact mission it seems the comet formed near the end of the Solar System's growth, and includes material from across the protoplanetary disk the planets grew from. The paper is here.

Above: Comet Wild 2, which has its own ancient solar system story to tell us. Courtesy of NASA.
The inventive Lightsail-A mission, a tiny spacecraft that successfully tested an experimental propulsion called solar sailing, has re-entered Earth's atmosphere and burned up. Lightsail 1 was a privately built craft, from The Planetary Society. It's successor mission is due to launch next year, and the kickstarter for it is here.
Above: Photographer Thierry Legault captured this video of Lightsail spinning over France, a few days ago.

Does anything live on the edge of a black hole?

Are you dissatisfied withe the view from your bedroom? It could be worse - it seems that there may well be whole solar systems that wake up every morning to a view like this:
Above: A fanciful depiction of an alien city, on a world that orbits the gigantic black hole Saggitarius A*. No 'courtesy of...'', because it's mine.
Y'see it's been a mystery for while why there are so many stars crowding around the massive black hole in the centre of the galaxy -  it's very hard for that many stars to fall into the vicinity of the hole without a lot o them being torn up and pulled in. That would lead to a lot of hot, angrily energetic, gas around the hole, and we just don't see that. But a paper from the Max Planck Institute for Astrophysics has suggested that stars and planets could grow orbiting the central black hole of our galaxy. The clouds of gas and dust that normally give birth to stars and planets can be pulled into a disk orbiting the hole - and stars (with their planets) can then grow in an analogous way to the growth of our own solar systems planets. The evidence for this is in the form of two rings of star growth that surround the hole - there may well be whole solar systems that live in the sight of the most powerful destructive force in our galaxy.

To make life even more interesting for anyone/anything living near the monster hole it regularly fires off x-ray flares that seem to have a similar mechanism behind them to our Sun's solar flares - but big enough to be detectable from tens of thousands of lightyears.
Could there be anything on those worlds to see the looming sight of that gap in space-time over their heads (or whatever they have)?
There's water ice and organics near the Milky way's core black hole according to a new paper, so the ingredients for life's chemistry could be present on any worlds near the black hole. But the radiation environment of the galactic core - lots of hyperactive blue suns, not to mention the gigantic hole itself, would make for a harsh environment.

Pluto emerging for New Horizons:

New Horizons, the space mission that is fast approaching the frigid dwarf planet Pluto (and its complex system of moons) has gotten some of its best images yet of the little world: surface features are starting to emerge - now the challenge is to understand what they are....
Above: The faces of Pluto, courtesy of  Bjorn Jonsson.

People are also starting to turn the images into simple maps, and even virtual globes:

Above: A basic virtual globe of Pluto, Courtesy of Bjorn Jonsson and unmannedspaceflight.com

The National Space Society has also made a truly kick-ass video, celebrating the mission:



DARPA may already be launching cubesat's on its new specialist launcher:

The American Defense Advanced Research Projects agency will soon begin testing it's SABRE launch system. SABRE is a rocket to orbit that launches ultra small cubesat spacecraft from the belly of an F-22 fighter jet. This would give the US the ability to quickly launch hard to detect ultra small satellites for reconnaissance.It is possible that DARPA has already begun launches, in secret.

The next few months are shaping up for some really exciting space exploration....

Elsewhere on the Internet:

Io's lava lakes now visible

Sunscreen layer on distant planet

Computer models suggest ancient Mars was 'cold and damp'

SpaceX looks to beam the internet from space

NASA to launch first interplanetary cubesats

Miniature nuclear power sources for cubesats

China tests hypersonic vehicle

An intro to cosmic strings

Dark matter or modified gravity? Evidence across 12 orders of magnitude

Sunday, 14 June 2015

Philae lives, and Is Jupiter a failed star - or a deuterium burning brown dwarf?





 

Philae lives!
Update: I've heard that this morning CNES director Mr Le Gall reported a second contact from Philae.

Seven months ago the European Space Agency made an a attempt to drop a robotic lander onto a comet. It's mission was to analyse samples of the comet, looking for molecules that might have contributed to the formation of our solar system and the origin of life. It worked...ish. The various mechanisms meant the secure the little probe, called 'Philae' to the comet's surface didn't work as planned, the lander bounced off the surface, did a sort of long 'hop', then anlother, and wound up.. somewhere. A spot on the comets surface, at the base of a cliff, on it's side.


Above: One of the last images sent from Philae, showing the bizzare texture of the comets material. Courtesy of ESA.
Now, this wasn't a disaster by itself, but the combination of the landers angle and the shadow of the cliff made it impossible to get any sunlight, and so it was impossible for the solar poanels to recharge the landers batteries. Attempts to change Philaes position failed, so the team ordered the craft to carry out some basic science, and then the probe went silent.

Above: Comet 67-P. Somewhere on the incredibly tortured landscape the little lander is till fighting the fight to survive. Courtesy of ESA.
Until last night, when the increasing sunlight on the comet finally got bright enough to wake the little robot up, and Philae phoned home. Details are still coming in, but here's what we have heard so far:
  • Philae was in contact with Earth for two minutes
  • It's solar panels are generating around 24 watts of power - a comfortable margin over the 19 watts minimum it needs for two way communication.
  • It isn't where the team thought it would be.
  • Its Twitter account is active again
  • It's internal temperature is a frigid -35 degrees Celsius, but set to rise
All in all great news, and here's hoping the lander is able to continue it's mission. An amazing achievment! If you speak some French, here's a breaking news report...
...and here's a link to the Nature report.

Elsewhere in the Universe:

Does Jupiter burn deuterium?

It's been said a often that Jupiter is a failed star, and like many things that are often said it's almost completely wrong: True, Jupiter has a very star like composition - hydrogen and helium mainly - it is a huge ball of gas just like a star, and its system of moons is very much like a miniature solar system. However if you ask almost any astronomer they will tell you that it is emphatically not a failed star, it's much to small. and it has never shone by nuclear fusion like a star. They'll say the idea that Jupiter could ever be a star is based on the (still very good IMHO) scifi movie 2010:


Real failed stars are known as 'brown dwarfs': These are star like objects in composition, but too small to generate the pressure and heat in their cores that are needed for hydrogen fusion, the process that makes stars shine. They do, however, fuse deuterium - a rarer isotope of hydrogen that can fuse more easily - for a short while in their lives, which makes them glow dimly in the infra red. For this to happen they need to be at least 13 times heavier than Jupiter - because even deuterium needs that much more pressure in a gas-balls core than Jupiter has.

But there's a twist in this tale: Jupiter does, in fact, 'shine' in the infra red, from some unknown heat source. In fact it puts out half again as much heat as it receives from the Sun, and this heat is what drives its terrible storms, like the Great Red Spot. Various mechanisms have been put forward to explain this - residual accretion heat, compression heat, phase changes in the metallic hydrogen ocean thought to make up Jupiter's lower levels.

 
Above: A NASA sciencecast, explaining what we don't know about Jupiter's innards, and why that's important.

But this week a paper has been released from the University of Calgary, that could mix all this thinking up, describing experiments that show that deuterium can fuse at Jupiter-level pressures if it is mixed into a solid core - and a whole bunch of theories on Jupiter's formation predict that it should have a solid core, deep, deep down. In fact, the debate about whether or not old Jove has a solid core is part of the reason why the JUNO space probe is heading to Jupiter right now.


 
Above: Make yerself a cuppa, and sit down to enjoy a full blown documentary on the JUNO mission to X-ray Jupiter. Courtesy of NASA/JPL

If this deuterium-fusion really happens it would also explain why some 'hot Jupiter' planets around other stars seem more puffed up than the heat they  get from their star can explain: They are burning  deuterium, and so have more internal heat to inflate themselves.

This is hardly conclusive proof that we should re-label Jupiter a brown dwarf , and declare all missions to Jupiter interstellar expeditions. But it might be an avenue of research that one day leads us to conclude that Jupiter is not quite a star, but still more than just a big planet....Here's the paper.

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Is a grand solar minimum approaching?
Airbus to build space tug