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Wednesday 27 May 2015

Comet 67-P may be a fragment of a destroyed world, and New Horizon's latest images:

Edit: An hour or so after I posted the below the latest images of Pluto from the New Horizons probe were released. Typical (rolls eyes). I'll try to go into them a bit more soon, but for the moment here're the raws:

Above: Pluto - for the first time in history we are seeing details of surface features. Courtesy of NASA.
There are definitely light and dark patches - to me it looks like there might be polar caps, what do you think?

Comet 67-P: Wreckage from a destroyed world?

Ever since the Rosetta spaceprobe arrived in the vicinity of comet 67-P, we've been debating the origin of the comet's famous rubber ducky shape:
If that's an ugly duckling then it's got a lot of work to do to earn a Disney song and a heart warming transformation into a swan. courtesy of ESA
Now, that's a pretty damn deformed duck. I mean, seriously, change the bathwater and stop letting your kid play with a flamethrower in the bath. But, deformed-duck-like or not, one thing is clear: 67-P has two big lumps (called lobes, because scientists need to sound scienc-ey), joined by a short neck. Other comets have ranged from spherical-ish to potato shaped, so what's different here? Two main theories were floated: This was the result of a strange pattern of erosion (the comet gets some fierce erosion it passes by the Sun), or the comet was formed from a gentle collision between two smaller comets. My money had actually been on the first idea, as it's hard to see how comets - objects that move at speeds of over 30 km/ second - could come together 'gently'. But a paper just released by the Rosetta team - full paper here  - has used data from the probes OSIRIS instrument to show that a gentle collision actually fits what we see on the comet quite well.

Above: Comet Wild 2. Still ugly, but a bit more spherical than 67-P. Courtesy of NASA.

The team have a couple of possible explanations: 67-P may have formed during the very earliest years of the solar systems formation, when collision speeds were low and large solid objects were rare. That would make 67-P a hard core survivor, as it would have had to get through the next few tens of  millions years, when the solar system was a cosmic shooting gallery of comets and asteroids. Another possibility is that, during the solar systems later phase of formation,  67-P was formed in the aftermath of the death of a larger, icy, world. The most likely culprit would be a collision between the 67-P parent world and some other fast moving object, resulting in a cloud of debris. The fragments in the debris cloud wouldn't have had much speed relative to each other, and so we have a scenario where a nice gentle collision seems possible.
This would mean that 67-P carried information, not just about how the solar system formed, but about one of the earliest large solid worlds to form in it. Both sections of the comet contain distinct layers, and the team speculate that, if the comet is made from fragments of some bigger world, these layers might be inherited from that parent body. They would hold a record of that worlds history if so - much like the rock layers do here on Earth.

Above: Layers on the surface of 67-P, madse of ice, dust, and a billion horrible smelling organic compounds. Compounds, of incredible scientific value, that might contain the chemical keys to how life started true - but still smelly ones. Courtesy of ESA

Above: Rock strata on Earth. Are tthese a distant relative of the layers on 67-P? They will probably smell better, either way.

Elsewhere in the Universe:
SpaceX have been cleared to launch US military satellites, which should mean a boost in business for them. They have also released a video from inside their Dragon mark 2 space capsule, during a recent test flight that tested its emergency abort engines:

Above: I want one. I won't get one, but I'm going to want one anyway. Courtesy of SpaceX.
Age of the Nanosats?

The private spaceflight industry is heating up in an unexpected way: There are a number of companies who are looking to develop vehicles that can take a human crew on a sub-orbital trip and launch nanosats - miniaturised space satellites like the recently launched lightsail 1 - all the way into orbit. These include some of the best know space start-ups, like Virgin Galactic. Virgin plans to use their White Knight aircraft as a flying launch platform for their Launcher 1 unmanned orbital rocket, as well as their Space Ship 2 manned sub orbital craft.

Above: A quick lowdown on Virgin Galactic's Launcher 1 space craft. Courtesy of TMRO.

In fact the whole field of nanosat launches is looking to be getting more and more busy - is the future of space exploration going to follow the pattern of computers, and be about miniaturisation? Here're a few recent developments:

Above: Swiss Space Systems are a relatively new player, and their sub-orbital minishuttle + orbital rocket combo looks like it has a lot of promise. Courtesy of Swiss Space Systems 

Above: A successful test flight for the Interorbital team. It's not their own ISS exactly, but it's more than I did with my lunchtime (which was eat delicious chicken wings). Courtesy of Interorbital.

Above: A quick run down on Interorbitals unique design for a multi-engine orbital rocket. Courtesy of Interorbital.

Ceres gets more mysterious:
The King of the Dwarf planets has a few strange marks on its face. As more and more detailed images pour down from the Dawn space probe the mysteries just seem to deepen. The mysterious bright spots still refuse to give up their secrets, and the probe is beginning to see evidence of mountains, fault lines, and perhaps even volcanic domes -  all of which suggests that Ceres had - and maybe still has - some kind of active geology. One especially good animation from ZLD over at highlights a bright crater that has an unlikely, steep walled /conical structure:

Elsewhere on the internet:

Sunday 24 May 2015

Q& A with an interstellar dust hunter

The following was a Q and A that was done several years ago - just before I was due to put it up I suffered a personal loss, and the post was forgotten about. Since it was a general Q and A on well established things about what this team does it is 99% still up to date, so without further ado:
Q and A with an interstellar dust hunter:
Manchester - my former stomping ground - is famous for a lot of things - Shameless (Although technically that’s Salford), the Hacienda (although that’s a block of flats now), Manchester United, people attempting to destroy the city centre, etc. But one of the things it should be famous for, is space science.

Above: If you think Astronomers don't know how to party....
No, aliens don't land there (not that people would mind) and it doesn't have a spaceport. But it does have Jodrell Bank, which is still one of the biggest radio ears on the sky Earth has, and the city has the Manchester University Isotope  Cosmochemistry and Geochemistry research group. Have a look at their blog, it's a brilliant window into the kind of space science that gets done right here on Earth.

Image above: The Manchester University team, with the Interstellar Dust Laser Explorer (IDLE) A combinastion of laser and mass spectrometre which can studying the chemical composition of the very tiniest fragments of matter from space. Image courtesy of Manchester University.
 The folks at Isotope Geochemistry and Cosmochemistry use a technique called 'isotope fractionation ', to help them understand the stories behind naturally occuring materials from space. The broad idea is this: Many elements come in a form with a different number of neutrons called its isotopes . This gives the isotope a different mass, so chemical reactions will use different isotopes up at different rates. By measuring the relative abundances of various isotopes - and the abundances of an isotopes decay products - the chemical story of a sample from space can be unravelled. 
Being a meteorite science fan, I thought I’d apply the power of sending an e-mail asking a few questions. Dr Henner Busseman, from the department, has given me more than a few answers!.
So, without further ado:
John: Firstly, thanks for taking the time to talk to me like this. Your group studies the chemical make up of materials from space, dating from 4.5 billion years ago. Could you tell us what kinds of samples you use, and how they are collected?
Dr Busseman: Meteorites – usually from museums and collections (either observed “falls” or “finds”), which are either from Antarctica or hot deserts. Interplanetary Dust particles (IDPs) which are collected in the stratosphere at 20km height by NASA aircraft or [are found] in Antarctic Ice. Solar wind particles collected with the GENESIS mission, and cometary Dust collected by the STARDUST mission.

John: Do samples of space dust tend to differ from meteorite falls?
Dr Busseman: Yes, IDPs tend to be more fragile, fine-grained, organic matter and C-rich, may overlap with most primitive meteorites

John: What do any variations tell us about the origins of these samples?
Dr Busseman: Most primitive samples ( which contain large isotope anomalies in elements like H, C, N, implanted noble gases, fluffy fine-grained texture) may originate from comets, more solid smooth samples with “hydrated” (OH-containing) minerals may originate from asteroids, other samples might be of terrestrial origin (spacecraft paint, exhaust, volcanic ashes)
John: I’ve often read that signs of thermal and aqueous alteration are due to a much greater amount of radiogenic heating in early solar system bodies. How small a body could have had a molten interior back then?
Dr Busseman: We're not sure. Maybe down to a few hundred km or less (perhaps 50?). Model-dependent.

John: How closely does the development of these tiny bodies compare to that of a terrestrial planet? Are some of the same geological proceses (Eg differentiation into core-mantle-crust) involved?

Dr Busseman: They follow the same processes. Terrestrial planets contain many protoplanetary bodies. You can have magma oceans and separation into core and mantle (and crust on top of it) also on asteroids.
John: Presumably any liquid water was confined to the subsurface. Does the presence of aqueous alteration imply large amounts of liquid water, or was it a rare occurrence confined to tiny spaces within rocks?
Dr Busseman: It could be both. You can have aqueous alteration on micrometer sized “contact layers” or due to local heat sources, and macroscopic presence of water, e.g. on the CI chondrite parent body

John: I’ve read that you use isotope fractionation - the relative abundances of isotopes of an element - to trace the chemical processes that have been at work in a sample. Could you give us an example of how measuring isotope fractionation tells us about the processes a sample has been through?
Dr Busseman: Large anomalies, enrichments of Nitrogen-15 relative to Nitrogen-14 or Deuterium relative to Hydrogen can occur only in the low density interstellar medium (ISM) at very low temperatures (e.g. around 10-30degrees Kelvin or so). Finding these anomalies in organic matter in IDPs and meteorites indicates that this matter formed in the cold regions of the protoplanetary disk or the ISM. Many other isotope signatures e.g. in Xe, C, N or O in various minerals are attributed to the production in the various layers in certain stars (e.g. supernovae)

John: How many geological processes can isotope fractionation be applied to learning about?
Dr Busseman: Many. Core formation/differentiation, formation chronology, activity of water, mineral formation/zoning, environmental temperatures during formation, volcanic processing etc etc. => there are many textbooks full of these mechanisms

John: Nickel iron meteorites are believed to be cores of ancient protoplanets/asteroids. How does looking at fragments of a place's core tell us about the history of the rest of that place?
Dr Busseman: The core contains one fraction of elements of the original starting material of an asteroid, the rest of asteroidal mantle/crust can be deduced.

John: Meteorites are often called ‘building blocks of the terrestrial planets’. Does the composition of modern meteorite falls match the overall composition of Earth?
Dr Busseman: No. “THE” building block material of the Earth has not been found yet.

John: Do meteorite falls contain the kinds of volatiles that make up our environment?
Dr Busseman: No. The origin of water and the present atmosphere (e.g. noble gases) is uncertain, and certainly requires many sources(incl. comets). The isotopic signatures of the volatiles in the meteorites and the terr. atmosphere do not match.

John: Both carbon rich meteorites, and samples collected from comets, have shown chemicals that may have been involved in the abiogenesis of life on Earth - for example nucleobases and nucleobase analogues found last year in the Murchison meteorite. What do these tell us about the beginning of terrestrial life?
Dr Busseman: It could simply be possible that some of the ABIOTIC building blocks necessary for the evolution of life (e.g. as simple as CN functional groups or basic organic molecules) might have been delivered by meteorites/comets. If these were available also during the formation of other bodies (in our solar system, but also in other stellar systems) at least some of the basic ingredients necessary for extraterrestrial life might have been present elsewhere. However, suitable conditions are needed (temp., atmosphere, etc...)
John: Thank you for you time Dr Busemann.


Friday 22 May 2015

Lightsail 1 lives, and a student space mission investigates the effects of space travel on salt loving microbes...

Lightsail 1 is alive, in orbit, and preparing for sail unfurling:

Just in case you missed it in the news and my previous post, yesterday an Atlas V rocket delivered a small fleet of miniature cubesat satellites and the US airforce's X37B miniature space shuttle to space.

Above: The launch of the Atlas V carrying the X37B mini shuttle.

THE X37B is testing a new kind of space drive (called a Hall effect thruster),  and so is one of the miniature cubesats: Called 'Lightsail' its planned tp test out a kind of drive called.... (insert drum roll here) a lightsail. This Lightsail is a shakedown cruise to test  some components of the technology before a full trial run in 2016. It's suffered a minor gyro glitch,  but is talking to Earth and on course to unfurl its sail in mid July. Some of the other missions on the launch were:




Unix Space Server Langley


.. and 3 OptiCubes

Students test the survival of bacteria at the edge of space:

Not every space mission is a multibillion dollar effort involving massive rockets and ultra fine instrumentation - there are interesting missions flown all the time that are run by private investigators, or even students. One of these that has caught my eye particularly is a recent edge-of-space mission, using a modified weather balloon, launched by Earth-to-Sky-Calculus, a student led crowd funded organisation.

Above: The halophile bacteria, held in containers of various materials to see how well they're protected from radiation. courtesy of E2S
E2S* are launching salt loving bacteria, known as halophiles, right to edge of our atmosphere to see how they cope. This isn't just petty revenge on the bacterial kingdom by madmen who think they caught colds from their salt shakers: Understanding how well these microbes can survive space conditions will give us clues to how likely life is on Mars, or whether theories like lithopanspermia (basically: Microscopic life hitching rides between planets on meteorites)  might hold any water.

Above: The science payload, as seen by the balloon. High, isn't it?  If you get vertigo you're probably not going to love the next video....Courtesy of E2S
Although the bugs seem pretty resistant to space, one thing is puzzling everyone: During the trip they change colour. So now the E2S team are trying to figure out why with more flights.

These maverik space explorers don't just do serious sciency missions: They also show their respect to their country by put effigies of their president through the harshness of space... and  the subsequent 30km death plunge back to Earth.
Above: Barack Obama falls 30,000 meters from the edge of space. I'm banking on the US republicans to blow my viewing figures sky high thanks to this video. Courtesy of E2S

Elsewhere in the universe:

Above: A map of the thickness of the 'skin' of water molecules on the lunar surface. Blue is more, red less. Thickness seems an inappropriate term, as we literally talking about molecules thick here, but it's still interesting - that's a lot of surface area producing water somehow. Image courtesy of the Chandrayaan 1 mission.
The Moon's poles are known to contain some ice, and (this is still incredible to me, who was bought up with the idea of a bone dry Moon) and a subtle but real water cycle, where water is generated on the surface in an ultra thin skin by some mechanism planetary geologists are still arguing about (see here, here and here. All that's old hat**. What this paper suggests is that the lunar craters might be capable of focusing neutrons reflected off their surfaces. The link between the two things, ice and neutrons, is that the scanning technology used to hunt for ice uses the fact that ice absorbs neutrons - so the levels of ice in some of the permanently shadowed lunar craters might be four times higher than previously thought.

Our space telescopes have opened up a lot of the sky in frequencies that our eyes cannot see, but one range has been largely overlooked: the ultra low frequency radio waves. Earth's ionosphere interferes with these frequencies, so a team from the Netherlands institute of astronomy is suggesting building a network of space borne radio telescopes to finally get a good look at these wavelengths. On a related note, there's new news from Radioastron, a radio telescope already in orbit, here.

Above:  A fleet of these, but in space. Probably smaller as well, or at least foldable.. I don't know how they're going to do it ok, I'm still moving house and I just read the abstract and the conclusions.
On a note about a different kind of space observatory, the paper linked above describes a possible space telescope that would be able to pick out the chemical signatures of extra solar planets...

Lastly we have an idea that weighs in on the entries I ran not long ago about Dyson structures - massive energy farms that could be built to absorb the energy of a whole star, or even a whole galaxy. It seems that we may be looking at the wrong kind of star: Neutron stars might make far better candidates, suggests the paper linked above...

Elsewhere on the internet:

* Yes I think that sounds like a boy band to.
** This is really weird expression IMHO.

Tuesday 19 May 2015

How to see the X37B / Lightsail 1 launch....

I'll have a full post up  tomorrow night, but I need to get this note down today:

Further update: Lightsail has made contact with Earth and is in orbit, but suffered a minor glitch with its gyros.

Update: The launch was a success, no word yet on the condition of the payloads, but it's a good start!
Video of the launch:
Today will, weather permitting, see the launch of an Atlas V rocket, carrying the Planetary Society's experimental Lightsail 1 spacecraft and the US air force's miniature space shuttle, the X37-B. The launch will be from the Cape Canaveral airforce station, at around 14:45 UTC, 7:45 AM PDT, or 10:45 AM EDT.If you're in the area it should be visible for many miles, and loud. Very, very loud. For the rest of us it will be quieter, and broadcast online, live (link at the end of this post)

Above: The secretive X37-B on the landing strip. Courtesy of the US airforce.

Above: The Atlas V rocket, loaded up and ready to go. Courtesy of the Planetary Society.

Above: Fraser Cain talks us through how solar / light sails work.

Lightsail 1 is testing technologies for a new kind of propellant less space engine, the, uh, lightsail. More on that here.

The X37B is on a mission that is largely secret, but which will include:
  • Testing a new form of ion engine (Called a Hall Effect Thruster)for military satellites
  • Testing new potential spacecraft materials in space
The launch will be shown live here.

Sunday 17 May 2015

The race for the next space drive heats up....

The race to the next space drive heats up...

Firstly some breaking news: A Russian Proton rocket has  exploded eight minutes after launch, destroying its cargo which included a Mexican comsat. This will be a big blow for the Russian space agency, who very recently lost a robotic freighter  bound for the international space station, and have had to delay all subsequent flights there as a result.

Above: The rockets launch apparently went well, but not long after this video was shot bad things happened... Courtesy of Eurasianews.

Not too long ago I reported on efforts to build space drives that fly using light (known as solar sails). They work off the principle that photons -  particles of light -  exert a tiny push on the things they hit,  and if a spacecraft with a large reflective sail could catch enough light it could use this push to propel itself.  One such spacecraft has already flown, the Japanese IKAROS spacecraft. Now another is set to fly: A test model of the Planetary Society's Lightsail 1 will launch on May 20th.

The tiny space craft won't actually use its lightsail - it wont fly high enough to escape all of Earth's atmosphere. But it will do some tests and take some pictures. The big test will come in 2016 when the same design  will actually fly under lightsail power. The Planetary Society is not only a private organisation but a public funded one,  so they. 've set up a kick starter to help get themselves off the ground.  More on the kickstarter here

Above: Some science guy, who wants you to help him build a space ship. Apparently he's famous...?

Space recon:
Prox-1 is a potentially revolutionary mission of a different type, launching on the the same 2016 rocket as Lightsail 1: Its aim is to be able to intercept and inspect other space craft- starting with lightsail once its sail is unfurled!  If the idea behind Prox-1 sounds familiar its because, not long ago, the Russian space agency was rumoured to have launched a vehicle that could intercept and 'inspect'  other spacecraft -  some people argued it was the beginning of a new kind of in space weapon. Prox-1 is a US airforce supported project, and is equipped with infra red and optical sensors only. No spacxe guns as far I know. And if it did I wouldn't say (John says as a little red dot centres itself on his forehead..).

Photon Thruster:
The advantage of lightsail's that they wont need to carry fuel - but the disadvantage would be a minute thrust. It's all very well being efficient, but if your SMART car took did 0 to 60 in 3.8 weeks you'd be fairly limited in what you could do with it. You can turbo charge a sail by using a powerful laser instead of sunlight,  but there's a different kind of engine that uses light which goes even further: the Photonic thruster.

Above: The leader of the photonic thruster team gives us some explanation that isn't quite as ham fisted as mine.
The Photonic thruster (which reminds me of the 'photon accelerator drive' in Bucky O'hare)  uses the same principle as the lightsail but uses a n artificial laser light source and adds a second mirror at the source -  this means that the photons keep bouncing between the craft and the laser,  and the craft can keep getting a push from the same recycled photons. Just this week a Japanese team reported their lab based photonic thruster had accelerated a weight along a frictionless track.

Above: The demonstration being used to show how much thrust the photonic thruster can generate
This shows the potential of the idea, but it will be a while before it gets from an idea to an engine as cool as captain Bucky O'Hare's...

Above: Yes, sometimes I just include cool cartoons. It's my blog dammit.

Elsewhere in the universe:
Why that thunderstorm might be a lot more powerful than you think:
Thunderstorms are not exactly known for being quiet,  low profile things.

In recent years they've not just been loud but getting weird as well - a bit like if Thor revealed he'd been rooting for Loki all along -. They've been shown to sprout gigantic jellyfish shaped plasma bolts called sprites from their tops, and it's been known for decades that they can produce other poorly understood phenomena, like ball lightning. Now they have another, even stranger, feather in their cap: They make antimatter - that's they ultra explosive stuff from that movie with Tom Hanks in - something that we can only do in particle accelerators. The lightning bolts in a storm produce brief pulses of antimatter through some unknown mechanism - and and given the power of antimatter a lot of people would like to make that mechanism known. Link here.

Wild 2 comet gets weirder:

Above: Wild 2, looming out of the darkness like... like.. um. One of the things about space travel is that, often, what you see doesn't compare to anything else. Courtesy of NASA.
Comet Wild 2 has already rewritten everything we know about comets once, when samples returned from it by the stardust space probe revealed it contained material formed at high temperatures - a bit odd for a giant snowball. Now the Wild 2 samples have changed the game again, by revealing that the finest grained dust in them is either from all across the inner solar system, or is preserved material directly from the protoplanetary disc that formed the planets. Link here.

How did Earth survive the faint, dim Sun?
Above: Earth as an iceball. Courtesy of the BBC. The image that is, not the ice age.
One of the puzzling things about the solar system's deep past is that the Sun would have been a good deal fainter. So faint, in fact, that both Earth an Mars should have been ice locked. Yet we have tons of evidence that both planets had liquid water at that time, and that life on Earth was able to get started.Now a study from the Sternberg astronomy research centre has suggested an answer: If the Dark energy field, thought to permeate the universe, has a certain range of uniformity  then it could have caused the planets to spiral slowly outwards over time. This would mean that Earth started its life closer to the Sun, and moved further away, keeping the temperature more or less constant. Link here.

Elsewhere on the internet:

Dragon space capsules might become the workhorse of deep space exploration:

Does dark energy make us exist?

Neutrinos come in three flavours

Miniaturisation: The final frontier

Another dark matter search comes up empty

Wednesday 13 May 2015

New Horizons begins to see Pluto, and ISS videos....

This week is turning out to be a busy one, not that my fellow space nerds and I are complaining!

Pluto's moons come into view:
As the  New Horizons space probe nears Pluto it's beginning to see features on the surface of the icy dwarf planet, as well as the cluster of  moons that swarm in orbit around it. In the animation  below (from the beginning of the week) the probe was beginning to see the moons Nix and Hydra..... 

Above: A n animation made from images taken by the New Horizons probe, showing the motion of Pluto's moons against the background stars. Courtesy of Fred Bruenjes
 .... a few days later the Moons Syx and Keberos are beginning to be visible as well.

Above: More moons! The space near Pluto is a veritable maze of icy chunks. That's amazing science, but possibly not so good if you're a space probe about to fly through that space at over fifteen kilometres a second
One thing about Pluto and the moons, which has already caught commentators interest, is that they appear to change in brightness. On Pluto itself the New Horizons team are confident this means they are already seeing surface features....

Above: Pluto and Charon (a view taken earlier than the previous ones) showing some surface features on Pluto and the  way that they orbit each other, as Charon's mass is so big compared to Pluto's. It's like when a small granny picks up a big baby and has to hand it to someone else almost immediately because it's pulling her over. Well sort if.
OK, not really then, but a bit. Courtesy of NASA
.... and it might also be an early indication of surface features on the moons, or that the moons have an irregular shape.
“Detecting these tiny moons from a distance of more than 55 million miles is amazing, and a credit to the team that built our LORRI long-range camera and John Spencer’s team of moon and ring hunters,” said New Horizons Principal Investigator Alan Stern.

Elsewhere in the universe:

Yet another cool animation of Ceres:

This time it's the mysterious bright spots....
Above: The brightspots on ceres, courtesy of ZLD of

If you look closely at the above section of Cere's surface you might see that there seems to be some sort of linear feature running under the crater with the bright spots. One theory being advanced is that the impact hit a geological fault line, and created a weakness in the crust through which fluids could seep.

Videos from the ISS:

Life as an ISS crew member seems to be full of adventure and drama (it's a job in space, so that it'd be a lot more surprising if it was on par with a standard office job), from docking private space ships, to searching for dark matter, to out of control space freighters. But the crew also do more mundane, day to day tasks, such as exercising to keep their muscles from wasting away and running the stations many science experiments. Astronaut Samantha Cristoforreti has found time to put together a collection of videos sharing it with us all

 Above: Here's one video, and if you follow the link above you'll see a whole bunch more. Courtesy of ESA.

Samantha may well be making more of these videos than she'd originally planned, as her ride home has been postponed following a malfunction on board a Russian Progress freighter that caused it to burn up in Earth's atmosphere without delivering its cargo.

Elsewhere on the internet:

Stephen Hawking to appear at Glastonbury festival (yes you read that right)

Inflatable aeroplane to explore Venus?

Are mass extinctions linked to Earth's travel through the galaxy?

Does Europa's salty ocean spill onto the surface?

Tuesday 12 May 2015

A quick note on the new news from Ceres

For a while now the Dawn space probe has been orbiting the Dwarf planet Ceres, the biggest little world in the asteroid belt, and during the last couple of weeks it has been spiralling downwards, into its science and mapping orbit. Long before Dawn arrived we new, from Hubble space telescope images, that there was a very unusual, bright, feature on the surface of this little mini-planet. But when Dawn arrived the mystery only deepened: the bright spot turned out to be far smaller, and far brighter than anyone had expected. Now the latest, amazing, images are down from Dawn, and do we have an answer?

Above: An animation composed of images taken by dawn, showing Cere's spinning undernaeth the probe. notice how many tensy little bright spots now join the big one. Courtesy of JPL/NASA
No. Don't be silly.
Nature isn't giving up here secrets that easily. We can now see the structure of the bright spots, but we're no closer to understanding what weird kind of alien geology has produced them. In fact the mystery deepens: We can now see the bright spot is actually a cluster of scattered bright pots - and there are more, smaller, bright patches scattered across the surface!

Attached Image
Above: The biggest bright spots, shown just as the Sun is rising on them and at around midday. We're beginning to see structure here, but still have no idea what it means. Courtesy of JPL/NASA/

The bright spots aren't the whole of the strange story though. Ceres has a number of enigmatic mountain like features. The one in the animation below definitely looks like it might be volcanic in origin, which would make it a marker of cryovoclanic (volcanoes that erupt melted ice instead of rock) activity - which in turn could tell us how long ago Ceres definitely had liquid water beneath its surface, and what the chances are that any remains today

Above: A close up on a possible extinct/dormant cryovolcano.
The most intriguing suggestion I've heard so far is that, although Ceres is predicted to be ice rich, these bright spots are actually deposits of salt. That would make sense if Ceres had a salty, or other chemical, rich underground ocean . If it did then one sequence of events that might explain the bright patches could be as follows:

- Melting ice rose through the crust (i.e. 'cryovolcanism') via fractures caused by impacts or tectonic forces.

- Salty deposits were left behind along the fracturess as intrusive deposits,  and salt water  may have erupted onto the surface.

- Subsequent impacts and other erosion have cause exposed salts to fade over time.

- In a few cases an placed impact or landslide could expose some of the preserved deposits.

I've read people of a geological background proposing very similar explanations in a few places. Dr Tom McCord, a co-investigator on the Dawn mission, has gone on record at a Seattle astronomy event as saying he thinks these bright spots could be salt deposits. There's more on what he thinks Dawn is seeing here.

Monday 11 May 2015

Is time distorted across the universe?

The history of dark matter, and our search to pin down what it actually is, is fraught with difficulty: We're confronted with a universe where an invisible force, which we cannot directly detect except by the effects of its gravity, is altering the rate at which the galaxies themselves spin.
Then, to make matters much worse, along comes dark energy: An even more mysterious force, which we also cannot directly detect, that is effecting the rate at which the universe itself expands.

Above: The odd way galaxies spin, and why dark matter is proposed to explain it, all presented at a high school maths level - thank you TheCosmicWeb

Scientists really don't like having to explain the things they see in the universe by resorting to invisible matter, undetectable energy, or anything else unseeable. It's just too easy, as you can use it to explain almost anything. And the failure - to date - of our most sensitive instruments, including the alpha magnetic spectrometer mounted on the hull of the ISS, to find any definitive evidence of dark matter (beyond its gravitational effects which is what it was was proposed to explain)  has led to some interesting non-dark matter explanations for the strange way we see galaxies spin, and the way the expansion of the universe seems to be accelerating.

Above: The Alpha Magnetic Spectrometer, a tool for hunting dark matter, mounted onto the side of the ISS. Courtesy of NASA
Mostly these explanations fall under the umbrella term of MOND (MOdified Newtonian Dynamics) a collection of theories that suggest that gravity doesn't work quite the way we think it does long distances. By and large they haven't managed to usurp dark matter and dark energy as the leading explanations for the strange observations, but they do represent some interesting thinking.

Above Neil deGrasse Tyson explains the MOND vs dark matter debate in a radio interview. Courtesy of Startalk radio

Today, however, I've run across a deceptively simple alternative to both dark matter and MOND. The idea being tentatively proposed, by P. Magain and C. Hauret from the Institut d’Astrophysique et de G ́eophysique in Belgium, is that maybe it isn't matter or gravity that isn't behaving like we expect.

Maybe it's time.

Einstien's theories of general and special relativity tell us that it's possible for the flow of time toi be changed locally by either an object moving very fast, or an object having a very powerful gravitational field. But on the largest scales cosmologists usually assume that the flow of time is pretty much even. Magain and Heurets suggestion - which fits some observations almost perfectly but has yet to be tested against others - is that the flow of time on very large, universal, scales is tied to the entropy of the universe, and so might vary. If time can vary as we look out across the universe, then that might explain some of the strangely moving things we see - they are moving according to the physical laws we know, no dark matter or energy needed, but we are seeing them out of sync with each other..

I'm only going to put up this quick note on the subject at the moment, but the simplicity and audacity of the idea makes me wonder if it doesn't have alot of potential, so watch this space. The paper is here

Sunday 10 May 2015

Are we asteroid dust?

Are we asteroid dust?
Where did life come from? From all over the solar system, according to a study by Ben K. D. Pearce and Ralph E. Pudritz from McMaster university. They suggest that the building blocks of life may each have largely originated on a different protoplanet in the early solar system, as the result of different conditions on those worlds.

Why does that matter? Well it won't cause traffic jams of people rushing to the bunkers in case the aliens are coming. But it might be giving us a piece of the puzzle of how life began: One promising theory of how life formed is that prebiotic molecules, each having one or two lifelike properties, were bought together by chance and stayed together because their ability to survive was greater that way (religions across the world have much more fun ones, involving life being made of clay, people being made of other peoples ribs, the sky being made from a huge skull, etc. etc.).
For example; lipid molecules can form enclosed cell walls when mixed with water, and these enclosed cell walls will grow and replicate (two things that life does). But they have no means of evolution... unless they joined forces with RNA molecules at some point (which can evolve). Together the two systems were able to spread further, and were more robust, and were able to evolve.

So where did those prebiotic molecules-with-some-lifelike-properties come from? The same place, it seems, that the rocks and water of this world came from: Space.

Above: A simulation, showing planets growing from the rocks and ices in the protoplanetary disk. Courtesy of Michegan University.
Yes, in case you haven't read my ramblings here before: Earth (as far as we know) was formed by the collisions and mergings of countless billions of protoplanets, asteroids and planetismals, in the swirling mass of the Sun's protoplanetary disk. Because there were more radioactive materials around back then even very small worlds had enough energy for things like volcanic activity and (subsurface) liquid water.
Above: A full talk on how tiny worlds in the ancient solar system could have things (like volcanoes and magnetic fields) which only full sized planets can have today. Courtesy of Havard-Smithsonian
So, before Earth ever formed, the primitive organic matter already present in the protoplanetary disk was being changed by these processes into more complex stuff. When these worlds splatted into each other, or got merged into planetary embryos, chunks of them containing the processed organic matter - things like amino acids (which build proteins) and nucleobases (which build RNA and DNA) - were blasted into space and eventually fell onto the young Earth,

Which is where the new study comes in: By looking at various pre-biological organic molecules, from a range of meteorite families, the team from found evidence that some of the parent worlds shared the same chemical reactions, and some of them had different reactions going on. This meant that some of these early worlds were making mainly DNA building blocks, and some were making more protein building blocks (or sugars, or something else).

It all adds to the picture that the ancient solar system had many, many worlds, each with their different character. And the origin of life is tied up in what happened on these worlds, long before the Sun ever rose on early Earth.

Elsewhere in the Universe:

For a long time it's been an unresolved question: where did Earth's water come from? Recently evidence from the Rosetta space probe, which is exploring comet 67-P, suggested that Comets were a less likeyl source of water. As the Earth itself formed from asteroids an comets this made water bearing asteroids a more likely source, and now observations of an asteroid impacting a white dwarf (a dead and fading star) have provided evidence that water bearing asteroids may be common in other solar systems too.

Most planetary geologists are pretty convinced that there's a sea beneath the ice of the south pole of Enceladus. But that's a different kettle of fish from that ocean having the chemical ingredients neede for life. We know there are signs of organic molecules in the material being vented from the ocean into space, but is there a chemical power source for living organisms? New evidence suggests that there is: A process called serpentization may be able to set up the energy gradients needed.

Scuttlebutt on the interweb is that there's a renewed push for the Europa Clipper mission to get a lander. A lander portion of the mission would enhance the chances discovering life there, and, as U.S. Rep John Culberson, who oversees NASA's budget, said "Why go there and not answer the most important question?"

Although the MESSENGER space probe to Mercury has been slammed into the rock of that planet at 8000 km/hour (space exploration allows you to throw out the trash in a way that would demolish the town) the data it has sent back will be picked over for many years to come. One result that has cropped up recently is that the magnetic field of Mercury may predate even Earths.

Curiosity sends back stunning picture of the Martian sunset:

Above: On Earth the sky is blue and the sunset orange. On Marsv the sky is orange and the sunset is blue. Why? Because if the skys and sunsets were the same the hoax theorists would never, ever, shut up. Courtesy of NASA

Elsewhere on the internet: