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Tuesday, 27 January 2015

A good day for exploring asteroids and comets...

Belated happy Burns Night everyone - if you don't know what Burns night is... don't worry too much, but you've missed an excuse to have a party, and read some mad poetry.

Elsewhere in the Universe: Small worlds seem to be in the news a lot today. The newest images from the dwarf planet Ceres have come back form the Dawn mission:

Above: Ceres - images like this are kinda like the teasers before a movie, admittedly a movie aimed at astronomers and geologists, and where the stars are gigantic balls of rock and ice doing weird things, billions of miles away...
Above: A GIF of eres rotating back and forth. It makes some of the details more obvious. And it looks kinda funny. Sincere thanks to Toma B of

See the latest video of the dwarf planet here.

A few things jump out from this (now twice as clear as Hubble) set of images: The bright spot is still mysterious, but now we can see there are other, smaller bright spots further around the dwarf planet. The big bright spot is definitely surrounded by something darker - it could be shadows from surrounding mountains, although I'm not sure that the sun is at the right angle for that. There are definitely depressions that look like craters, most visible near the edge of the night side -  if the bright spot is a crater which has punched into a layer of subsurface ice (still my theory) then I wonder why the other craters haven't? There are what look, to me, to be mountains winding in unbroken lines across hundreds of kilometres of the surface. That must be pretty spectacular from the surface! Maybe it's just the low resolution (20 km / pixel) but somehow the surface looks rippled - what do you think?

Above: This is one of the Goldstone antennas, but it's mainly here because its pretty.
Earth travels through space at 30 km a second, and sometimes it passes other places that are interesting - to explore them we have things like the Goldstone facility - it fires a beam of radio waves into space and builds an image out of the echoes.  The Goldstone radar video of asteroid 2004 BL86 -  a mountain sized that Earth passed by last night -  came up with a surprise: It has its own teensy little moon!

Above: The asteroid, and it's weensy moon. Two things are surprising here; that such a tiny world has become more-or-less-round, and that so may asteroids are being found to have moons.

Radio observatories like Goldstone have made a lot of discoveries that would have other wise needed a space mission, like the ice in the eternally dark craters on Mercury:
Above: Images of the ice on Mercury - a big discovery considering how scorchingly close to the Sun Mercury is - taken from Earth by the Goldstone radar. Courtesy of NASA.

Lastly another small world,, the 100 km wide 'mega comet' Chiron, has thrown up a surprise: It has a system of rings!  This would make it the only known comet to have rings - it's just a pity this world is even further away that Saturn, so it'll be a long time before we get a decent image of them....

Above: An artists impression of Chiron, without rings - well there's a project for Many worlds art...
Elsewhere on the internet:

Go to Congress and stand up for exploration!

Another ancient habitable environment on Mars.

Latest news on the fountains of Enceladus.

Meteorite mineral named after beer is a time capsule.

Experimental 'Light Sail' space drive to fly soon.

New network of Earth observing Satellites

New satellite network to expand the internet.

Big International Space Station robot unloads experiments from recent cargo run

Saturday, 24 January 2015

Rossetta, Philae, and the comet that wants to be a world...

My apologies for the way the font changes part way through - I'm working to fix this but blogger isn't playing tonight - I'll keep trying and I hope it doesn't spoil your read! JF

Rosetta, Philae, and the comet that's trying to be a world...

Late last week a whole bunch of reports and papers from the Rosetta mission - a space probe on a mission to explore a comet - were released This is a link to all the reports, and here's the quick version. I've been reading through them, because, well, I'm space nerd.

I might even have a set of Star Trek PJ's. Maybe

But never mind that - it seems as though this comet doesn't know it's meant to be just a big chunk of ice...
Above: Rosetta has a camera called 'Navcam'- it's the robotic equivalent to your night vision; black and white, good enough to let you find your way about in the dark, and the comet is very dark. This is what Navcam sees. Courtesy of ESA 

Firstly, the comets resemblance to a gigantic rubber duck still defies explanation - either this is two comets that have somehow stuck together, or one comet shaped by some weirdly selective force of erosion.

There's a space alien out there, watching us all scratch our heads, and it's sniggering.
What can be said for sure is that the head, neck and body all give off different kinds of gas and dust, at different rates, with the neck giving out the mostly water vapour, and the body giving out CO2 and CO. That sort of suggests this is two comets stuck together, but that begs the question 'how the hell did that happen?' A collision at the sped things travel in space should have pulverised them both..

Above: This is actually far slower than things would happen in a real space collision - in reality you'd never see the debris, it's going too fast for you eye to pick up. Everything around you would just start sprouting massive holes and exploding ... hard to get anything to stick together!

On the comets surface things don't look like people were expecting either: Ever since the first images came back people have been looking at these things:
Above: ESA travelled billions of miles into deep space, and found a scene out of Lawrence of Arabia.
...and going  'those can't be dunes, dunes need an atmosphere and wind to form'. It turns out that these are dunes- the gas surrounding the comet is thin, but the winds in it blow at up to 300 meters a second - fast enough to blow surface material into dunes. 

The surface is covered in several distinct varieties of terrain, including deep, circular-ish pits, like this:
Above: The dark and twisted surface of comet 67P. Definite proof that even the laws of nature have gothic moments.... Courtesy of ESA
At the moment they're choked with dust and debris, but when the comet is warmer they are probably where a lot of gas a dust shoots out - some of them are already starting to 'geyser':

Above: This over exposed image is bright enough to show the jets growing from the pit. Courtesy of ESA.
One of the pits has a formation that looks as though the comet has erupted some kind of fluid material:

Above: Theory says this strangely flat material was probably the result of something that flowed like a fluid.. in a place where fluids should be impossible.... Courtesy of ESA
This fluid probably isn't water - although signs of liquid water have been seen in comet material. It might be something like a cold version of a pyroclastic flow - a terrifying fluid-like flow of  ash, rock and scalding gas that comes out of volcanoes:

Above: Not as bad as it looks, much, much worse.

Another oddity is the presence of clusters of bright bluish objects at ten or so locations. They seem to be ice rich, but the rest of the surface has had the ice baked out of it by the Sun, so where did they come from, and why are they gathered together in particular spots?

Above: The clusters of icy objects. Um... snowmen, perhaps? Courtesy of ESA.
67P also has a structure like no iceberg: The comet overall has the density of cotton wool, and must have a structure something like frozen foam, getting less dense towards the middle. The surface actually has hardly any ice at all, and is made of  a very red-black, brittle material, that acts as an amazing thermal insulator - even though the surface temperatures are already getting up to - 40 deg C (That's very surprisingly warm considering how far it still is from the sun) the heat hardly penetrates any depth into the comet.

Above: Mmmm... chocolate truffle.. no.. wait, huge space thing! I keep making ta similar mistake with the Sun, and calling the electricity company when my light switch won't turn it off...

Then there are these odd 'goosebumps' . Regular lumps in the comets flesh. There're all about three meters across, composition unknown, and show up anywhere the comets subsurface has been recently exposed. Current best guess is that they could be the basic building blocks of the comet itself - whatever they are, the similarities make it likely they all formed the same way....

Above: The 'Goosebumps' are everywhere on this comet - it is chilly there, but 10 foot wide bumps seems excessive. Courtesy of ESA.

The last thing I'm going to mention - although not the last odd thing or mystery in the reports by any means - are the jets of gas. Now, at the moment these seem to be blasting out of the neck region. As far as anyone knows the only possible way these jets are powered is from sunlight heating the comets surface. But measurements of which jets are strongest seem to show that the strongest jets are coming rom regions that re in the shadows - and the shadows of a comet are deep, cold, and sunless places. This really suggests that either we've got the way the comets internal structure transports heat very wrong, or we've somehow got how the jets themselves are powered wrong - we'll need more time to figure that out.
OK, not the last thing I'll mention: Rosetta has captured dust grains being ejected from the comet, and studied them with its mass spectrometer - a device that gives chemical composition. It's found a fantastically complex mix of organic chemicals, and the team are still trying to unravel the readings. But they've found alcohols, carboxylic acid (which goes into making proteins) and aromatic and aliphatic molecules (aromatic = organic molecule with rings of carbon atoms aliphatic  = organic molecule with no rings) These could include amino acids, which are an important chemical step towards life, and have been seen in comets before.
As for Philae, the MIA lander that is somewhere on the comets surface? The robot is still missing, but its results are rumoured to be up for release soon.
This is going to be an interesting mission....
Elsewhere on the internet:


Tuesday, 20 January 2015

Dawn of a new age of rockets?

I couldn't not share these quick videos with you. First: SpaceX made their first attempt to land a re-usable rocket booster on an unmanned floating landing pad in the middle of the pacific ocean:
 Above: This what happens when you let R2D2 drive...
What exactly is happening here?

OK, obviously, the rocket smacks into the landing pad and explodes.
The latest SpaceX cargo launch to the International Space Station had an experimental first stage that could fly back from the edge of space, find its landing pad in the ocean, and land on it. If this technology can be made to work then it would help to lower the cost of access to space for the future - and this is actually not-too-bad for a very first test of an experimental technology: The rocket found its way back to the pad from the edge of space, approached it at a sensible speed, and then crashed. The fact that the first worked thirds of the mission worked first time is promising, and the reason it all went wrong - the guiding fins on the rocket base ran out of hydraulic fluid too soon - is fixable.
SpaceX has been in the news a lot this week: They're starting a satellite building operation in Seattle, with which they plan to expand the internet.
Second: The Dawn mission has come close enough to the dwarf planet Ceres to start taking pictures of it - here's the video of the planetary embryo:

Ceres is a relic, a planet that had its growth stopped at a very early stage, which makes it a fascinating target. But what's really caught everyone's attention is the bright white dot - it's caused a fair bit of speculation, and it's showed up on Hubble images to:

Above: If you take the pixels away and that's the death star then a tiny part of my brain will go 'Coooooool!'. The rest will start gibbering.

Computer simulations of Ceres early history suggest it has a massive amount of water ice in its interior, and perhaps a deeply buried ocean near its core - so my guess is that the bright spot is a crater that has punched through the dusty surface and into the bright layer of ice beneath. But there are other possibilities: The Herschel space telescope discovered water vapour over Ceres not too long ago - so this could even be geyser of some kind. We'll find out more as the Dawn spacecraft gets closer to this billions-of-years-ancient world....

Elsewhere on the internet:

Nanobots become real

ESA builds up to spaceplane test

ESA builds closer ties with China

Saturday, 17 January 2015

Venus: A hell world, wearing silk pyjamas...

Venus: The smooth blue of the dayside (seen in UV light) contrasts with the infra red view of the night side, showing infernal heat seeping out of the clouds
Despite having cooked up in Venus' atmopshere in December 2014, the Venus express spacecraft keeps giving us new discoveries (link here). JAXA has bought their Akatsuki spacecraft into orbit around Venus, and are preparing for their own science campaign. Terrifying as it is to us humans, Venus is also a fascinating place, so it seems appropriate to look back the discoveries Venus Express made, the incredibly strange world it revealed, and what the future of Venus exploration holds.

Mysteries beneath the clouds:
Once Venus was just a bright, beautiful, point of light to us. Then the space age revealed it as a world like some cosmic lab experiment run wild. The surface is drowned beneath an ocean of supercritical carbon dioxide - the pressure and temperature (450 degrees Celsius, 90 atmospheres) beneath the clouds that the CO2 enters a weird state called a 'supercritical fluid', that is neither liquid nor gas.
On the scalding surface radar images show that there are more volcanoes than on any other planet, and signs of ancient lava flows  - but spotting an active volcano  from a dormant one at the bottom of a ocean of hot, high pressure, CO2 isn't easy. What is clear is that, at some ancient point ,some unknown catastrophe covered the whole surface of Venus in lava, obliterating almost all traces of the world that was there before. 

Above: Take the lava in this video and multiply it by 'the end of the world squared' and you'll have some idea of what it was like on Venus at that time. Courtesy of volcanopixs

It gets odder: Radar scans show a bright coating on the mountain tops, but strange, dark patches covering the highest peaks - the best explanation anyone has is that the mountains get snow.. made of heavy metals:

Above: Yes, this is a very silly pun*. But doing a 20,000 mph death dive into a hell planet ... that is very, very, metal. So this for metalheads everywhere - and next time you're in the mosh pit, think of Venus Express, going down in flames..

But the 'snows' have holes in them that are incredibly dark to radar, much darker than anything else on the surface. That makes no sense, and no-one as a solid explanation (this is not something scientists like to admit, but they really don't).
Above: The radar-bright 'snow', sitting on a plateau on the surface of Venus. Image courtesy of NASA.
If anything makes Venus special, it's that pressure cooker atmosphere/ocean. Topped off with chemically complex sulphuric acid clouds, it's unlike anything else in the solar system. It's also a law unto itself: The atmosphere spins faster than the planet it hides, is full of the odd: Unexplained UV absorbing chemicals in the clouds, bacteria sized particles in its clouds, and an unexplained glow called 'ashen light', to name just a few.
Not only that but, even though the clouds rain battery acid that boils before it hits the distant ground, at 70 km altitude there is a layer that is more Earth like than anything else in the solar system. In fact, after finding organisms that thrive in highly acid conditions, there are scientists who put forward the idea that some of the unexplained chemical imbalances, and hard to produce chemicals, in the Venusian clouds were there due to an exotic form of life...
That was Venus before Venus Express arrived: A high temperature, high pressure physical and chemical enigma. Afterwards.... its still a  high temperature, high pressure physical and chemical enigma. But now we know of even odder things....

What Venus Express saw:

The Venusian day has got six minutes longer since the last probe visited:
On Earth a really massive earthquake can change the length of the day by fractions of a second. Since the last probe visited the day on Venus has got longer by over six minutes. So something big is happening there - we just don't know what.....

The incredibly powerful winds are getting stronger, somehow:
The winds of Venus blow at up to 300km an hour. Since the last probe visited they have gotten faster by 100km per hour. There's no clear reason for this, but, again, something big is happening at Venus.
There's something about the poles of worlds that lend themselves to strangeness. Saturn has its giant hexagon storm, the Moon has the mountains of eternal light and valleys of eternal darkness. Venus has... this...

Above: The twisting vortex(es) at the pole of Venus, shot in infra red , so the heat from the scalding surface can highlight the structure. Courtesy of ESA

When asked 'What the hell is that?' most scientists involved with Venus Express describe it as 'a giant hurricane, with two eyes, sitting right over the planets pole'. Although, over time the central vortexes began to twist into all kinds of shapes, beside the double eye one, so I think  'we're not sure guv' would've been closer to the truth...
At around the time Venus express arrived, some thing injected a massive amount of sulphur dioxide into the Venusian atmosphere. Over time the levels steadily decayed, in a pattern that exactly matches the way a volcanic eruption on Earth throes sulphur dioxide gas into the atmosphere. On top of that there are volcanoes like Idunn Mons which show signs of having fresh lava flows around them:

Above: An infra red map of the volcanic mountain Idunn Mons on Venus. Just being on the surface of Venus is a bad place to stand, so this volcano is the definition of an extremely bad place to stand . Courtesy of ESA

The probe also saw searingly hot flashes from volcanic vents even hotter than the rest of the scorching surface, adding the words 'explosive' and 'lava' to a description of the surface that already reads like hells more unstable cousin.

Venus has an ozone layer, albeit a very thin one. A lot of astrobiologists had a thought that the presence of CO2, oxygen, and ozone in an atmosphere together could only be a result of life... the take home message here is that it's a good idea to check your theories against the facts.

Venus had water, oceans, continents:
Above: Venus, with water -  looks inviting? Fancy a swim? Too bad, it all boiled billions of years ago..

One of missions finds highlights how lucky Earth is to have a natural magnetic force-field keeping the solar wind (a wind of electrically charged particles from the sun) out: It's already known that this wind helped devastate Mars by gradually blasting most of its air into space. Now we know that it does something similar to Venus, but at Venus the victim is the planets water, which is broken down by sunlight, and then whisked off into space by the solar wind... if you work the numbers of how much and how fast backwards, it turns out Venus must have had a lot of water at some point. Like Mars, Venus was definitely a water world.
A closer analysis of the surface also shows that the high plateaus on Venus look differently eroded than the basins, something that would make sense if the basins were filled with water, and the plateaus were continents, in the distant past...

The air really does glow:
The atmosphere contains a chemical called nitric oxide - it gets used a lot in chemical industry here - that makes the atmosphere glow. But this doesn't explain the 'ashen light' mentioned above, as the glow is infra red. Incidentally nitric oxide is such a useful molecule it was named 'molecule of the year in 1992.'

....It's also electrically charged:
All those charged particles slamming into the Venusian atmosphere generate electric currents in the upper layers.

The  acid clouds produce lighting!
Above: Artists impression of Lightning on Venus. Cool. Unless you're riding that balloon.

This was a big question mark before Venus express. Lightning had never been observed in clouds made of sulphuric acid before, and lightning can have surprising effects on the atmospheres chemistry by producing compounds that otherwise would not exist.

Venus is till scalding, still weird, and still fascinating - so what next?

The Japanese Akatsuki spacecraft recently arrived there - it was supposed to enter orbit around Venus in 2010, but a malfunction left it orbiting the Sun. Luckily orbital mechanics offered a chance for it to complete its mission, and use its remaining fuel to enter orbit.

Beyond that.... the are big plans, although nothing concrete: Manned flyby's, balloon probes, surface rovers, even floating cities....

Time will tell.

Tuesday, 13 January 2015

Titan: 10 years after contact....

It's been a grim week in Europe - I'll say no more because, if you follow the news at all, you know exactly what I'm talking about. But that makes it all the more important to celebrate the awesomeness of things that are good, and the achievements that are great. And this Wednesday we have the anniversary of something very awesome to celebrate:

Landing on Titan:

Above: Titan, as seen with Cassini's haze piercing infra red camera.

The first ever landing of a space vehicle from Earth - The European Huygens probe -  on Saturn's largest moon: The  mysterious, organic haze shrouded, Titan.

Above: The descent of the Huygens lander to the surface of Titan. At first the view is a fish-eye view from the bottom of the lander, with all sorts of technical stuff flashing up, and the radio noise of Huygens  talking to its Cassini mothership. Then the view  switches as the probe lands, in a 'sand' of ice particles, soaked with liquid methane, and coated in hydrocarbon gunk.

The Huygens probe is still the furthest craft to ever land on another world, and it was sent as part of the Cassini mission - a collaboration between NASA and the European Space Agency. The bus sized Cassini probe is still orbiting Saturn, exploring all its complex moons from above. But Huygens showed us a ground level view of a world that turned out to be a frozen, twisted, reflection of Earth. A world with seas of natural gas that have no waves, 'magic islands' that appear and disappear, and a chemistry so complex some scientists believe it may be similar to that which gave rise to life on Earth.

Beagle 2 may be found:
Above: The beagle 2 space probe. Not the real one, obviously, as it's probably in bits at the bottom of a hole on Mars.

It's also fun to celebrate bold and brave failures: The Beagle 2 space probe to mars was one of these. the mission vanished in 2003, but the buzz on the internet is that its landing (or probably crash landing) site may have been spotted by the Mars Reconnaissance Orbiter mission. We should hear for sure on Friday!


The new Avengers trailer is out! 'Nuff said.

Above: Stark put on weight.....

Saturday, 10 January 2015

Dust, the ultimate cosmic mystery (maybe)...

Above: The Zodiac light, a glow in the sky caused by sunlight reflecting from trillions of bits of space dust.
This week I was wondering what to write about. Venus exploration maybe, or SpaceX attempting to make a re-useable rocket (they had a bad day, but that won't stop them) or perhaps rumours of killer space satellites
Then inspiration came from my book shelves: 
Above: Yes, those are Deadpool action figures, Minion soft toys, complete collections of Hunger Games, Game of Thrones, and whole shelf of comic books. How can I be this nerdy? My fiancee heps me a lot.
I can write about dust!

Ahem.. I promise this is going to be interesting:
Dust is an important thing in space. Last weeks 225th American Astronomy Society meeting had a huge number of papers on it (follow the link, close the pop up, and search for 'dust' and you'll find them). NASA has special planes just to catch it falling from space. Space missions worth tens of millions been launched, just to find a few grams of it.

Above: The Hayabusa 2 space mission launches to collect asteroid dust.
Why? Because space dust is old, strange, stuff: It was the first solid matter in the universe. It was the building material for all the planets, dwarf planets, moons and asteroids. Thinly spread dust fills space: Some is ‘just’ from asteroids and comets, and some actually grew in the outer layers of ancient stars, or was forged in a supernova. Even garden variety space dust contains rock, water, gases like oxygen, and precursor molecules to life - basically all the stuff that goes into making a world like Earth.

In fact planets are small fry for space dust. Paradoxically, space dust thinks big. It forms massive structures, trillions of kilometres aross, as it gets blown about by stellar winds and pulled by gravity,  like nebula.....

Above: A vast nebula of ionised gas,  and stellar dust. Courtesy of NASA
... bok globules... 
Image above: Bok globules,  cocoons of dust where stars grow.  Courtesy of NASA

...and the pillars of creation and destruction,  which were captured in a stunning new image by the Hubble released this week
Above: Ohh,  pretty.  Courtesy of NASA
These huge structures give birth to stars, planets, and solar systems – and they’re everywhere! Look up at the milky way. See those dark patches in it? Clouds of space dust waiting to form planets.

This tendancy to bigness has led to a suggestion that we could use this ability to build massive space telescopes from dust.

Astronomers started digging deeper, and experimenting. Which is when things got weird*: A paper published at the 225th AAS meeting this week shows that the dust some parts of the universe is definitely being destroyed faster than it should be being created, or moved in.
So where is it coming from? We know of some sources - dust can grow in the outer layers of stars for example - but they can’t produce all the dust we see.... we just don't know. 

Space dust does even stranger stuff: Dust rings,  like those around the giant planets,  can turn cosmic rays (which come zipping through space a lot) into antimatter. In case you’ve never seen any sci-fi: Antimatter is the ultimate space ship fuel – and the ultimate weapon: One pea sized piece could produce more power than a Hiroshima bomb. A scheme has been suggested where robots could harvest antimatter from the rings of Saturn. Dr Evil never dared dream such a supervillain plan, yet it's a real (eventual) possibility.


From there the story of dust gets really odd: In 2007  researchers showed that a mix of space dust and plasma - which space is also full of - could give rise to  replicating, evolving, DNA like,  dust spirals - a bizzare kind of quasi-life..... 

To throw some light on space dust astrophysicists wanted samples of the dust in interstellar space – the type with the biggest question marks over its origin – that forms young solar systems. But, even travelling at 45 kilometres a second,  the Voyager two space probe has taken 30 years to get to interstellar space, and it's not really set up to catch and study dust. Enter the Stardust mission: Stardust was designed to capture comet dust. Thousands of grains were collected, and to examine them the Stardust team created a citizen science project that anyone could take part in: Stardust@home. There were seven tiny dust particles that stood out - and more analysis suggests that these are particles of the dust in interstellar space, that have drifted into our solar system.
Above: The Stardust space probe, not long after it landed. Courtesy of NASA. Again. 
These are the rarest dust particles on Earth. Analysing such rare and easily damaged resource is agonisingly slow, so it'll probably be while before any definite results come out. But, whatever they reveal, Tink can keep her fairy dust: This cosmic dust builds worlds. 

Sorry Tink,...

Elsewhere on the internet:

3D models of explosive star Eta Carina

Eight new planets found - some maybe habitable.

Venus space probe still kicking

Explosion from the galactic core reached 2,000,000 miles an hour

Biggest black hole flare to date detected

Mysterious interstellar molecules mapped

Quantum hard drive breakthrough

Monday, 5 January 2015

Just a quick note...

Above: A nice, blue-because-of-water-and-not-in-any-way-lethal, exoploanet like this one is what astronomers would've liked in their stocking. Not literally though, unless someone's granny has knitted a really over enthusiastically big stocking...
This week is the 225th meeting of the American Astronomical Society - if astronomy is your thing it's well worth following the link to the website and checking out some of the papers there. I'll be picking something ancient solar system related to comment on later in the week, but there're already interesting things coming out about exoplanets and water on them.

Above: The Martian desert, as painted by yours truly.

In news totally unrelated to that: I paint a bit (see above), and I got good feedback when I finally got the guts up to show them to folk. As a result I'm going to start a little blog so people can see what I paint - it's here and I hope you get a bit of pleasure out of it. The collection will grow, albeit slowly at first, as real life is a thing I have to deal with!

Thursday, 1 January 2015

Happy New year! There's a monster in the skies....

No, the title doesn't refer to a terribly hung over Santa who'll dive bomb anyone who makes too much noise. If that happens to anyone it was nothing to do with me. I've been to 'busy' to set up anything like that...

And, while surfing the net hungover, I've come across a paper on something a lot scarier than a drunk Santa*. 

The night sky hides many secrets, and one of them is a cosmic force of god like hunger that'd make Cthlhu wee itself: It's know to astronomers as Sagitarius A*, and it's a black hole. A black hole as big as a small solar system.

Above: A close up view of the patch of sky where the beast lives, courtesy of the University of Illinois.

The existence of this gaping chasm in the universe isn't news. It's swallowed uncounted suns, planets, nebula... that kind of thing leaves subtle signals - like whole stars being pulled toward its maw. But it's 35,000 26,000light years away. That's further than the distance to an open shop when you've had a Christmas day toilet roll shortage. It couldn't possibly affect us, right?

According to this paper, yes, yes it can. Here's the abstract: 

Sagittarius A* Rivaled the Sun in the Ancient X-ray Sky

Sagittarius A*, lying the Galactic Center 8 kpc from Earth, hosts the closest supermassive black hole known to us. It is now inactive, but there are evidences indicating that about six million years ago it underwent a powerful outburst where the luminosity could have approached the Eddington limit. Motivated by the fact that in extragalaxies the supermassive black holes with similar masses and near-Eddington luminosities are usually strong X-ray emitters, we calculate here the X-ray luminosity of Sagittarius A*, assuming that the outburst was due to accretion of gas or tidal disruption of stars, both scenarios having been considered to trigger the previous outburst. We show that in both cases Sagittarius A* could precipitate on Earth an X-ray irradiance comparable to that from the current quiescent sun. The irradiance in harder energy band  surpasses that from an X-class solar flare, and the irradiation 
timescale is also much longer......

To translate some of the science-ese: Sagittarius A* doesn't eat so much as scoff. Very, very messily. The mess of superheated gas it leaves could be as bright as the Sun, as seen from Earth. But not bright in nice visible light, oh no. In X-rays. 

Yep, the same X-rays that're inside the airport scanner. The Scanner you absolutely shouldn't get into and switch on for kicks.
There's a reason why the dentist disappears behind a lead lined wall when he X-rays your teeth: Even small doses of X-rays can be dangerous if they're able to build up over time. If the dentist has to hide from a thirty second dose a  few times a day then imagine the effect a second Sun's worth of X-rays would have had on ancient Earth...

Fortunately, as the paper describes, the beast is currently on a starvation diet. But we know that it's not completely quiet - we can see the effect of its snacking on the surrounding clouds of gas....

Above: The light echoes from the huge black hole's outbursts, caught here rippling over nearby gas clouds, over the course of twelve years. Image courtesy of NASA

If it were more active six million years ago, as the paper suggests, it'd definitely have had an effect on the ancient Earth. But if that's the case then it probably influenced the evolutionary processes that led to us - So we may owe our very existence to the monster in the sky above us.

Observing the way stars, planets, and clouds of gas behave in the vicinity of the giant maw gives us a sort of lab for studying the most extreme conditions warped of space-time: We see gas clouds moving at incredible speeds, and mysterious objects appearing out of nowhere.

It might be a slightly less comforting sky with such a grandold monster in it.

But it's also a more interesting one.

* I only found one thing though.