The Lost Moon

astrobiology, astronomy, sciart, scicomm, solar system

Boom. Image: Ben Roberts

The moon is one thing we all have in common. I’ve always loved looking up at it. Whether it’s from a religious, mythological or scientific perspective, Luna holds a powerful mystique regardless. The story of the moon is written into the story of life itself.

What does the colossal impact taking place in the above picture have to do with the moon? Because it’s likely the moon formed via a process of accretion.

Around four and a half billion years ago, earth itself had only just coalesced from a cloud of gases and dust that eventually gave rise to the entire system.

Image: Ben Roberts

Earth is believed to have formed without a moon. In fact earth as we know it today formed as a result of the moon.

Picture this. Earth is newly formed. It’s a toxic planet with vast tracts of it’s surface covered by a magma ocean.

Image: Ben Roberts

From the outer solar system it comes. An object roughly the size of mars slams into Earth 1.0. The object has been named Theia. This impact is catastrophic, essentially tearing away the outer surface of our world.

Image: Ben Roberts

Where does all of this crust go? Into space, forming a ring around the newly resurfaced earth. It is this ring, consisting of the fragmentary remains of both our world and Theia, that will accrete to form the moon.

That’s the moon in a nutshell. It’s influence on the course of life has been fundamental, with a critical role in climate and seasonality via the key role it plays in tides. For over four billion years the moon has stared down upon the world, seeing the march of life with all of it’s ups and downs.

Has the moon itself been lifeless all this time? It’s been our closest neighbour for practically forever. We have always thought of the moon as a dead, hostile place. Today it certainly is. With no atmosphere to speak of, negligible water and lethal solar radiation bombarding it’s surface, the consensus of opinion is that the moon is completely devoid of life.

Image Credit: NASA/GSFC/Arizona State University

But it may not always have been like this.

It may be a stretch, but several studies have suggested that at least for a time the moon may have been at least habitable. Perhaps not an oasis of life, but a place that could harbour it.

The moon may not quite have looked like this, but volcanic activity (seen on the limb) would definitely have contributed atmosphere. Images: Ben Roberts

How is this viable? As noted, we all know the moon is hostile to all life. However, the moon is now an inert world, devoid of any geological activity.

Once, though, the moon was anything but inactive. In the period after the moons formation, around four billion years ago it was highly volcanically active.

A habitable moon more likely looked something like this. Image: Ben Roberts

Intense volcanism can be a source of atmospheric gases. This is definitely a factor on earth. Many atmospheric gases, including several trace greenhouse gases are pumped into our skies by volcanoes. Greenhouse gases are pivotal in regulating climate on earth. On the moon all those billions of years ago, volcanoes may have done something similar, bulking up the lunar atmosphere and enabling this tiny world to retain some heat. In addition, a thick atmosphere provided protection against solar radiation and an environment amenable to liquid water. Water is, as we know, crucial to all life on earth. “Follow the water” is one of the central catch cries of astrobiology. Find water, the reasoning goes, and life may be there.

This isn’t always the case though. Water exists almost everywhere in the solar system. There is even water vapour on the sun! There is plenty of water on the moon, locked up as ice in several craters in permanent darkness.

How would all this water have arrived on the moon? Prevailing theory regarding the origins of earth’s water held that much of it was delivered by cometary impacts. This is certainly reasonable. Recent discoveries though hint at vast reservoirs of water locked up deep within the planet itself. Water may be replenished over the eons by outgassing from volcanoes for example. This could have happened on the moon. Several studies of lunar composition have demonstrated that there may be similarly vast amounts of water locked up within the moons core. The ancient moon may have gained a thick watery atmosphere from centuries of volcanic activity partially terraforming it.

So, to put a long story short, water by itself is no guarantee of habitability. The moon, however, may once have been a very different place. With a thick atmosphere providing protection from cosmic rays and allowing pools of liquid water to form, life could have quite easily gained a foothold there. Most likely this life was in the form of unicellular organisms which may have arrived via lithopanspermia. This is a process whereby worlds at close proximity can exchange life or it’s building blocks via impact or volcanic ejecta.

Lithopanspermia: is it a thing? Image: Ben Roberts

This very concept is being applied to crowded systems of exoplanets such as the TRAPPIST-1 system, and is an exciting avenue to explore. In such a system, the possibility of interplanetary ecosystems could exist! This is, of course, very theoretical, but damn what an interesting idea!

What do you think? Was the moon ever habitable?

While you’re at it, check out my tiny little YouTube channel, giving you the universe in plain human!

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Keeping a Lid on Life?

astrobiology, astronomy, scicomm, solar system

A comment on a facebook post I put up a few days ago got me thinking about habitability. Moreover, I got to thinking about the parameters of habitability.

We think that life here on earth is fragile, holding on to a thin silicate crust within a fairly narrow range of temperatures and conditions. For the most part it is. Life needs a fairly stable environment in order to keep on keeping on. However, there are plenty of examples of oddballs: extremophiles, that seem to do quite well in some pretty horrible places. The recent discovery of Antarctic microbes that derive energy from air itself expands the catalogue of organisms that could have analogues on other worlds.

Now, extremophiles do well in extreme environments. No brainer there, and there is no shortage of extreme environments in our solar system alone.

Venus is an example, and a good one. Analogous to Earth in size, density, gravity and composition, it differs markedly in others. No magnetic field, no water (at 0.002% of the atmosphere not worth mentioning), surface temperatures that melt lead, and atmospheric pressure ninety two times what we’re used to here. It’s horrible.

Why?

No plate tectonics. On earth we slowly sail about the globe on slabs of continental crust, which happen to be more buoyant than the thicker, denser oceanic crust. Driven by convection of magma in the mantle, crust is slowly pushed hither and thither by tectonic processes such as seafloor spreading.

To understand what this is, imagine a pot of something thick like soup or porridge on a stove top. As the contents of the pot heat up they begin to stir. Have you ever noticed when this begins to happen that as the surface begins bubbling the top layer is forced aside as new material wells up from below? This is seafloor spreading in a nutshell. Magma from within the earth wells up, heated by a radioactive core, and pushes the seafloor aside as it breaks through, forming new crust. The continental plates, perched atop this moving crust, slowly journey across the planet.

Why is this so important to life on Earth? Because our planets interior is so hot, plate tectonics (along with volcanism) is the primary means by which excess heat is released over time. If this didn’t happen, well, you wouldn’t be here reading this and there would be two Venuses in our solar system instead of one.

Venus, or any one of billions of hellish worlds in the Galaxy? Studying worlds like this gives us insights into life here on earth, because it shows just how unlivable other places can be.

For reasons unknown, Venus shut down. It’s core stopped spinning, it’s magnetic field dwindled to nothing and radiation from the sun began a process of stripping the planet of water. Water is a true miracle ingredient. Not only is it a solvent for biological processes, it’s also a lubricant for plate tectonics. Venus seized up and overheated: exactly like a car without oil will do.

A stagnant lid world is one which has no plate tectonics. Climate is seriously affected by such a situation. With no means of escape, heat builds up within, and eventually it becomes an exo-Venus: scorching hot.

Researchers looking at the issue of habitability on exoplanets have looked at the implications of a stagnant lid regime for the possibility of life. Whilst it would obviously be different to life on earth, other factors can lend habitability to a planet.

These other possibilities are exciting indeed. I’ve been exploring astrobiology through images, producing a bunch of pictures. They will be appearing over the next few posts, so I hope you enjoy them. They’re doing well on Instagram!

Thank you for reading the ramblings of a space nerd. The universe is just too intetesting to ignore.

Talk later!

P.S.

Check out my channel!

All images: ©Benjamin Roberts

Planet Building: Possible?

astroarchaeology, astronomy, scicomm, science fiction, Science fun, solar system, Uncategorized

If you don’t want to read, then listen! I have put this post up on a podcast I’m doing, available on Anchor FM, as well as certain other outlets.

https://anchor.fm/astro-biological/embed/episodes/Planet-Building-e1ff39

If anyone has read “The Hitchhiker’s Guide to the Galaxy” quadrilogy they would have been struck by some of the big ideas hidden within Douglas Adams’ deadpan humour. One of the heavy concepts that stuck with me was the idea of planet building. According to the story, Earth as we know it today is a planet sized super computer, built to perform one task: to figure out the meaning of life. A planetary architect named Slartibartfast is entrusted with overseeing the rebuild of Earth after it’s destroyed due to a galactic scale clerical error.

space-3288275_1920.jpg

Planet building.

Possible? Why not? According to prevailing theories, planets mainly form via the process of accretion. Simply put, particulate matter adrift in molecular clouds clumps under the inexorable pull of gravity, forming ever larger clumps that clump to ever larger clumps and so on. Eventually a planet or star is the inevitable result.

A newly formed exoplanet (in the dotted circle) orbits a newly formed, newly discovered star: CS Cha. Image: Space.com

Why couldn’t this be done artificially? Would it be even possible? If it’s just a matter of throwing lumps of crud at other lumps of crud and hoping they stick, then why couldn’t it be?

screenshot_2018-02-25-09-15-04-07372071793.png

Scenario:

It’s the future. Humanity lives and works in space. The asteroid belt is the new frontier or wild west. Chunks of formerly useless rock are now homesteads or villages. Distances are not overly tyrannical. An asteroid is typically only a few light seconds from another. However, asteroids can be moved. Bigger asteroids like Ceres, Vesta or Eros would comprise the main hubs of commerce and trade in this new world.

8319c21e-27f2-459c-b146-f61ab5ef829d

A new frontier… Image: Maciej Rebisz

Smaller settlements such as these “homesteads” could make life easier for themselves in terms of travel times (and therefore fuel costs) to larger, more important settlements by moving closer. In the frictionless, zero gravity environment that is space this wouldn’t be too technically difficult.

Scenario:

Time has moved on. The asteroid belt is a thriving collective of trade networks and conglomerates of smaller settlements. Smaller asteroids now cluster around larger ones like space junk in low earth orbit. Economically, this proximity is making things easier for everyone, and lots of people are getting rich.

Just imagine though if humans disappeared. The zombie apocalypse hit outer space and spread to all corners of the solar system.

(That’s the fun explanation)

Every living human is gone, and the asteroid belt is now a vast ghost band, forming a wreath around the sun, somewhere between Mars and Jupiter. There are all these swarms of asteroids now adrift, all artificially brought closer together by generations of enterprising human beings No course corrections keep them from colliding and so many of them are doing just that. Orbits decay, and tiny chondrite specks plough slowly into larger planetesimals.

See where I’m going with this? Over time, natural accretion would naturally lead to planets forming, or at least a large moon sized object. In millions of years the solar system could have a tenth planet (let’s just sneak Pluto back into the club. Don’t tell anyone!)

Planet Building! Essentially a garbage planet could form from the artificially placed asteroids and other objects now in very close proximity and drawn by the slow but inescapable pull of gravity.

I think it’s an exciting idea: a real megastructure! The ultimate megastructure!

What next?

This post was inspired by a chance statement in a video discussing space colonies on Isaac Arthur’s Science and Futurism youtube channel. Check it out. Isaac has a huge catalogue of lengthy discussions on some really interesting concepts. Here is a link to the relevant video if you’re interested:

Last but not least, here are links to the social media for Maciej Rebisz, the talented artist behind some fantastic space artwork, including the asteroid colony about halfway down the post.

facebook – https://www.facebook.com/maciej.rebisz

twitter – https://twitter.com/voyager212 – general updates

artstation – https://www.artstation.com/mac – art

society6 – https://society6.com/macrebisz – prints

Join me on my facebook group:

https://www.facebook.com/groups/AstroB/

And on YouTube. I’m not quite up to the standard of the venerable Mr Arthur (yet), but I’m working on it. Help me on this journey and subscribe!

http://www.youtube.com/c/BensLab

Exploring Titan: a Channel Update

astrobiology, scicomm, Science fun, solar system, Uncategorized

My tiny little channel lives! I’m almost at 200 subscribers.

UPDATE: 3rd APRIL 2018

200 Subscribers!

Back to the post.

That is peanuts, but it tells me this channel is definitely trending on an upward trajectory. My most recent video “A Brief History of Astrobiology” is doing well (hint, check it out!)

Watch it for an irreverant look at astrobiology over the ages.

My next one will take a closer look at Titan through the imaginary eyes of its discoverer; Christiaan Huygens, the Dutch astronomer who spied this mysterious moon in 1655. I plan on taking Huygens there for a grand tour. He may even meet his namesake!

huygens_astronaut

What would a 17th century stargazer think upon seeing his high tech namesake, at rest on a frozen plain on Titan?

The tale of Huygens incredible discovery, as well as his amazing mind is worth a single video, and so that’s exactly what this new one is, the story of the exploration of Titan, from 1655 up until some imaginary mission sometime in the late 2020s, when a drone flies through the thick soupy atmosphere of this exotic moon. Maybe (just maybe) a submarine will explore the methane seas that dot the moons northern expanses. I personally can’t wait for both to happen.

Titan boasts liquid hydrocarbon lakes at its north pole

This would be quite a view.

Here are a few screen shots from the upcoming video:

titan drone flight.00_04_24_12.Still005

A drones eye view of titan, seen through a veil of organic haze and interference.

titan drone flight.00_02_49_16.Still004

The drone takes wing, dropped into the atmosphere of Titan. One of the mysterious methane seas can be just discerned through the haze coating the landscape.

titan drone flight.00_05_00_11.Still006

A night time flight over a methane lake. Beneath the frigid surface a small submarine drone looks for signs of methane based aquatic life.

I’m super excited about this one, and I am sure it’s going to be a lot of fun. Stay tuned!

Ben.

16 Psyche

astrobiology, astronomy, scicomm, solar system

My newest video features the bizarre metal asteroid 16 Psyche. This improbable chunk of iron and nickel may one day be mined, yielding metals worth over 10000 quadrillion dollars! No, that figure doesn’t seem real to me either.

Here is the transcript for said episode. I had some fun experimenting with effects for this episode, and I think it works well!

“G’day metal heads!

Do you think you’re rough and tough?

Do you believe you’re made of metal?

hah!

See if you can outmetal THIS monster! A ball of metal mayhem 200 km across! Let’s go check out 16 Psyche!!!

Long long ago, in a molecular cloud not so far away….

The Solar System: Episode 1

It is a time of turmoil in the newly formed solar system. Planets, moons and other heavenly bodies have coalesced from the primordial cloud. As larger bodies fall into orbit around a blazing new sun, smaller worlds are caught up in a system wide spree of destruction known as the Late Heavy Bombardment.

It is a perilous time for a planetesimal or moon, and many smaller planets are destroyed in the cataclysm.

A lone youtuber known as Ben has ventured out into the Big Empty, to visit the long dead core of one such world. Upon reaching it, he sends in a gallant drone to investigate….

Yes Sir! Here we are. Welcome to 16 Psyche. An oddball world really. This place is special for a few reasons.

Discovered in 1852 by the Italian astronomer Annibale de Gasparis, 16 Psyche was named after Psyche, a figure from ancient Greek mythology. The word itself means “Soul”.

16 Psyche is pretty big: a ball of metal over 200 km in diameter! It’s almost entirely nickel and iron to be more precise, although about 10 percent of its surface is strewn with silicate rock much as you’d find here on good old earth.

So this ball of tinfoil from hell comprises nearly one per cent of the mass within the asteroid belt where it lives. It actually lies roughly halfway between Jupiter and Mars, about 3.3 AU from the sun.

What’s an AU?

AU is a very common astronomical term. It means “astronomical unit’. 1 astronomical unit is defined as the distance between Earth and the Sun. This is about 93 million miles or 150 million kilometres. At 3.3 AU this means 16 Psyche lies some  308 million kilometres from the Sun.

Wanna know what’s really special about this metal asteroid?

Two things.

First of all, 16 Psyche is extremely valuable. All of that iron and nickel within has been valued at over 10000 quadrillion dollars!

Obviously that means a lot of folks would love to mine it for all that metal.  A whole bunch of companies have sprung up in the last few years, looking to cash in on asteroids: the next big thing!

Personally, I don’t care about all that. You wanna know what’s really cool about 16 Psyche?

It’s the exposed core of a long dead protoplanet; the remains of a tiny world maybe 500 km in diameter. This tiny planetoid took a beating during the Late Heavy Bombardment, some 4 billion years ago. In fact, this nameless world may have been impacted by other large bodies up to 8 times. This pounding shattered the outer crust, sending scattered fragments out into the newly forming asteroid belt and leaving behind an exposed core. Scientists would love to study 16 Psyche, because it can teach us a lot about planet formation and how planets work- including our own.

Just look at it!  Imagine walking on the core of a planet. 16 Psyche gives us an opportunity to see into our own world in a way. It’s like a time capsule: a snapshot of a newly forming planet, frozen in time for ever.

This is the real value of 16 Psyche, this frozen soul. Let’s take one last look and imagine actually being there….

Outro!

I hope you’ve enjoyed watching this episode. It was super fun to make, and if you got something out of it, then subscribe to this channel for more. Join the astrobiological Facebook group, find me on Twitter. Links in the description.

AstroBiological: giving you the universe in plain human. See you next time!”

Europa: Life Beneath the Ice?

astrobiology, astronomy, Biology, Biomolecules, scicomm, solar system

The Chicken and the Egg

 

There’s an old theory known as Panspermia,  which hypothesises that life got its initial leg up on Earth (around 4-3.5 billion years ago) after a long journey across space. According to this theory, (which at the very least is quite reasonable) the ingredients and precursor molecules for life hitched a ride on comets and asteroids and reached earth early in its history, when these objects impacted our planet. As for where these molecules and ingredients came from…well, that is a real chicken and the egg type question, and one I will be exploring in more detail in future posts as well as videos.

Not all astrobiologists agree with this of course. Each to their own. Science and seeking the truth is all about disagreement. I’ll leave the debate alone and for the purpose of this post assume that Panspermia is a pretty valid idea.

Screenshot_2017-09-11-12-58-26-1

You said it Neil. Funny thing is, look at all the people agreeing with him. Kinda ironic?

 

This post (and the YouTube video it will eventually give birth too) is essentially a piece of speculation. Looking into the future of space exploration, what is waiting for us out there?

Europa has been the hearts desire of many an astrobiologist for decades now. Ever since the Pioneer 10  probe rushed past back in 1973 and sent back the first pictures it’s been a bit of a rock star. Why? Because it ticks a whole lot of boxes on the “Things could live here because…” checklist.

Things could live here because….

Let’s look at some of those boxes. And why they’re important. First of all:

1: Europa is  now widely believed to harbour a substantial subsurface ocean: of actual honest to gosh water. How have we come to this conclusion?

Take a look at the surface of Europa.

It sure is striking. Huge channels and streaks criss cross the moons frozen exterior.

And that’s about it.

No craters? Callisto is part of the Jovian family as well, and is the most heavily cratered  object in the solar system. Compared to Europa Callisto is a teenager with weapons grade acne.

Like an explosion in a pizza factory.

Europas surface is geologically new, having been resurfaced recently (in geological terms). Something is wiping the slate clean on Europa, and this is our first clue that Europa is special. Something under that icy shell is acting upon the surface and rearranging it.

Astrobiologists think it’s water. A lot of it. Europas surface is basically a shell of ice, rafting and fracturing like pack ice on Earth. Essentially vast swathes of pack ice remodel the Europan landscape and are thought to be it’s version of our plate tectonics.

 

2: Some time ago, none other than the venerable Charles Darwin postulated that life began in a “warm little pond”, whereby the right combination of mineral salts and energy resulted in the first biomolecules. Ever since this first speculation, forwarded in a private letter from Darwin to his friend Joseph Hooker in 1871, science has placed an emphasis on water as the likeliest birthplace of life on Earth. Darwin believed in a warm little pool, many other theories have thought bigger, fingering the ocean as the culprit. Whatever the case may be, and whatever supporting evidence gives testament to it, water (for now) is the one thing no life can exist without.

And Europa has a lot of it. The deepest point on our planet lies at the bottom of the Marianas Trench, some 12 kilometres below sea level. That is deep to be sure, but the abyssal plains of the world’s oceans are on average about 4 kilometres beneath the waves. Europas subsurface ocean averages a cold dark 62 kilometres deep!

Where do the minerals fit into this? Patience, grasshopper!

Jupiter pumps out extremely high levels of electromagnetic radiation. This is, of course, a constant engineering hurdle for the various missions that have paid the gas giant a visit. It’s extensive family of moons: some 67 in total are constantly immersed in this field, which interacts with various bodies in various ways. Europas magnetic field is no different,  and is an induced magnetic field.  This is a special kind of magnetic field produced when an electromagnetic field is passed through some kind of conductive material. In the case of Europa this material is believed to be an ocean, brimming with conductive mineral salts. Such an ocean would be a vast salty brew, fulfilling Darwin’s vision somewhat.

Europa-magnetic-field.jpg

Europa’s magnetic field changes in relation to it’s position within Jupiter’s magnetic field, indicating it isn’t generated by the moon itself, but is induced by Jupiter.

What of Darwin’s energy source? To understand this a little more, and to see what it means for Europa, we need to understand that all life requires an energy source. On Earth, the vast majority of life is solar powered. What does this mean? You can’t just go outside and photosynthesise! You need to go to the fridge and get a snack. Food keeps you going, right?

Absolutely. But where did that food come from? Whether  you’re a vegetarian or a carnivore, ultimately every single thing in that fridge of yours exists because of the sun. Either it grew from the ground, something came along and ate it, or something bigger came along and ate that something. The sun is at the base of this very simplified food web, and it’s been doing it forever of course.

No solar power is not some fandangled idea. Renewable energy has been around, well, since before life began. The sun provides energy not only for Earth’s climate and hydrological cycle, it also fuels all photosynthesis on Earth. Plant life not only provides food and oxygen for animal and fungal life, it also contributes to climatic processes.  Yes, the Sun is really important.

Ah, you think, how does any of this relate to Europa? The frozen moon is a bit further out from the sun than warm little earth, at about 485 million kilometres. Not much use for solar power out there! Well it turns out that not all life on Earth is completely dependent on the Sun after all.

Enter the hydrothermal vents.

These are exciting and mysterious places, home to a bewildering and diverse array of lifeforms. They are found where life seemingly has no business existing, and yet there they are: on the vast abyssal plains of the ocean floor. Miles away from any sunlight, subjected to pressures and extremes that would kill us instantly life thrives in a hostile alien world.

Champagne_vent_white_smokers

A white smoker, situated at the Champagne Vent in the Marianas Trench, Pacific Ocean. Image: NOAA

These ecosystems are based not on photosynthesis, whereby sunlight is converted into a food source for plants, but chemosynthesis. Down here life has found a way, to steal a phrase from “Jurassic Park”. Literally, bacteria have evolved to survive at the hellish temperatures and pressures around these hydrothermal  vents, where the water can reach temperatures of over 350 degrees Celsius. With nothing but a rich mineral brew spewing from these vents out onto the ocean floor, these bacteria have learnt to make use of this brew. These bacteria then form the basis for some of the most intriguing ecosystems on the planet. These vents are an oasis of life, all alone in the abyssal night.

life-on-europa

Concept art showing the possible structure beneath the ice. Image: NASA/JPL

Does Europa have the capacity for such vents, far beneath the ice? On Earth, the vents are geothermally heated. Earth posesses a core of molten iron, heated by slow radioactive decay of elements from the formation of the planet 4.6 billion years ago. This internal heat eventually reaches the upper mantle of the planet, seeping through in more threadbare regions of the Earth’s crust,  Europa is heated by Jupiter itself. As the moon orbits the gas giant, tidal forces act upon it, squeezing and massaging. Resulting frictional forces are believed to sustain a heated core, which, just like earth, could provide energy to keep systems of hydrothermal vents running on the abyssal plains of Europa.

So. Europa may tick some really important boxes, for the existence of life. Water: definitely check. Minerals and organic compounds: check. A source of heat, to power possible life: check.

Now the only thing for it is to visit; to get through the icy shell to the ocean beneath….

To be continued….

Next post takes a ride beneath the ice.

17th November 2017:

And here is the video for which this post formed the script:

 

Further Reading and Resources

http://geology.com/stories/13/life-on-europa/

https://en.wikipedia.org/wiki/Panspermia

http://www.whoi.edu/page.do?pid=83497&tid=7842&cid=70453

View at Medium.com

https://blogs.scientificamerican.com/thoughtomics/did-life-evolve-in-a-warm-little-pond/

http://ffden-2.phys.uaf.edu/webproj/212_spring_2015/Amir_Raz/amir_raz/Magnetic.htm

https://cosmosmagazine.com/space/hunting-the-building-blocks-of-alien-life?utm_content=bufferc7d0e&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer

View at Medium.com

View at Medium.com

View at Medium.com

View at Medium.com

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

View at Medium.com

View at Medium.com

Extremely Extreme Places in the Solar System

astronomy, scicomm, Science fun, solar system

Hi all. This post is essentially the script for a YouTube episode I have coming up on my Ben’s Lab channel. Like the “Holiday on Venus” episode, this one also is meant to depict a TV or radio presenter, outlining a vacation package across the solar system. Zip on past this video if you like, but it provides a bit of continuity for the script.

G’day, lunatics!

“Do you love risking life and limb? Do you think extreme sports is the perfect way to relax? Well then strap yourselves in! Did you love your trip to Venus! Venus is the testing ground for the Apocalypse! Not for the faint hearted!

If you thought Venus was hardcore, and you’re thirsty for more, Time-X has the ultimate vacation package for you! A grand tour of the craziest places in the Solar System! Let’s go!!!!

Mars! Been there, done that, I know, but have you seen a REAL Grand Canyon! Valles Marineris: the longest Canyon in the solar system! Not only the longest, but the deepest!

Those guys in Norway back in the old days… thought they were pretty cool jumping off cliffs, here, swooping down gracefully in their seagull suits! How do you think they’d like to jump into this bad boy! At 2485 miles long, there’s plenty of parking! That’s the distance from San Francisco to Washington. Or, just a bit more than the distance from Sydney to Perth! Holy Frehole! Not only is this canyon long, stretching a quarter of the way around Mars, it’s deep: 7 km deep in places. Hooley Dooley! Cliff jumpers will go insane for this place!

Should we tell them there’s almost no atmosphere on Mars, and they’ll drop like stones?…..Nah!

Still on Mars!

Enjoy a sunrise atop Olympus Mons. Sounds lovely! At an altitude of 21.9 kilometres! That’s pretty tall! How tall is Mount Everest in comparison? Do we even care? Look, look at the little poopoo! Nawwww!!! Olympus Mons is an extremely ancient shield volcano, which has long since become extinct. Climbing its slope, you’d actually be virtually standing in outer space once reaching the peak! What’s not to like about that?

Moving on… ahem!

Next stop, Vesta, a lovely little chunk of prime real estate in the Asteroid belt. Boasting lots of peace and quiet and some really epic views, Vesta has the tallest mountain in the Solar System: Rheasilvia.

A computer generated elevation map of Rheasilvia crater, with its 20km+ peak at its centre. Image: NASA/JPL.

And from above. Red areas correspond to maximum elevation. Image: NASA/JPL.

Plopped right in the middle of a gigantic crater that takes up 90 percent of the diameter of Vesta, this monster was formed by a meaty impact with something really big and mean around 1 billion years ago. Sorry Olympus Mons, Rheasilvia is just a little bit higher than you, at 22 km.

Let’s head further out! Where are we now?

 Io, orbiting Jupiter, is the most geologically active object in the solar system! Did someone say geology? That doesn’t sound very extreme, you say. What does that mean for the extreme sports nut? Well, Io has 400 active volcanoes! 400! Ride your mountain bike down one of those- there’s no shortage of them! Just ride really fast! This place is a little bit too extreme! I’m not hanging around for that!

We haven’t forgotten water sports! Europa is the place to go for extreme deep sea diving! Back on earth the deepest point in the ocean is the Marianas Trench in the Pacific Ocean, which gets to 12 km below sea level. You could hide majestic Mount Everest inside it. Poor Everest, a little bit inadequate today!

Europa, smallest of the Galillean moons, is a real contender for the possibility of life. Image: NASA/JPL.

Europa orbits Jupiter, and looks pretty serene, but that pretty icy shell hides an ocean averaging 62 km deep! I’d like to explore that myself! Just be mindful though, extreme sportsters; Europa may have it’s own life. No littering and no feeding the natives!

That’s some pretty serious water! On to our next stop: Neptune and Uranus!

If extreme weather is your thing, then line up! Go hang-gliding in these winds! On Uranus, winds in the upper atmosphere blow along at over 900 kph!

Stop the world, I wanna get off!

But wait, there’s more!

On Neptune, similar winds scream along at a brain splattering 2100 kph! Just think about it. Whiplash from hell, anyone?

If you still can’t get jumping off rocks out of your system, then you will LOVE Miranda, one of the moons of Uranus. What’s so great about Miranda?

Only the TALLEST CLIFFS IN THE ENTIRE SOLAR SYSTEM!!

Verona Rupes, right of centre, caught in a single grainy image during the Voyager 2 flyby in 1986.

For some colon twisting thrills, these cliffs fit the bill. At 20 km deep, it’ll be a real high jump! Thing is though, we offer this jump to newbies. Why? Because with Miranda’s tiny gravity, it’ll take 12 minutes to fall to the bottom! You’ll hit pretty hard, at about 200 kph, but a tonne of bubble wrap will get around that! We do give a Seniors discount for this jump.

Well those places are nasty, no doubt, But never let it be said that we at Time-X are not discerning purveyors of the ultimate in bowel clenching excitement!

Let’s leave the Solar system altogether! Hurry up! It’s 63 light years away!

What is?

The perfect way to say “I love you” to the raving psychopath in your life!

Exoplanet HD189733B (Catchy name, I know!)

This place eats the others for breakfast. Uranus and Neptune are super windy, but they’re just farting compared to this place. Winds reach speeds of 5400 miles per hour, or 8690 kph!! Oh my gosh! AND it rains glass!! Sideways!! If you’re still keen to visit, put your affairs in order and say goodbye to your loved ones, because that’s what extreme sports are all about!!

Do you wanna live forever?

Places on this trip are going fast! Mind you, we have a slightly high turnover, so you don’t really have to wait too long for a seat. Call now.

If you love bone crushing science and mind splattering knowledge, subscribe to Time-X , I mean Ben’s Lab! Giving you the Universe in PLAIN HUMAN!”

 

What do you think? Suggestions and comments below! Until then,

 

Ben.

 

References and Further Reading:

https://www.nasa.gov/image-feature/rains-of-terror-on-exoplanet-hd-189733b

https://www.space.com/21157-uranus-neptune-winds-revealed.html

https://en.wikipedia.org/wiki/Valles_Marineris

https://apod.nasa.gov/apod/ap110404.html

https://solarsystem.nasa.gov/planets/io

https://www.nasa.gov/multimedia/imagegallery/image_feature_956.html

https://www.space.com/27334-uranus-frankenstein-moon-miranda.html

Sons of War: The view from Phobos

astronomy, scicomm, science fiction, solar system

The crackling airwaves reverberate with the ethereal radio noise of the universe. You’re sitting cross-legged in fine regolith staring out into the big empty. You reach down and tune the receiver on your space suit, trying to lock in some broadcasts from Mars.

It’s pretty quiet down there today.  Traffic is slow. There sure as hell isn’t too much happening here today. Not even commercial vessels hover over the skyline of this tiny moon.  Phobos is alone with its thoughts on this Martian Sol,  and so are you.

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Come to Phobos! Spectacular views!

It’s a good place to get away. When you’re after some quiet time, you don’t mess around. Mars is a hub of busy-busy, as a melting pot of factions; corporate, government and private explore and carve it up. Maps are being drawn down there, maps of the future.

Mars rolls slowly beneath you. Phobos’ orbit brings it close to the red planet. With a semi-major axis of 9377 kilometres, Phobos makes a closer approach to its parent body than any other satellite or moon in the Solar System. By contrast, Phobos’ little brother; Deimos has a semi-major axis of 23460 kilometres. IF you were standing on the surface of Mars you might just see Deimos as a point of light, something like the folks back on Earth see Venus in the morning and at dusk.

At The Martian equator Phobos is about 1/3 the size of the full moon as seen on Earth.  Artist’s impression.

So, why “Sons of War?”

Asaph Hall, who inadvertently discovered the pair in 1877 after some pushing from his wife (after which Stickney Crater was named), had a penchant for ancient Greece it seems. Phobos and Deimos were the sons of the Greek god of war; Ares! (Mars to the Romans.) Phobos meant panic and Deimos meant fear.

They sounded like a handful for their old man!

The universe is a gift. What else can it be? Every single day seems to bring something new and completely interesting. Sometimes you need to hunt for it, and sometimes it’s right there, hiding in plain sight.  You’ve been known to have a fascination with the phenomenon. You never thought sitting up here on this nondescript pile of rubble could be so interesting. All alone with this incredible vista you look down at Mars and think about tossing your tickets back home out into space. It wouldn’t take much. Here on Phobos you are your own launch system. Phobos is the ultimate destination for weight loss. Back on earth you weigh in at just over one hundred kilograms. Here on this tiny little rock you weigh just over 60 grams! That’s right! You and your little sister’s black and white kitten weigh the same right now!

How cute.

Ha! You’re a lightweight like me! Puny human!

It makes going for a walk tricky though. In the first few years of the Great Mars Rush Phobos was a hotspot. Stickney Crater, that 6 mile wide basin swallowing up one end of the moon became an overnight spaceport, with Hamer Station becoming a sprawl of impossible architecture in a couple of years. People being what they are, didn’t really look before they leapt: literally. Rescuing floating space tourists who’d become new martian moons became a profitable cottage industry. Magnetic boots won’t work here of course. The terrain is almost entirely regolith: powdered rock formed by millennia of impacts. In fact, gravity is so low that with every step you carefully take a cloud of dust slowly puffs up, taking several minutes to descend back to the ground behind you.

You’re holding onto a handrail, one of several hundred which stretch for collectively dozens of miles around the moon. These handrails were the workaround some bright spark came up with in the early days. Straight out of an OH&S* manual, these rails are pretty much all that keeps you from launching yourself into the Big Empty.

Because gravity is so light, you can’t really “feel” the terrain. Probably if you weighed your actual 100 kilos, you’d sink into the several metres of regolith beneath you. It’d be like dry quicksand. Beneath all that are voids; a handy feature of the moon. Phobos is about one-third empty space. It’s a feature of the moon’s formation. Back when Mars was in its infancy something huge crashed into it, like an interplanetary T-Rex.

Space is rough.

A lot of Mars was kicked up into space, forming a secondary cloud of dust and rock around what was left of it. Some of this matter clumped and glommed together, under gravity’s inexorable pull, and moons formed. Phobos and Deimos are the last survivors of these martian offspring. They are piles of rubble. Imagine you’re an extra in a disaster movie, where a building has collapsed on your head, and you play a survivor, trapped in the rubble. All the bits of the building don’t fall down in an orderly manner. This would be an entirely different universe if they did.

Just imagine physics lessons!

Anyway. Survivors, trapped under fallen rubble. Girders, chunks of concrete and twisted metal have fallen randomly, strewn in a completely chaotic heap of mess, under which our film extras wait for the heroic star to pull them out. Phobos is like this. Chunks of randomly shaped Mars have simply fallen together, resulting in an odd honeycomb of dark empty caverns and spaces; now used by humanity, which is rapidly filling them up with the detritus of colonisation and industry. Even living quarters. Like some bizarre sentient ant colony humans hide underground here. It’s a refuge from some crazy space radiation, the same as that bombarding and frying electronics down on Mars.

Mars is virtually zipping past. Phobos has an extremely fast orbit. Right now you are sailing around the red planet, completing an orbit in just over seven hours. Deimos, all alone out there lags behind, making the journey in just over thirty hours. You’re holding the handrail tight, but part of you wants to let go, to reach out for the Red Planet. It really is moving fast, now that Humanity is here.

To paraphrase Kim Stanley Robinson: “Once Mars was a dream. Now, it was a place.”

Valles Marineris, the longest and deepest canyon in the Solar System. Stretching away into the future, like a new Wild West.

The Japanese Space Agency is currently putting together a mission to not only explore the moons of Mars, but to return samples to Earth. Good luck guys. Follow them on Twitter to keep up with their progress and mission updates:

 

 

*Occupational Health and Safety

Water, water everywhere

astrobiology, scicomm, solar system

So. We exist here on our rock, as it flies around our medium size main sequence star, and slowly but surely begin to realise that we are not quite as special as we think. Sure, we’ve come a long way. This isn’t necessarily a good thing. Progress is literally a moving forward. By this rationale the human race has made astonishing progress in the last two hundred years. I won’t rattle off the myriad achievements we’ve ticked off the sentient species bucket list, but we’ve done a lot- let’s just leave it at that. The mobile device or computer you’re reading this post on is one tiny part of that progress.

But one piece of wisdom we have gained in the midst of all this gadgetry is this:

We are not the centre of the Universe.

There. I said it.

Ever since Copernicus, Gallileo et al realised that Earth revolves around the Sun, much human progress and thinking has revolved around the fact that no, we are not the focal point of creation, life has gone on before us (and will carry on long after we’re gone), and that our very planet is turning out to be not quite as unique as we thought.

It seems like every second week a new exoplanet is being discovered and added to a growing bestiary of worlds. Most of those worlds are nothing like earth: but I believe it’s only a matter of time. In our own solar system water; that miracle ingredient for the appearance of life is turning up everywhere we look.

Water is a bit of a superstar. I won’t espouse it’s virtues here, but suffice to say, absolutely no life (as we know it) can exist without it. Water is turning up everywhere it seems. Here are a few examples. I will begin this tour with with the inner planets of the Solar System. For the sake of brevity I will only glance on each location. At this point in time current thinking is focused on certain moons in the outer solar system: “outer” meaning beyond the asteroid belt. Water appears to be abundant as we head outward, but I think it fair that the terrestrial planets get some love too. After all, should humanity  ever sort out its myriad problems and eventually stops just dipping it’s toes in the water, one of these worlds might just be a new home for our species. The presence of water would be highly advantageous.

Let’s put together a little list of locales in the Inner solar system where water is thought to exist. I will include Earth here as the first obvious example.

Earth

Home to over 7 billion talking monkeys, loads of beetles, bacteria and a whole pile of other beasties all jostling about on the Tree of Life. A middle aged planet, third from it’s parent sun in a non-descript solar system moving quietly through the Orion Arm of the Milky Way Galaxy. There’s a lot of water here, about 1,260.000,000,000,000,000,000 litres. That’s 1260 million trillion litres.

Now, obviously that sounds like a lot, but if you want to really get an idea of how much water this is, just ponder this. Of all water on earth, 96% is saline. Four percent exists as freshwater. Of this four percent, sixty eight percent is locked up in ice and glaciers. Thirty percent of the remaining freshwater is groundwater, and thus not accessible to all and sundry.

About 0.006 of this four percent exists in rivers and lakes.

0.006 percent!

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This tiny sliver of the total global water pie keeps all of us talking monkeys alive.

So, where  is this going?

There are vast amounts of water on Earth. But Earth is only one of 8 other planets in the solar system. There are also five dwarf planets, of which Ceres and Pluto are the most famous examples, and 182 moons orbiting various objects and bodies throughout the solar system.

The Sun

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Huh?

Say again?, you ask. “Ben, are you out of your gourd? Isn’t the Sun that great big hot thing at the centre of the solar system? You know, that really hot thing that is so hot we can feel it’s heat here, from 93 million kilometres away?”

Yes, Dear Reader, the sun is that big hot thing. But researchers have demonstrated the existence of water vapour in the central cooler regions of sunspots. Apparently, so the science goes, these regions are just cool enough that hydrogen and oxygen can get all chummy and form water. Now, liquid water (and obviously ice) are out of the question, but there you go. There is water on the sun. Next.

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Mercury

Poor old Mercury has never had a good trot. The closest planet to the sun, Mercury got baked clean millennia ago. No atmosphere worth mentioning exists, and so you’d think that’d be it. It’s just a barren hellish wasteland. Right?

2017-02-02-1.png

462 degrees in the shade.

Wrong.

Like all of the inner planets, Mercury has taken a thrashing from impacts over it’s sad history. It skims around the sun pocked with craters. Some of these happen to sit right on the Mercurian Terminator. A terminator is not a killer robot with poor acting skills. A terminator is simply the demarcation where the planet’s daytime side meets the night time side.

This means that some of these craters contain regions draped permanently in shadow. Similar  craters exist on our very own Moon, and yes, water ice has been observed in them! These ice filled craters are being touted as a bit of a sweetener for permanent human habitation on ol’ Luna.

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Similar shadow filled craters have been observed on the Moon.

Alas, Mercury doesn’t have much else going for it. It completely lacks a magnetic field, and lost whatever atmosphere it ever had long before Eukaryotes began crawling around.

Say you were an alien visitor to our solar system. Imagine yourself flying in: past the gas giants (what’s with that big red spot?), past all those pesky asteroids (that weird metal asteroid warrants a second look!), even past that blue green marble, with all the chatter pouring out on the electromagnetic spectrum. You keep on flying. It’s been a long flight, but there are two more planets to look at. This next one looks liks a big deal!

Venus

As you approach Sol 2 you’re thinking this place seems like Sol 3. Gravity is pretty similar , and it’s about the same size. There are even clouds here: lots of them!

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Venus was once…almost idyllic?

Oh. It’s time to stop using your eyes and switch on some of that fantastic alien technology of yours.

Sol 2 isn’t so nice after all. In fact it’s downright awful. Some sort of disaster has befallen this planet. No magnetic field, atmospheric pressure that will crush your delicate little  space gazelle should you ever choose to land and temperatures that can bake cakes.

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There is water here though! Thick choking clouds of carbon dioxide and sulfur enshroud the planet, but there are traces of water in the atmosphere! It’s only 0.002 percent to be sure, but it’s there.

Your space gazelle (translation: extremely sleek and advanced spaceship) has beauty AND brains. Scans show hydrogen and oxygen ions trailing out behind the planet, and you realise that water loss is an ongoing issue for Sol 2. Solar winds have been slowly stripping Sol 2 of water for a long time; maybe billions of years, leaving this hellish dessicated planet behind. It’s a pity, you figure. Sol 2 would have been nice once. Sol 3 beckons as a potential home sometime, but the natives are barking mad. Looks like rolling in and blowing stuff up might be the only way after all. All that water!

Sol 3 has been studied to death, so you decide to swing around and take a look at the Red Planet.

Mars

Dry as a bone. Peaceful to be sure, but this planet is dead. Weighing in at roughly one third the size of Earth, Sol 4 may have struggled to hold onto any atmosphere it may have had.

Of course, being a little guy isn’t the be all and end all. Titan is the largest moon of Saturn. Somewhat smaller than Mars, yet fifty percent larger than our own moon, Titan sports an impressively thick atmosphere: thicker in fact than our own. Unfortunately Titan can be shunned from this article: it posesses oceans…..of liquid methane. No water here folks. I include Titan to demonstrate that smaller worlds can possess respectable atmospheres.

With 15% of Earth’s gravity and temperatures at an extremely frosty -176 degrees Kelvin, Titan is not a viable destination for human exploration just now. But it is more similar to Earth than anywhere else in the solar system…It just doesn’t have any water.

Mars, like Venus, is missing a key component here. Earth is the proverbial bowl of perfect porridge; just right. Many features of Earth are conducive to life, but perhaps one of the most important is the presence of an active core. This one feature prevents harmful cosmic rays from degrading DNA so badly that life mutates itself to death. It also prevents said rays from stripping away our water and atmosphere. This appears to have happened on Mars and it’s happening on Venus as we speak.

Does it, doesn’t it?

Mars is turning out to be a slippery customer. Evidence for erstwhile liquid water on the red planet seems to be piling up. It’s heading toward consensus that Mars once was much warmer and wetter than it is today.

Another Eden?

NASA’s Curiosity rover is the closest we’ll get to visiting Mars for some time yet, and it has captured some pure Martian magic on it’s sojourns across the dead and lifeless face of possibly humanity’s first true stepping stone to the stars.

Our descendants may one day take off their helmets and breathe Martian air.

Possibly the greatest aspect of Curiosity is that it is a quintessentially human mission. Human eyes see the surface of Mars, beamed across vast distances and tease out information about this place. One simple photo can convey a lot if you know where to look and what to look for:

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These are synaerisis cracks. They typically form in river or lake beds when water dries up, leaving the mud to crack as it shrinks in this fashion. Whats so special about these cracks? They’re on Mars.

Essentially the general thrust of new discoveries these days is that it’s more likely for water to be somewhere than unlikely. I will end this blog post with new insights into water back here on Earth. As mentioned previously, several moons in the outer solar system are posited to possess vast quantities of water in the form of sub surface briny oceans.

However, it turns out Earth has a few surprises still up it’s sleeve. A diamond ejected around 90 million years ago from a volcano in Juina, Brazil contains imperfections, that, like a seemingly trivial clue in some glossy crime investigation show, point the way to to the one time existence of a subsurface ocean deep in earth’s crust. In fact, this ocean was (is?) posited to have descended nearly a third of the way to the edge of Earth’s core. These clues come in the form of hydroxyl ions, which normally only come from water. More evidence is arising, pointing toward water’s earlier appearance on Earth than expected. I will write about this and similar topics as I am able.

More posts on water in the solar system will be up as soon as I find time to write more. Keep on looking up! The Universe is there. See you next time, and thanks for reading.

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Ben’s Lab.