All posts by The AstroBiological

I come to you from Planet Science, cooking up a tasty stew of words, moving pictures and thoughts aimed at introducing non-science folks to the Universe and all of it's wonders.

Keeping a Lid on Life?

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

Advertisements

Sailed the Ocean Blue

It’s been estimated that a good percentage of planets beyond our solar system may be water worlds.

We here on mother Earth like to think of our blue green marble as a water world. Indeed it is watery, and water is pretty much the reason anything lives here at all. That’s why astrobiologists naturally seek signs of water on exoplanets. “Follow the Water” is a central tenet in the search for extraterrestrial life.

But compared to some worlds, earth really isn’t that waterlogged at all. It’s 0.002 percent water by mass. Only a tiny fraction of that water is available to terrestrial life. That water which isn’t directly involved in biological processes is linked to them, linking life to the planet via seasons and climate.

Some exoplanets are believed to be up to fifty percent water! These are true ocean worlds. To date, up to thirty five percent of exoplanets larger than may be covered by vast layers of water that may or may not harbour life. The jury is well out on that, but the idea is intriguing (and tempting) as the traditional definition of habitable zones is being stretched and reinterpreted.

A water world with a thick atmosphere of steam.

For now, we have only our imaginations with which to explore these worlds…

An aerial view of remote coastline on a hypothetical watery exoplanet.

A new video!

Life in Transit

Interstellar pollution. Free floating organics infused by starlight and beginning their ascension towards life.

Imagination is an important part of science, for without it there would be no curiosity. Here we ponder the theory of panspermia. At it’s essence panspermia is a theory which posits that life on earth (or at least it’s building blocks) came from space. How did it get here? Ancient earth was infected in a sense. Compounds and molecules useful to life were brought here by comets or asteroids and dispersed by impacts.

It is only a theory, but it makes sense in several ways. Recent research gives some credence to it. Decide for yourself. I personally believe that terrestrial biogenesis and panspermia can both contribute equally to debate over the origin of life.

My channel needs you!

https://www.youtube.com/channel/UClvBq6G-DkIlKci7xXdWYzA

Translations

More images.

I’ve been thinking some of these may look good as posters. Thoughts anyone? They provide another way to reach people, as I myself continue to explore and learn about a truly incredible topic.

I like the look and think my channel will finally benefit from a coherent look and vibe. The retro font works for me, and the surreal, fantastic feel of the pictures is my jam.

Channel News

A new video exploring the possibility of directly imaging exoplanets is coming very soon!

Here is a snippet; sans sound or effects just yet!

More coming.

Images of Astrobiology

The universe is turning out to be a more interesting place with each passing day for me. It’s not all about reading research articles and trawling the internet for interesting news in the vast field that is astrobiology.

I’ve been working on images related to various themes in astrobiology. This field really is a playground for the imagination, and it has something for everyone….

Recent news of a relic subsurface biosphere just beneath the surface of Mars…

Our ones and zeroes formed in starlight?

Something really special here: possible traces of limestones found in the fragments of objects orbiting a nearby white dwarf star…

 

Differing definitions of the Habitable Zone further push the limits of life in the universe..

Svante Arhenius, a swedish chemist and early pioneer of the theory of panspermia..

Ruminations on the code (codes?) that make life possible. How many languages does life have in the Universe?

Does the chemical rich, pitch black seabed of Europa host life? Does that of Enceladus?

 

The first image I created. I hope you’ve like these. There will be more! By the way, the background for this image comes from an online simulator called Goldilocks, by Jan Willem Tulp. His work can be found here. It’s really cool.

Ganymede’s Magnetic Mysteries

From an article in Planetaria, a fantastic blog exploring alien worlds, and my new go-to source of news!

Jupiter’s moon Ganymede is found to be producing some exceptionally strong electromagnetic waves. These waves are known as “chorus waves”, as they can be converted into sound, which we would hear as a series of bizarre chirps and whistles. In fact, they sound like an over caffeinated R2-D2!

The universe talks to us!

Ganymede is the second largest moon in the solar system after Titan, and is larger than the planet Mercury. One of the four Gallilean moons, Ganymede’s magnetic field is internally produced, unlike that of it’s sister moon Europa, whose field is induced by Jupiter’s powerful magnetic field.

This magnetism is the result of a highly differentiated internal structure. This means that like Earth, Ganymede has an active molten core, which interacts with upper layers, and also results in the presence of a subsurface ocean. Earth’s magnetic field is the result of it’s molten core and convection of molten iron and rock through the lower and upper mantle. Ganymede has a similar field but it weighs in at a million times stronger than our own! It’s even more intense than the magnetic field pumped out by its parent Jupiter!

This field results in the generation of powerful auroras, which are a familiar phenomenon on earth.

Ganymede’s complex structure is thought to be the result of a fairly quick formation period. During the formation of the solar system, Jupiter ( the oldest of the planets) was still an accreting cloud of gas and dust: a mini nebula much like the solar nebula forming around it. Within this Jovian nebula dozens or maybe hundreds of smaller worlds were accreting: emerging from the primordial Jovian cloud. Proto-Ganymede accreted quickly, within about 10000 years, and so it’s various layers were unable to disperse and homegenise within the moons structure. This can be inferred from the structure of other Jovian moons such as Callisto, which are shown to have an extremely homogeneous internal composition; indicating a more protracted period of accretion and formation. Most likely on the order of about 100000 years.

Jupiter displays impressive aurora as well. These are the result of interactions betweens it’s magnetic field and charged particles issuing from the highly volcanic moon Io.

Aurora and magnetic phenomena have been observed on exoplanets, in particular on mysterious objects known as brown dwarfs. These “failed stars” are quite common in the galaxy, and present a magnetic laboratory for astrobiologists and planet hunters. They are of considerable interest in this context, as they present an opportunity for researchers to examine an atmosphere that resembles that of both a star and a gas giant planet, all without the pesky glow from a nearby star!

Methods of detection and analysis of exo-magnetic fields such as these will not only aid scientists in understanding the formation of planets and stars, but also in the detection of exoplanets, and assessment of their potential habitability. Remember, life on Earth is protected by our magnetic field, so detection of such fields around exotic new worlds could be a hopeful sign.

Thanks for reading AstroBiological, giving you the universe in plain human. I hope you’ve learnt something today. I know I have, and that’s what it’s all about!
I’ll see you next time!

Find out more:

My facebook group:

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

Gone

Yesterday a little light went out from the world. My father in law, Joseph Abela passed away in his sleep.

Joseph hailed from the tiny speck that is Malta; an island nation that has weathered countless storms over the course of its long history. The earliest European civilisations inhabited the archipelago, which sits a stone’s throw away from Italy. Malta has been invaded, attacked, occupied, enslaved and conquered more than its fair share. Through all of this it has persisted. All I can say is these Maltese are tough cookies.

Even now Malta holds its head up high as a tiny but prosperous member of the European Union. A genuine jewel of the Mediterranean I intend to see it one day.

Joseph exemplified the stubbornness that has kept this nation going when all hope has seemed lost so many times. Even during the end, as his life eventually drained away he was fighting: unwilling to give a single inch of ground.

I tell you what, he didn’t care less about political correctness either. He was fun.

Science in recent decades has lost something. It’s headed along a progressivist path, trying to reduce all of human experience and history to nothing more than quantum quirks. Standing with Joe’s large family was a moving experience. Science would like us to believe that we are not much more than collectives of cells, acting as one. Yesterday I saw something more. A life was ending. Experiences, stories, arguments, knowledge: collected over a lifetime of punishment and adversity was fading away with each struggling breath.

When a priest came in and administered Last Rites, I observed something else taking place. As relatives recited prayers and blessings and the priest gave sacraments I saw what human beings have become and are capable of. We are not bags of cells, sloshing across a rocky planet in an indifferent universe. We are stories. We create beauty when we perceive simple things. Emotion, meaning and wisdom have emerged from millenia of evolution.

We are far more than the sum of our parts. In this way emergence is creation.

Joe and everything he was ultimately emerged from the firmament, and yesterday, in a kind of reversal, he reentered the slipstream.

Rest in Peace.