Sometime in the early 2000s, this place was still a speck of data in some astronomers brain. The announcement of a system of seven earth-sized planets was pretty big. The further revelation of three of those worlds sitting within their stars habitable zone was the icing on the cake.
As the first intelligent explorers approach TRAPPIST-1e, we present to you these images: the culmination of decades of waiting, hoping that return transmissions from the TRAPPIST-1 mission wouldn’t get lost in interstellar space. There were those who worried that anything beamed back by the missions wouldn’t even make it out of the system. TRAPPIST-1 is a red dwarf star: a tiny relic of a thing but incredibly ancient. Age estimates range from 8 to 12 billion years old. Red dwarf stars tend to be nasty little suckers, and TRAPPIST-1 is no exception. Extreme solar flare activity sometimes hits the system, as the parent star has a tantrum. Communication from the system is nothing short of a miracle. Nevertheless, here are some of the better images we’ve managed to glean from the stream of data being sent back. Thirty nine years worth. Thirty nine years of waiting.
Approach: A New Red Planet
The very first direct images of TRAPPIST-1 and it’s rocky retinue were messy little blobs of pixels.
Of course, many exoplanets (and exomoons) had been imaged directly using a variety of techniques. The use of coronagraphs to scrape together images from points of light across impossible distances was revealing new vistas for a long time. The following image was taken all the way back in 2004:
A disc of debris around the red dwarf star AU Microscopii. Image: Hubblesite.org
Of course, progress marched on, and as missions approached the system the world waited for new images. A first blurry image sped across the galactic neighbourhood:
This image was a first test. As the mission approached the system, we began seeing more. High quality imaging was held off until final approach, in the interests of energy efficiency.
An infrared and monochromatic direct light image, taken from a distance of approximately 11 AU. Images: Ben Roberts
TRAPPIST-1e was waiting for us.
Imaging of exoplanets is explored in a new video, presenting the concept of coronagraphy. Help astrobiology reach the world (this and others) by checking it out. Subscribe and share if you like.
This post is the first of a series taking us on a trip to a real alien world, and speculating on just what it could be like, using real world astrobiology. I hope you like it!
I’ve been working on some more astrobiology art. It’s taken on a life of its own, and I have to say, I’m paying more attention to these images than my YouTube channel!
I’ve been enamoured lately of dead or dying worlds. A recent video on my channel talked about the amazing possibility of limestone fragments orbiting the white dwarf star SDSSJ1043+0855. Ever since reading of this it’s captured my imagination. The notion that life has existed long ago, possibly before life began on earth bears thinking about.
Limestone is a mineral produced primarily by organisms which produce shells, using a matrix that incorporates calcium carbonate. In the early days of multicellularity, as the predator-prey paradigm took hold of Darwinian evolution, an ancestor of today’s molluscs discovered how to make use of an upsurge in calcium levels in the oceans. It used it to produce a protective suit of armour. This trick was so successful that molluscs became incredibly abundant. So abundant, in fact, that their remains ended up as vast deposits of limestone.
To the present day.
Using spectroscopy, the three elements that comprise calcium carbonate: carbon, oxygen and calcium have been detected in the upper atmosphere of this particular white dwarf. By themselves they aren’t a smoking gun. It’s also fair to point out that limestone can form abiotically. Limestone deposits in subterranean caves are one example. However, the vast majority of limestone on earth is biologically produced.
The “limestone” orbiting this star is believed to be embedded in the fragments of a large rocky object. We know nothing about this world, only that it probably existed and (possibly) limestone comprised part of it. Is it a fossil, spotted across the light years by modern humans? How long ago did this world harbour life? White dwarf stars (which aren’t technically stars! Find out why here) have been discovered which are nearly as old as the universe.
Earth is 4.6 billion years old. What of the world currently being torn up by the immense gravity of this white dwarf?
It would be interesting to look forward and see how our own world eventually will die. For now, this white dwarf star and it’s companions are a way to look ahead at what may befall us. It’s believed that eventually the earth will become incapable of supporting life, as the sun begins to undergo senescence billions of years from now. What iterations will the terrestrial biosphere take over such a vast stretch of time? Will life start over? Are these “fossil” fragments within this unnamed rocky world pieces of its last ecosystems?
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 itselfexpands 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.
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.
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.
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.
For now, we have only our imaginations with which to explore these worlds…
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.
“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.
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 400activevolcanoes! 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 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!!
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!
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!!
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,