While our dreams of contact with an alien civilization have traditionally relied on either a direct visit or the reception of an intelligent signal transmitted across the galaxy, these remain long-term possibilities. But real technology could enable us to find worlds where life is abundant and ubiquitous much sooner than we expect based on playing this cosmic lottery. (DANIELLE FUTSELAAR)
Two of our biggest science fiction dreams may not remain fiction for much longer. Here's how 21st century science can make this a reality.
For as long as humans have looked at the stars in the sky, two questions have captured our collective dreams: Are there other life forms on any of their worlds, and will we ever be able to fulfill the dream of traveling to one of them? ? While both tasks appear to present extremely daunting technical challenges, recent advances in science suggest that not only will humanity be capable of overcoming them, but we may even be able to do so later this century.
While faster-than-light travel and visits from aliens – whether benign or malevolent – form the basis of our science fiction stories, it is plausible that our real-life scientific advances are legitimately deeper than any fictional stories people imagine. . Located on the edge of both borders, humanity may be on the verge of realizing a dream as old as humanity itself.
A logarithmic distance chart showing the Voyager spacecraft, our Solar System, and our nearest star for comparison. If we hope to travel large interstellar distances, it will require technology superior to chemical-based rockets. (NASA/JPL-CALTECH)
The biggest problem with the idea of interstellar travel is scale. Distances to even the nearest stars are measured in light-years, with Proxima Centauri being our nearest neighbor at 4.24 light-years away, where one light-year is about 9 trillion kilometers: about 60,000 times the Earth-Sun distance. It covers the distance to the nearest star at the speed of the fastest space probes humanity has ever sent to exit the Solar System (Voyager 1 and 2 spacecraft). It will take approximately 80,000 years .
But all of this is based on existing technology that uses chemical-based rocket fuel for propulsion. The biggest disadvantage of rocket fuel is its inefficiency: according to Einstein's measurement, one kilogram of fuel can produce only milligrams worth of energy. E = mc² . Having to carry that fuel with you – and wanting to accelerate both your payload and the remaining fuel with that energy – is what's holding us back right now.
The position and orbit of Voyager 1 and the positions of the planets on February 14, 1990, the day the Pale Blue Dot and Family Portrait were taken. Note that it is only Voyager 1's position outside the plane of the Solar System that provides the unique images we receive, and that Voyager remains the farthest object ever launched by humanity, but has traveled thousands of times further by traveling ~4 light-years. (WIKIMEDIA COMMONS / JOE HAYTHORNTHWAITE AND TOM RUEN)
However, there are two independent possibilities that do not require us to imagine Warp Drive-like technologies based on new physics. Instead, we can either pursue ways to use a more efficient fuel to power our journey, which would tremendously increase our range and speeds, or we can explore technologies where the source of propulsion is independent of the payload to be accelerated.
- nuclear fission,
- nuclear fusion,
- and the matter-antimatter impulse.
While chemical-based fuels convert only 0.0001% of their mass into energy that can be used for propulsion, all of these ideas are much more efficient.
All rockets ever conceived require some form of fuel. Plasma engine, matter/antimatter engine, nuclear-powered or conventionally powered rockets all operate on the same principle of propulsion, but their efficiency can vary greatly. (NASA/MSFC)
Fission converts approximately 0.1% of the mass of fissile materials into energy; About one kilogram of fissile fuel produces about one gram worth of energy. E = mc² . Nuclear fusion does a superior job; For example, converting hydrogen into helium is 0.7% efficient: one kilogram of fuel yields 7 grams of usable energy. However, the most effective solution is matter-antimatter destruction.
If we could create and control 0.5 kilograms of antimatter, we could annihilate it at will with 0.5 kilograms of normal matter and create a 100% efficient reaction that produced a full kilogram of energy. We could probably extract thousands or even millions of times more energy from the same amount of fuel, which could take us to stars for centuries (by fission) or even decades (by fusion or antimatter).
An artist's rendition of a laser-guided sail shows how a large-area, lightweight spacecraft can be accelerated to very high speeds by continuously reflecting back high-power, highly tuned laser light. This may be the most likely way humanity will have in its arsenal to launch a macroscopic spacecraft across interstellar distances in the near future. (ADRIAN MANN / UCSB)
On the other hand, we could work to achieve interstellar travel in a completely different way: by placing a large power source in space that could accelerate a spacecraft. Recent advances in laser technology have led many to believe that in space a massive, sufficiently aligned array of lasers could be used to accelerate a spacecraft from low Earth orbit to tremendous speeds. A highly reflective laser sail, such as a solar sail designed specifically for lasers, could do the job.
If an in-phase laser array is built that is large enough, powerful enough, and potentially reaching gigawatt power levels, it can not only accelerate the target spacecraft, but can do so for long periods of time . Based on calculations a few years ago by Dr. Performed by Phil Lubin. It is possible to reach speeds of up to 20% of the speed of light. Although we have no plans to slow down such a spacecraft yet, it is possible to reach the nearest star in a single human lifetime.
The laser sail concept for a starship-type starship has the potential to accelerate a spacecraft to approximately 20% of the speed of light and reach another star within a human lifetime. With enough power, it's possible we could even send a crew-carrying spacecraft to cross interstellar distances. (BREAKING STAR IMAGE)
Likewise, the search for extraterrestrial life is no longer limited to waiting for an alien visit or searching the Universe via radio signals for intelligent aliens, although the latter is certainly an active scientific field pioneered by SETI. Although no signal was found, this remains a striking example of high-risk, high-reward science. If a positive determination is made, it will be a civilization-changing event.
However, as exoplanet astronomy continues to advance, two already proven techniques may bring us our first signatures of life on other worlds: transit spectroscopy and direct imaging. These both involve using light from a planet itself, with transit spectroscopy making use of light filtered through a planet's atmosphere and direct imaging making use of sunlight reflected directly from the planet itself.
When a planet passes in front of its parent star, not only is some of the light blocked, but if an atmosphere is present, it filters through it, creating absorption or emission lines that a sufficiently sophisticated observatory can detect. If there are organic molecules or a large amount of molecular oxygen, we can also find it. at some point in the future. It is important that we consider not only the signatures of life we know, but also the signatures of possible life that we cannot find here on Earth. (ESA / DAVID SONG)
Transit spectroscopy relies on our observatory having a coincidental alignment with both the target exoplanet and its host star, but these alignments do occur. While a small portion of the starlight will be blocked by the transiting planet, an even smaller portion of the starlight will pass through the planet's atmosphere, similar to sunlight transmitted through Earth's atmosphere and illuminating the Moon (in red). total lunar eclipse.
This allows us to work out what elements and molecules are present in the target planet's atmosphere if our measurements are good enough. If we could discover biosignatures or even techno-signatures, which could be something like an oxygen-nitrogen atmosphere, complex biomolecules, or even a chlorofluorocarbon (CFC) molecule, we would have a strong hint of a living world waiting to be confirmed immediately, tantalizingly.
Left, an image of Earth from the DSCOVR-EPIC camera. That's right, the same image has been reduced to a 3 x 3 pixel resolution, similar to what researchers will see in future exoplanet observations. (NOAA/NASA/STEPHEN KANE)
Direct imaging can provide exactly this type of verification. Although our first image of an Earth-sized exoplanet probably won't be very visually impressive, it will contain a ton of information that can be used to reveal indicators of life. Even if the planet itself is just one pixel in a detector, we can not only split its light into individual wavelengths but also look for time-varying signatures that can reveal:
and more. If there are signatures that emit light at night, we can probably detect them, just like planet Earth has our light illuminating the world at night. If there is a civilization on an Earth-like planet nearby, next-generation telescopes could find them.
Earth emits electromagnetic signals at night, but creating such an image from light years away would require a telescope of incredible resolution. Humans have become an intelligent, technologically advanced species here on Earth, but even if this signal is dispersed, it can still be detected with next-generation direct imaging. (NASA'S EARTH SURVEILLANCE/NOAA/DOD)
All this together points to a picture where a spacecraft, or even a crewed journey to the stars, is technologically within our reach, and the discovery of our first potentially habitable world beyond the solar system could occur within a decade or so. 2. What was once only the realm of science fiction is rapidly becoming possible, thanks to both technical and scientific advances and the thousands of scientists and engineers working to implement these new technologies in practical ways.
On February 5 at 7 PM ET (4 PM PT), Dr. Bryan Gaensler will be giving a public lecture at the Environmental Institute on exactly this subject. Titled Warp Drive and Aliens: The Scientific Perspective , it can be watched from anywhere in the world, and I'll be following along with a live blog in real time below.
How close is humanity to realizing this dream that spans countless generations? The answer is closer than you think, so stay tuned here and follow below to find out what's just beyond the known limit (updated every 3-5 minutes). It could be the revolution we've all been hoping for!
The live blog starts at 3:50 PM Pacific Time, with all timestamps shown below starting from that starting point.
An illustration of the warp field in Star Trek, which shortens the space in front of it while lengthening the space behind it. Spore Drive, the idea of traveling through an extra spatial dimension in both Star Trek and our reality, can get us from point A to point B even faster. (TREKKY0623 ENGLISH WIKIPEDIA)
15:50 : OK, warp drive fans, here we go! The first thing you might wonder is whether warp drive itself is actually feasible. And the answer, believe it or not, is maybe, unless we find a source of energy that goes far beyond anything we have so far, including antimatter.
The reason is simple: to achieve warp drive, you need to bend the space in front of you into contraction, and this can only come at the expense of expanding the space behind you. This requires a huge amount of energy, all localized in a single spot, and you need to do this while maintaining space where your spaceship won't bend too much, or you'll destroy it with awesome gravitational tidal forces.
The Alcubierre solution for General Relativity provides warp drive-like motion. This solution requires negative gravitational mass, which would be exactly what antimatter could provide. (WIKIMEDIA COMMON USER ALLENMCC)
3:54 AM : But if you can do that, and it's something allowed in General Relativity, it requires not only matter and energy as we know it, but also some form of negative energy: either matter with negative mass, or some form of anti-energy itself. If we can use this it means we can travel through contracting space (slower than light), but we can do something like contract a journey of 40 light years to 6 light moons.
Even if we were to pass through this currently narrowed space at half the speed of light, we could get there in 1 year instead of 40. This is pretty impressive!
The warp propulsion system on Star Trek starships is what made star-to-star travel possible. If we had this technology, we could easily close the distance to the stars, but this remains in the realm of science fiction for now. Star Trek Discovery's Spore Drive opens up a new possible mechanism for faster-than-light travel that could be superior even to Warp Drive. (ALISTAIR MCMILLAN / CC-BY-2.0)Although more than 4,000 confirmed exoplanets are known and more than half of them have been discovered by Kepler, finding a Mercury-like world around a star like our Sun is far beyond the capabilities of our current planet-finding technology. As seen by Kepler, Mercury will appear to be 1/285th the size of the Sun, making it even more massive than the 1/194th size we see from Earth's perspective. (NASA/AMES RESEARCH CENTER/WORLDS LIKE THE MISSING EARTH BY JESSIE DOTSON AND WENDY STENZEL; E. SIEGEL)
16:55 : We found water worlds and lava worlds, but they're… well, probably not the best candidates for interesting alien life. Neither are hot Jupiters (or any type of Jupiter) or any gas planet with a large hydrogen/helium envelope.
Just like in our own Solar System, most planets are not expected to have life on them.
16:56 : This is a completely trivial point, but for an astronomer, it bothers a lot of people.
The smallest stars in the universe are red dwarfs. Always midgets, never midgets. The plural of dwarf (for stars) is dwarf; The plural of dwarf (for a fantasy race of short, fat, bearded, axe-wielding characters) is dwarves.
3:57 AM : But that doesn't mean that plot devices or treknobabble by Star Trek's writers are things that include:
or anything we can immediately refer to has any relevance. Science fiction provides us with possible outcomes, but very rarely gets the path to that technological solution right. We know enough about physics today to be confident that Star Trek's solution to this problem is not possible. But it's still part of what makes science so great: it can take a fictional idea and turn it into reality. Or if we're really lucky, transcend our sci-fi dreams!
Representation of an alien invasion. This is not a real extraterrestrial. (FLICKR USER PLAITS)
16:00 : On the other hand, based on what we know about the ingredients of life in the Universe, how chemistry works, and exoplanets around other stars that have the right conditions for life, aliens are probably everywhere. In our galaxy alone, we have literally billions and billions of potentially habitable planets with conditions similar to early Earth. In many models, early Venus and Mars looked similar to early Earth.
Are we supposed to believe that Earth, where life emerged in the first ~3% of our planet's history, is somehow unique in this respect? While ending something human-like is a tough proposition, ending up with no life at all among billions and billions of other examples with similar starting conditions seems much more so. Improbable, at least from a scientific perspective.
16:01 : Hooray for another timely start, Greg Dick, executive director of the Perimeter Institute, gets us started right on time with his introduction!
16:02 : Oh, before I forget, Bryan is Australian, so prepare for an accent, but it won't be the strongest Australian accent you've heard by a long shot!
16:03 : And that's a pretty quick introduction! Here we go; wonders what scientific perspective means according to an astronomer/astrophysicist. not I!
16:05 : Spoiler: We don't have warp drive yet and we haven't found the aliens yet. I love hearing this up front, but I also love your optimism that science can pretty much make all our dreams come true that violate the laws of physics. I think, at best, that's what we all dream of for science.
16:07 : Bryan definitely talks about an important aspect of being exposed at a young age not just to the answers to what we know, but also to what the limits of science are, what's unknown. Discovering at age five that adults, parents, teachers, and even experts (libraries and encyclopedias) don't know the answers to everything.
And there are people who find the answers to these questions, and they are just ordinary people, and he might be one of them.
Please note that this applies to everyone! You can do it too, and you don't have to figure it out at age 5 to do it.
From inflation to the hot Big Bang, to the birth and death of stars, galaxies, and black holes, to our ultimate dark energy destiny, we know that entropy never decreases over time. But we still don't understand why time itself flows forward. However, we are pretty sure that entropy is not the answer. (WITH IMAGES FROM E. SIEGEL, ESA/PLANCK, AND THE DOE/NASA/NSF INTERAGENCY TASK FORCE ON CMB RESEARCH)
16:10 : And this is a lot of fun: the fact that questions we didn't even know we needed to ask can be uncovered by finding answers to previous scientific questions. We didn't know in the 1920s that the Universe was expanding, but its discovery led to the idea of the Big Bang. In the 1960s, we didn't know the Big Bang was true, but its confirmation raised questions about what came before it and what the ultimate fate of our Universe would be.
And now, as you can see, we are now talking about the mysteries of cosmic inflation and dark energy, which is where these boundaries lie. And in any field, that's how it works: discovering an answer only reveals a deeper frontier we haven't discovered yet.
16:11 : I love how Bryan defines the difference between science and science fiction. Science is about discovering and following rules; science fiction is about breaking these rules. I haven't thought clearly about these terms and I accept that this is generally how it works. I don't know if that's why I dislike various forms of science fiction, but it's a new perspective for me.
16:13 : We have constantly evolving technology, and science fiction asks how developing technology will change our lives. It brings up the Westworld example, which I love, but I really think it misses a golden opportunity to reference Black Mirror, which highlights and celebrates the dystopian aspects of our society in a new way with each episode.
An animation showing the path of the interstellar interloper now known as ʻOumuamua. The combination of speed, angle, orbit, and physical properties lead to the conclusion that it came from beyond our Solar System. (NASA/JPL—CALTECH)
16:15 : Okay, some science! Here we move on to the interstellar interloper 'Oumuamua, one of the things we see that isn't particularly anticipated even by science fiction. Still, Bryan is right to point out that Star Trek IV: The Voyage Home features a cigar-shaped alien asteroid in our own solar system.
Of course, it doesn't tell us to save the whales, and it's not a space probe, but it's remarkable that science fiction had this idea before astronomers or any scientists knew it was coming.
The first published image from the Event Horizon Telescope achieved resolutions of 22.5 microarseconds, allowing the array to resolve the event horizon of the black hole at the center of M87. To achieve the same sharpness, a single-dish telescope would need to be 12,000 km in diameter. Note the different appearances between the April 5/6 images and the April 10/11 images, which show that the features around the black hole change over time. This helps demonstrate the importance of synchronizing different observations rather than simply time averaging. (EVENT UHUK TELESCOP COOPERATION)
16:18 : This is a little less fair. While we're talking about old movies that talk about black holes, it's not really fair to talk about how we know what black holes would look like in science fiction, because black holes had been theorized astrophysically for decades until the 60s, 50s, or even 1916 and even earlier in the context of General Relativity (of the 18th century). breaks) in Newtonian gravity.
Fascinating, sure, but visualizations based on a mix of science and artistic license have been around for as long as we've known enough about science to realistically imagine what could happen. Also, as a side note, it is highly unlikely that an interstellar black hole is what we see when we examine our realistic black holes with superior accuracy; There's a lot of artistic license and some non-physical assumptions made for Insterstellar.
Artist's drawing of two merging neutron stars. Binary neutron star systems also inspire and merge, but the closest orbiting pair we find in our own galaxy will not merge until about 100 million years later. LIGO will probably find others before then. (NSF / LIGO / SONOMA STATE UNIVERSITY / A. SIMONNET)
16:22 : Well, I don't think it's right to say well, we simulated and visualized this astrophysical event and then observed it, and this is an example of science leaving science fiction behind.
Yes, it's true that the entire Universe is shaking… but not every scientific event, including planet Earth shaking less than an atom's width, makes for particularly good science fiction. He's said before, remember, that science fiction is about exploring the human condition. It's hard to see how a small, subtle effect like this could make for a good sci-fi story.
The hyperdrive from Star Wars appears to depict ultra-relativistic motion through space, extremely close to the speed of light. If you are made of matter, according to the laws of relativity, you can neither reach nor exceed the speed of light. But if you have a large enough quantity of an efficient enough fuel, you can get close to it. Dark matter may fit exactly the conditions we need to make this sci-fi dream a reality. (JEDIMENTAT44 / FLICKR)
16:25 : Okay, this bothers me. Do you know why things like rockets and space shuttles are the shapes they do? That long, narrow cone shape you're familiar with? Due to atmospheric drift.
If you're going to build and fly your ship in space , just in space, you don't need to take aerodynamic considerations into account! You'd be much, much smarter to build a structure with a good volume-to-surface-area ratio: a sphere. The Death Star, not the Millennium Falcon or X-Wing, will be much more practical for the structures we will build in space!
The NEXIS Ion Thruster at Jet Propulsion Laboratories is a prototype for a long-duration thruster capable of moving large-mass objects over very long time scales. (NASA/JPL)
16:28 : Ion drives are real and very cool. But if you want to power a trip long distances in a reasonable amount of time, ion drives won't get you very far at all. As Bryan said, they can take you up to ~6 billion kilometers in 11 years, and they can do it very efficiently. But if you factor in that distance as an average acceleration over that time, you get something truly terrifying: 100 nanometers per second².
You… won't go too far too fast. ~100,000 years to nearest star, the same as with conventional fuel. I will pass, thank you.
Normally, structures like IKAROS, shown here, are viewed as potential sails in space. However, if a large-area object were placed between the Earth and the Sun, it could reduce the total radiation received at the top of our atmosphere and potentially combat global warming. (WIKIMEDIA COMMONS USER ANDRZEJ MIRECKI)
4.30 PM : Hey, solar sails! Yes, if you speed up with a solar sail, you can slow down with a solar sail! The fuel is simply the radiation provided by a star, so as long as you visit a star similar to the Sun, you can slow down the same way you speed up.
Unfortunately, this technology is inferior to Ion drives not only in terms of distance reached, but also in terms of acceleration and control over your spacecraft. A nice idea, but one that is at best in its infancy, despite being proposed by Johannes Kepler more than 400 years ago!
16:32 : 75 years?! This… this is a very light load and it will take a very, very large and efficient load over a distance of 1.8 kilometers. Can we do this for ~4 light years or 20 trillion kilometers? That's... that's all I have to say good luck.
EmDrive device originally displayed by Roger Shawyer's company, SPR Limited. (SPR LIMITED)
16:33 : Hey, stay out of date, Bryan! The Em Driver was completely debunked a few years ago . Nice idea, but it's over.
Quantum teleportation is an effect (mistakenly) touted as faster-than-light travel. In reality, no information is exchanged faster than light. However, the phenomenon is real and compatible with the predictions of all applicable interpretations of quantum mechanics. (AMERICAN PHYSICAL SOCIETY)
16:36 : Note that quantum teleportation does not involve teleporting a particle, it involves teleporting the quantum state of a particle. Bryan gets this right, but it doesn't solve the problem of teleporting an inanimate object, a person.
16:38 : Yes, you need a lot of information to code a person. Remember that there are approximately ~10²⁸ atoms in the human body, which means something like 10²⁹ or 10³⁰ bits of quantum information. As Bryan said, I don't think we'll be teleporting anytime soon.
The travel time for a spacecraft to reach a target if it accelerates at a constant rate of Earth's surface gravity. Remember that given enough time you can go anywhere. (P. FRAUDORF ON WIKIPEDIA)
16:40 : Hey, don't get mad at time dilation! Time dilation is what can take us to the stars in a human lifetime. If you wanted to go further than ~100 light years, it would always take more than ~100 years (a human lifetime at the extreme) to get there from the frame of reference of a person staying on Earth.
But if you keep accelerating at 1 G , or 9.8 m/s², you will get where you want to go on a much shorter time scale than your frame of reference because you are traveling close to the speed of light. Time dilation rules!
An artist's rendering of a starship using the Alcubierre drive to travel faster than the speed of light. By combining warp technology with the mycelium drive and the ship's shields, Stamets and Tilly devise a plan to get Discovery home while keeping the mycelium network intact. (NASA)
16:42 : OK, really? From long, long-term technologies like ion drives and solar sails to direct warp drive with nothing in between? In terms of not using fuel , Bryan is right. But in terms of not using energy… well, (reminder) that the curvature of space-time is based on matter-energy, good luck transforming your space-time without wasting energy!
The DEEP laser sail concept relies on a large laser array striking and accelerating a relatively large-area, low-mass spacecraft. This has the potential to accelerate non-living objects to speeds approaching the speed of light, enabling interstellar travel within a single human lifetime. The work done by a laser by applying a force as an object moves a certain distance is an example of the transfer of energy from one form to another. (2016 UCSB EXPERIMENTAL COSMOLOGY GROUP)
16:43 : Wait, he'll finish How are you today part of his speech now, he talks about the previously mentioned Breakthrough Starshot (and laser sail technology and a starch ship spaceship) and covers aliens… what, 10-15 minutes? We'll see!
16:45 : No; We haven't gotten to the aliens part yet; we're still talking about femtosatellites that are quite large and weigh a few grams, which is still too much for Breakthrough Starshot.
Tiny particles known as micrometeoroids will hit anything they encounter in space, potentially causing a very significant amount of damage as a result, especially when impacts accumulate over time and occur at higher speeds. (NASA; SAFE WORLD FOUNDATION)
16:48 : Yes! This is something I'm excited to hear, because it's something I bring up that very few people talk about: when you travel at relativistic speeds through space, you're going to hit things in the interstellar medium! And this thing will wear down your spacecraft really quickly, and there's nothing to protect your starship (even if it has a microchip) from hitting that dust.
Remember that a small piece of nerf-like foam at high speeds was all it took to cause the Space Shuttle Columbia disaster. Remember that all our spaceships were hit by micrometeoroids. And remember, 20% of the speed of light is about 100 times faster than our fastest spacecraft travel, which means they have 10,000 times more kinetic energy from dust particle collisions. This is a harder problem to tackle than anyone has found an appropriate way to take into account.
16:50 : Okay, about the aliens part and I have to disagree with what Bryan said. We don't want to go to planets around other stars. to look for life; We want to find planets where life exists (or is likely) and then go there.
There are ~400 billion stars in our galaxy. Do you want to go on a wild goose chase, or do you want to know where you're going before embarking on a decades-long journey across the great void?
(Choose the second one.)
When Hubble pointed at the Kepler-1625 system, it found that the first transit of the parent planet began an hour earlier than expected, followed by a second, smaller transit. These observations were certainly consistent with what you would expect for an exomoon present in the system. (NASA'S GODDARD SPACE FLIGHT CENTER/SVS/KATRINA JACKSON)
16:53 : Using the transit method, we can learn the characteristics of planets orbiting stars, and they come in a huge variety. It didn't Let's assume the rest of the universe was just like our little corner. We found the easiest planets to find, and that means the largest planets relative to their stars in close orbits. This, unsurprisingly, skewed the population of the planets we found.
Although more than 4,000 confirmed exoplanets are known and more than half of them have been discovered by Kepler, finding a Mercury-like world around a star like our Sun is far beyond the capabilities of our current planet-finding technology. As seen by Kepler, Mercury will appear to be 1/285th the size of the Sun, making it even more massive than the 1/194th size we see from Earth's perspective. (NASA/AMES RESEARCH CENTER/WORLDS LIKE THE MISSING EARTH BY JESSIE DOTSON AND WENDY STENZEL; E. SIEGEL)
16:55 : We found water worlds and lava worlds, but they're… well, probably not the best candidates for interesting alien life. Neither are hot Jupiters (or any type of Jupiter) or any gas planet with a large hydrogen/helium envelope.
Just like in our own Solar System, most planets are not expected to have life on them.
16:56 : This is a completely trivial point, but for an astronomer, it bothers a lot of people.
The smallest stars in the universe are red dwarfs. Always midgets, never midgets. The plural of dwarf (for stars) is dwarf; The plural of dwarf (for a fantasy race of short, fat, bearded, axe-wielding characters) is dwarves.
If TOI 700d were a cloudless, dry land planet with an atmosphere similar to modern Earth, it would have a potential habitable ring with Earth-like temperatures and atmospheric pressures near the boundary between eternal day/night sides, where winds are always present. It flows from the night side to the day side. (ENGELMANN-SUISSA ET AL./NASA'S GODDARD SPACE FLIGHT CENTER)
16:59 : This is also an important point: What happens in a world around a red dwarf star is not about the radiation from the star and the day/night temperatures and the boundary between them, but about how the atmosphere circulates and what it is made of. .
We also have to be very careful in distinguishing between biosignatures, which will be a slam dunk signal that tells us, wow, there's a living planet right there, and a biosignature is what Bryan was talking about, which is a biosignature. In fact, it's sure to give you false positives over and over again before you get it right.
This diagram shows the new 5-mirror optical system of ESO's Extremely Large Telescope (ELT). Before reaching the science instruments, light is first reflected from the telescope's giant concave 39-meter segmented primary mirror (M1), then reflected from two 4-meter class mirrors, one convex (M2) and one concave (M3). The last two mirrors (M4 and M5) form a built-in adaptive optics system to allow extremely sharp images to be created in the final focal plane. This telescope will have more light-gathering power than any telescope in history and better angular resolution of up to 0.005 inches. (ESO)
17:01 : It's actually true: ELT will be humanity's best chance in the 2020s to directly image an Earth-like (or potentially inhabited) planet of any kind. This could lead us to a revolution where bio-cues and bio-signatures abound. Currently, planet finders like TESS are giving us the best candidate planets for direct imaging, and although we should be lucky, this is the high-reward science many of us dream of!
In this artist's rendition, NASA's Clipper spacecraft makes one of its many flybys of Europa, the most likely candidate for life in the Jovian system to date. Europa, with all its components and conditions as we know them on this earth, may be the most life-friendly world beyond Earth currently known to humanity. However, to know if there is life in Europa's subsurface ocean, we will need to probe beneath its extremely thick crust, which is approximately 15+ kilometers thick. (NASA/JPL-CALTECH)
17:04 : Of course, this is the third possibility for finding life that I haven't discussed: it could be right here in our Solar System! Do we have life in a subsurface ocean on Europa or Enceladus? Is there potentially seasonally active/inactive life underground on Mars? Is there anything interesting on outside worlds like Triton or Pluto?
We have tasks to look at, and hopefully in the 2020s we will start to get answers that will teach us whether fantasy interpretations of signals like seasonal methane or organic molecules really work. They may be biotic in nature and we won't know until we do the appropriate testing!
A small part of the Karl Jansky Very Large Array, one of the largest and most powerful radio telescope arrays in the world. The radio capabilities of this array, in terms of resolution and sensitivity, place it in the top 2 or 3 arrays in the entire world. (JOHN FOWLER)
17:06 : This is a fun fact: you should not use a walkie-talkie around radio telescopes; intervention is disgusting! Remember when people didn't know what fast radio bursts were for much longer than we realized because the microwave oven in the workroom of a giant radio telescope was causing interference? This is a true story; Do not use radios near radio telescopes!
17:10 : The present and the near future are incredibly exciting and you don't need warp drive or real aliens to make it happen. But it would be pretty cool to achieve interstellar travel or find actual signatures (not just hints + wishful thinking) of alien life.
That's why we do science and develop technology; These are our sci-fi dreams and we are making them come true!
17:12 : Okay, the talk is over and we move on to the Q&A. Hey, and the first question is, how do we go about extracting all that useful information from that light of an exoplanet passing? And two answers:
- transition spectroscopy and
- direct viewing.
Bryan only gives the first answer, but both are important!
17:14 : No to aliens in Roswell, New Mexico. Good answer, Bryan. Why did you come all this way to examine a cow?
Alright everyone, that's all the time I have for today's talk; I hope you enjoyed the live blog and Bryan's talk! We may not have found aliens yet, and we may still be a long way from reaching another star, but our technology has already brought us a pretty impressive path forward, and we're headed for something even more spectacular as the 2020s begin to unfold. Stay curious and please join me in looking forward to all the wonderful discoveries this decade is sure to hold!
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