Reaching the known Universe and Project Hail Mary

 

The movie Project Hail Mary touches on a topic about which I recently wrote. That being the ability to reach any point in the Universe within a human lifetime using relativist travel. Time Dilation Visualized is an excellent video that helps visualize both the movie itself and the general discussion as well. Have fun watching and reading about this fascinating exploration.

Also see:

• Earth's Looming Expiration Date
• Habitable Pit-Stop with Mars
• Humanity's Last Homes in our Solar System
• Interstellar Ark to Race to the Stars and Against Time
• Colonizing the Universe at Sub-Light Speed
• Reaching the known Universe and Project Hail Mary

Colonizing the Universe at Sub-Light Speed

The Ultimate Relativistic Sacrifice

Assuming Faster-Than-Light (FTL) travel is physically impossible and cryogenic hibernation is unavailable; humanity's expansion into the cosmos may rely on the extreme physics of time dilation from Special Relativity aboard some sort of colony ark. While time dilation will allow the crew to complete a voyage within their lifetime, the journey is an irreversible commitment that gambles the future of a civilization on a target millions of light-years away.

---

The Andromeda Challenge and the Irreversible Loss

The Andromeda Galaxy (M31) is our nearest major intergalactic target at approximately 2.5 million light-years distant. For the crew to complete this voyage in a human lifetime (e.g., 40 years of proper time), the ship must maintain a sustained average velocity of roughly 99.99999999995 c.

• The Sacrifice: The travelers are not simply leaving home. They are permanently severing their connection to the Milky Way. When they arrive, 2.5 million years of cosmic, stellar, and biological evolution will have occurred in their home galaxy. Their families, their culture, and every trace of the civilization that launched them will be reduced to ancient memories.
• A Temporal Gap: The voyagers exist in a tiny bubble of compressed time from which they will step into a universe that is unrecognizable to the one they left. They will have to pay millions of years of separation for their mere decades of travel.

---

The Existential Gamble

The greatest human impact lies in the uncertainty of the destination. The colony ark, having made the ultimate sacrifice, arrives 2.5 million years later. The pioneers will dependent on finding a habitable world.

• Arrival on a Dead World: There is no guarantee of success. Target systems that looked promising via telescopes 2.5 million years ago may have undergone catastrophic changes. Target stars may have died, planetary orbits destabilized or life-bearing worlds may have been sterilized by a nearby supernova. The crew may be forced to settle a barely viable moon or asteroid, dedicating their compressed lives to the construction of a fragile habitat.
• The Psychological Toll: Imagine emerging from a forty-year journey to find that the sacrifice of millions of years was in vain. Settlement options leave them desperate and even face slow extinction. The mental fortitude required for the crew to proceed with establishing a colony under such bleak conditions will be very a demanding for human endeavor.

---

Cosmic Expansion and the Event Horizon

The navigational challenge of intergalactic travel is a matter of pure survival, where failure means being permanently stranded in the dark void between galaxies.

1. The Super-Deep Space Trap

The massive target distance requires the ark to compensate for both the target galaxy’s movement and the expansion of the universe (Hubble flow) over millions of years.

• Aiming for the Past: The crew must not aim for where Andromeda is now, but where cosmological models predict it will be millions of years in the future.
• Gravitational Anchor: The ship must execute an instantaneous deceleration precisely within the gravitational well of the destination galaxy. If the deceleration occurs even slightly too far out, the surrounding spacetime expansion could accelerate the ship away from the galaxy before its local gravity can pull it in, stranding the crew in the empty, super-deep intergalactic void.

2. Reaching the Cosmological Edge

The concept of colonizing galaxies near the cosmological event horizon (currently 16 billion light-years away) highlights the final limit. Galaxies beyond this horizon are already receding faster than light due to accelerating cosmic expansion and are literally unreachable today, even at 0.999… c.

• The Temporal Trap: To reach a galaxy near the horizon, the launch must occur almost instantaneously on the cosmic scale. If humanity delays too long, cosmic expansion will push that galaxy irrevocably beyond our reach, forever confining future generations to our local galactic neighborhood.

---

The Enduring Drive: A Galactic Legacy

Despite the risks and the terrifying finality of the journey, the impetus for expansion remains. We have an innate and evolutionary imperative to survive and propagate.

• Successive Generations: If a colony succeeds in Andromeda, its primary goal is not to thrive, but to replicate the mission. The next generation of settlers will build their own relativistic arks, pushing further into the Laniakea Supercluster, driven by the knowledge that their future depends on finding and securing more footholds in the cosmos.
• A Galactic Civilization: Each new colony, whether on an Earth-like world or in a sealed dome on a cold moon, becomes a new seed of humanity, creating a truly scattered, time-dilated galactic civilization whose survival is secured not by technology alone, but by the extraordinary sacrifice and unyielding courage of the original voyagers.

The Unavoidable Horizon and the Next Step

Such a relativistic colony ark would be more than just a ship. It will be a declaration of humanity's unyielding commitment to existence that must be secured regardless to possible costs. This colonization model, constrained by the immutable laws of physics (the speed of light and the accelerating expansion of the universe) forces us to recognize a sobering truth. Our window for becoming a truly galactic civilization is finite and closing.

The greatest challenge is not merely building the next ark, but cultivating the societal will to invest in such a millennia-spanning gamble. Before the first interstellar journey can even begin, we must achieve a few critical milestones:

• Establish a Self-Sufficient Solar System: We must first master the art of survival away from Earth. Settling the Outer Solar System, as previously discussed, is the required engineering training ground, guaranteeing that the seed of humanity does not perish with the inevitable death of the Sun.
• Achieve Kardashev Type II Capability: The energy requirements for a sustained 0.999… c voyage is so vast that they demand harnessing the power output of an entire star. This requires a civilization with an unprecedented scale of infrastructure and coordination.
• Embrace the Temporal Sacrifice: The success of the journey rests on the psychological endurance of the travelers and the emotional maturity of the home world to accept the irreversible loss.

The final question for our species is no longer "Can we reach the stars?" but "Are we worthy of them?" Our willingness to make the ultimate sacrifice and to gamble millions of years of our history for the chance of a single new beginning will define whether humanity remains a fragile, single-star species or evolves into an enduring, time-scattered intergalactic legacy. The time to prepare for this final, defining endeavor begins now, before the accelerating expansion of the cosmos locks our future out of reach forever.

---

What Do We Do Now?

The path forward is clear. We need to Master our local region in order to plan for the galactic expanse. We should relentlessly pursue advances in fusion power, closed-loop life support and extreme deep-space navigation. We can act knowing that every technological victory at the solar scale moves us one step closer to making the ultimate and irreversible jump to the stars.

Also see:

• Earth's Looming Expiration Date
• Habitable Pit-Stop with Mars
• Humanity's Last Homes in our Solar System
• Interstellar Ark to Race to the Stars and Against Time
• Colonizing the Universe at Sub-Light Speed
• Reaching the known Universe and Project Hail Mary

Moon, Venus and Regulus having a party in the morning sky

What I saw on the morning of Sept 19 thru my window. I went outside to snap this shoot. My trusty Pixel was able to reasonably capture the sight with very little effort.

Instagram: https://www.instagram.com/p/DOyIojmjtsn/?hl=en

Recent news tour of our Solar System from Mercury to FarFarOut

Some recent news tour of our Solar System:

• Mercury: Study Reveals MESSENGER Watched a Meteoroid Strike Mercury - Combing through data from NASA's MErcury Surface, Space ENvironment, GEochemistry and Ranging (MESSENGER) mission to Mercury reveals it likely watched a meteor slamming into the planet.
• Venus: Life on Venus? The Picture Gets Cloudier, doubtful - After a sensational announcement about the possibility of life on Venus, new doubts arise.
• Earth: Astronomers Think They've Found Another Trojan Asteroid Lurking in Earth's Orbit - A recently discovered object sharing Earth's orbital path around the Sun could actually be a trojan (shares a planet's orbit) asteroid, astronomers have found.
• Mars: Mars Mission From the U.A.E. Begins Orbit of Red Planet - U.A.E.'s probe arrives to Mars soon.
• Asteroid Belt: The Asteroid Belt: Wreckage of a Destroyed Planet or Something Else? - Samples of asteroids that have fallen to Earth reveals that the Asteroid Belt likely wasn't formed from planet that was smashed a part.
• Ceres and other Dwarf Planets:Top 10 Giant Facts About the Dwarf Planets - "Despite being the smallest of the five dwarf planets, Ceres was the first one discovered."
• Jupiter: Jupiter Is Bigger Than Some Stars, So Why Didn't We Get a Second Sun? - Jupiter and Sun have a lot in common, so how did Jupiter end up not being a planet?
• Saturn: Saturn's moon Titan: Largest sea is 1,000-feet deep - "Far below the gaseous atmospheric shroud on Saturn's largest moon, Titan, lies Kraken Mare, a sea of liquid methane. Cornell University astronomers have estimated that sea to be at least 1,000-feet deep near its center -- enough room for a potential robotic submarine to explore."
• Uranus: 35 Years Ago: Voyager 2 Explores Uranus - 35 years ago, Uranus was examined by Voyager's 11 instruments.
• Neptune: Next-generation planetary missions could hunt for gravitational waves, say astronomers - "Spacecraft heading to Uranus and Neptune in the next decade could be used to investigate gravitational waves as they venture into the outer Solar System."
• Pluto: Pluto's atmosphere gets its blue haze from icy organic compounds, study suggests - "The haze shrouding Pluto might be made up of ice crystals possessing cyanide hearts, a new study finds."
• Quaoar: How 50000 Quaoar changed the way we look at our solar system - "The ball-shaped planetoid, approximately half the size of Pluto, is the largest object found in the solar system since Clyde Tombaugh discovered Pluto in 1930."
• "FarFarOut": Astronomers Just Confirmed The Most Distant Known Object in The Solar System - "The most distant known object in the Solar System is now confirmed. FarFarOut, a large chunk of rock found in 2018 at a whopping distance of around 132 astronomical units from the Sun, has been studied and characterised, and we now know a lot more about it, and its orbit."

Select the image for attribution and licencing info.

Video: What Would Trees Look Like On Other Planets?

Related articles

• Monkeydactyl: Pterosaur to Human?
• Video: What Would Trees Look Like On Other Planets?
• Predictions of Evolution of Alien Life
• Communication with Alien Civilizations
• Odds of Humanoids Evolving again
• Part 5: Blue Plants
• Part 4: Silicon Life
• Part 3: Arsenic Life
• Part 2: Exotic Amino Acids
• Part 1: Mirror Life

Super blood wolf moon eclipse 2019, as best as I can get by handholding my phone

Tonight's Lunar Eclipse.  I didn't even know about it until I saw the Earth's shadow upon the moon while casually looking out a living room window.  As soon as I saw, I started watching in the backyard; and experimenting with my phone camera to capture the moments.

Via Instagram http://bit.ly/2DoOPMe

 Via Instagram http://bit.ly/2TYMaym

 Via Instagram http://bit.ly/2Do5mAc

Almost to the total Lunar Eclipse. This is about as good of a shot I can get handholding my phone. Peak of the total eclipse is in about 15min; via Instagram http://bit.ly/2MssKQ1

This photo was taken near the peak.  It took a fair amount of Instagram filter use to bring this photo to the point of being marginally recognizable; via Instagram http://bit.ly/2sEQRSl

Meyer–Womble Observatory on Mount Evans.

via Instagram http://ift.tt/2sP7XLV

Planetizing Pluto

It seems that main reason why we care so much about what is and is not a planet is due to the Astrological origins of Astronomy. The word "planet" is derived from a Greek word for "wanderer", as in a star that wanders around the sky. Earth wasn't considered a planet by this ancient definition.

Today, the term planet isn't special, and things we call planets shouldn't be special either. The current definition of the word "planet" by IAU doesn't make any sense since it pretty much invalidates all the planets of "planet" status with the 2006 addition "A planet is a celestial body that has cleared the neighborhood around its orbit."  For example, Pluto is tied to Neptune's orbit. So, technically, Neptune's orbit hasn't been cleared of other objects (the biggest being Pluto's system), so Neptune isn't a planet. IAU definition presents us with a mess. We need to stop treating the word "planet" like it's some special term. "Planet" is just a word and it should be used to describe a well defined class of objects that aren't determined by ancient superstitions.

Always emotions

One of the common statements by those who argue against the application of the term "planet" to Pluto is that those who want to categorize Pluto as a planet want this for "mostly for emotional reasons".  However, the very reason Pluto was "demoted" was for mostly emotional reasons. Here's how:

The definition of "planet" adopted in 2006 by the IAU actually invalidates all other planets from the class as well, particularly the big ones.  Also, the IAU still named Pluto a type of planet called "Dwarf Planet" while in the same breath saying that it is no longer a planet.  These oversights were due to the 2006 definition not being vetted by scientists in the field of study (which is supposedly a violation of IAU policy).  Why was this definition pushed so hard that it by-passed normal procedures?  Someone was trying to game the system.

In my opinion, the whole thing is a mess because Michael Brown (self-described "Pluto Killer") and others of similar opinions wanted to have some fun trolling the IAU.  He has reportedly stated many times how much fun he had with the reclassification of Pluto.  If anything is emotional, it was the whole effort to "demote" Pluto for a bit of fun.

A Different Perspective

What would our thoughts be if we evolved on a rocky orb that revolved around some Gas Giant?  If we looked out at this alternative solar system, we'd see all these other rocky orbs; some orbiting one of several Gas Giants and some orbiting the primary star.  Would all the Gas Giants be known by the same name that we'd called our own rocky orb?  No. We'd call the Gas Giants something else, and all the rocky orbs would be called by the same classification as our own world, regardless to them orbiting a Gas Giant or orbiting the star.  There wouldn't even be a concept of "moon".

The main reason we have trouble with this whole "moon" and "planet" classification is because of our own Earth-centric view of our solar system. The reason some people try to protect the word "planet" is rooted in ancient superstitions that people don't realize they are still perpetuating.  We need to break free of this ancient beliefs and just use science to categorize things in a neutral and fact based manner.  We need a real definition for the word "planet" which isn't implemented for unvetted and emotional reasons, but rather being based on hard facts.  We need a definition developed by a body of Planetary Scientists who base their conclusions on geophysical traits.

For more information about Pluto and New Horizons, please read Chasing New Horizons.

Maybe we are the first

I've said several times that it is possible that the human species is the first species in the Milky Way galaxy to evolve to our level of intelligence and technology.  This opinion is based on information about just how much needs to happen to allow for the spark of life in conjunction with the apparent rarity of our own solar system.  The recent study Relative likelihood for life as a function of cosmic time seems to confirm this idea.

A basic premise is that life requires stars for two different purposes.  The study states,

Life requires stars for two reasons. Stars are needed to produce the heavy elements (carbon, oxygen and so on, up to iron) out of which rocky planets and the molecules of life are made. Stars also provide a heat source for powering the chemistry of life on the surface of their planets.^[001]

This means that rogue planets aren't likely to spark or support life.  This also means that Population III and most Population II stars systems will not have life either, because they are unlikely to have the elements necessary to form terrestrial planets.  That pretty much leaves us with Population I stars.

Rogue planet, artist concept

Population III or II stars, artist concept

What's all this about "Population"? It's a name for stars at various stages of galaxy development.  

• Population III stars are the stars that likely formed right after the Big Bang.  They have not been directly observed in our Galaxy, so their existed is estimated.  They were made up of mostly Hydrogen and Helium.  As such, they are unlikely to have any planets.
• Population II stars are stars that are still made up of mostly Hydrogen and Helium, but have higher concentrations of elements such as Oxygen, Silicon, Neon, etc.  Typically, such star systems are still unlikely to contain terrestrial planets.  Many Population II stars still exist in our galaxy, though in regions without access to many heavier elements.
• Population I stars are stars that are yet again still made up of mostly Hydrogen and Helium, but have much higher concentrations of the more stable element Iron and other heavy elements.  Population I star systems are much more likely to contain terrestrial planets.  The Sun (Sol) is a Population I star.

Why is this discussion about "Populations" important to the discussion about the arrival of human-like intelligence?  At the risk of oversimplifying this a bit, I'll state that Population III stars lead to the formation of Population II stars, and Population II stars lead to the formation of Population I stars.  As each generation of stars lived out their lifespans, they made way for the next generation to arise.  Population I stars could not have formed 13.5B years ago; there weren't enough heavy elements around.  Just as today, it is extremely unlikely that Population III stars could arise now; there's too much heavy elements around.

Life is very unlikely to have occurred until Population I stars formed and supported terrestrial planets.  Terrestrial planets in the Goldilocks Zone around their star then had to have the necessary events and composition to allow for the spark of life to occur, and subsequently support life until species of higher intelligence evolve.

Is Earth ahead of the curve for the development of life?

The previously mentioned study suggests that Earth may have developed life to the human-level a bit earlier than average.  The study concludes that, "life around low mass stars in the distant future is much more likely than terrestrial life around the Sun today."^[001]  Life throughout the galaxy may be far more common billions of years from now than it is today.  That also means that there may not be any/many other alien species with which we can contact and interact right now.  The study puts our odds at 0.1%.^[001]

This could explain why we've not seen evidence of extraterrestrial intelligent life in our galaxy.  Maybe we are among the very first. Others like us are so rare, we will not be able to contact each other.

Maybe a billion years from now, a future intelligent species will evolve on some future (yet to exist) world, and when they point radio telescopes into their  night sky, they receive a song of hundreds of thousands radio signals from just as many other civilizations.  Maybe, if our species is able to continue evolving, our long-from-now-posterity becomes the evil invaders of other worlds, rather than our world being the one constantly invaded, as Hollywood would have us imagine.  Maybe we are the monsters in waiting.

Response:
Facebook1 and Facebook2
reddit

Article Series:

• Limited lifespan of Habitable Zones around other stars [and a loosely held secret finally revealed about me]
• Small stars may have stable Habitable Zones, but habitable planets might not be common there
• Habitable Planets around White Dwarfs
• Habitable Worlds Around Binary Star Systems might not match Sci-fi
• How many Earth-like planets are orbiting Sun-like stars?
• First round of life in the Universe might have been possible extremely early
• Factors a planet needs for suitability of life; perhaps
• "Goldilocks zone of metallicity" on a galactic scale
• Maybe we are the first

"Goldilocks zone of metallicity" on a galactic scale

What does the night sky look like to a planet within the Galactic Bulge?  Cool Cosmos describes it as,

Stars in the Galactic Center are so concentrated that they typically are only a few light weeks away from each other. In contrast, our local neighborhood of stars are separated from one another by light years. If we found ourselves on a planet near the Galactic Center, our nighttime sky would light up in a blazing display every night, filled with stars as bright as the planet Venus looks to us.^[001]

However, would there be a habitable planet from which to see this sight?  Is it possible to have life-supporting planets near the Galaxy's center?

The concept of Habitable Zones around stars has been studied for a couple of decades.  Life similar to ours can only exist on planets that are a certain distance from their sun.  This is due to the amount of energy from the sun that is received by the planet.  Too much energy, the planet is too hot.  Too little energy, the planet is too cold, hence the Goldilocks reference.

There's another type of Habitable Zone at the galactic scale which uses a somewhat different set of criteria.  Solar systems which have planets that can support life must themselves be made from material that has a lot of elements that are heavier than Helium.  In astronomy, elements heavier than Helium are often referred to as metals.  Metal content of a star is called its metallicity.  The danger is that is if a solar system is made from material that is too rich in metallicity, Earth-sized planets may not be able to exist due to the likelihood of much larger (heavier) worlds displacing those Earth-size planets.  Hence, "Goldilock zone of metallicity" is the idea that certain regions of a galaxy may be too metal-rich and other regions may be metal-poor in order to allow for the presence of Earth-like worlds.^[002]

It's not just the metals

Metallicity is not the only factor, however.

Early intense star formation toward the inner Galaxy provided the heavy elements necessary for life, but the supernova frequency remained dangerously high there for several billion years.^[002]

If a solar system is too close to the galactic core, the intense supernova frequency in a young galaxy might've keep many worlds from supporting life.  This is because they would have experienced numerous blast waves, cosmic rays, gamma rays and x-rays that are fatal to lifeforms.^[002]  As the collective of solar systems age and die, they would have contributed to increasing metallicity.  This means, the right conditions for life on Earth-like planets may have never happened near the galactic core.  Stars that are too close to the galactic core never had and never will have the right conditions to support Earth-like worlds with Earth-like life.

Where can solar systems with habitable planets reside within the Milky Way?  According to the study The Galactic Habitable Zone and the Age Distribution of Complex Life in the Milky Way, the inner bulge component, diffuse halo component, and a thick disk component of our Milky Way Galaxy would not likely allow for Earth-size planets to exist within the right timeframe.^[002]  So, the Habitable Zone of our Milky Way Galaxy isn't even really based on distance from the galactic core.  It's a somewhat washer-shape region in between all the places that Earth-sized planets cannot exist within solar systems.

Current Habitable Zone of Milky Way 

Given all of these factors, the authors of the study The Galactic Habitable Zone and the Age Distribution of Complex Life in the Milky Way state,

We identified the Galactic habitable zone (GHZ) as an annular region between 7 and 9 kiloparsecs from the Galactic center that widens with time and is composed of stars that formed between 8 and 4 billion years ago.^[002]

Knowing our Milky Way's Habitable Zone helps us in the search for life on other worlds.  We can focus more efforts on this space.  This isn't to say that this is the only space where life can and does reside.  The Galactic Habitable Zone is just our safest bet for finding evidence of life.

Primary reference:
C. H. Lineweaver,Y. Fenner, B. K. Gibson, Science 303:59–62, DOI: 10.1126/science.1092322, The galactic habitable zone and the age distribution of complex life in the Milky Way

Response:
Twitter
Facebook 1
Facebook 2
reddit
meneame

Article Series:

• Limited lifespan of Habitable Zones around other stars [and a loosely held secret finally revealed about me]
• Small stars may have stable Habitable Zones, but habitable planets might not be common there
• Habitable Planets around White Dwarfs
• Habitable Worlds Around Binary Star Systems might not match Sci-fi
• How many Earth-like planets are orbiting Sun-like stars?
• First round of life in the Universe might have been possible extremely early
• Factors a planet needs for suitability of life; perhaps
• "Goldilocks zone of metallicity" on a galactic scale
• Maybe we are the first