Tag: Earth

That Time NASA Discovered Life on Earth

~ J.S. Pailly ~ 10 Comments

Hello, friends!

As some of you may already know, there is life on Earth.  NASA discovered that fact in 1990.  Let me explain.

In the decades prior to the Space Age, certain astronomers had claimed to observe vegetation growing on the Moon, artificial canals on the face of Mars, and some scientists even speculated that beneath the clouds of Venus (which were surely H2O clouds), we might find a world dense with jungle.  Writers and philosophers had long speculated about how other worlds might be populated by other people, and at least a few theologians argued that there must be life on other planets (for why would God create all these planets and then leave them empty?).

And yet, as both the Soviet and American space programs ventured farther and farther out into space, they found nothing.  No vegetation on the Moon (not even on the far side of the Moon).  No canals on Mars.  Definitely no jungles on Venus (and as for Venus’s clouds, it turns out they’re not made of H2O—they’re not made of H2O at all!!!).

I don’t want to make it sound like everybody expected to find life on the Moon, Mars, or elsewhere, but a lot of people were expecting to find life.  So what happened?  Why couldn’t our space probes find life on any of the other worlds of the Solar System?  There were two possible explanations.  Either there was no life out there to find, OR something was wrong with our space probes.  Maybe they weren’t carrying the right equipment to detect life, or maybe they weren’t performing their experiments properly, or maybe they weren’t sending the correct data back to Earth.

Which brings us to 1990.  NASA’s Galileo spacecraft was heading out to Jupiter, but for navigational reasons it needed to do a quick flyby of Earth first.  A certain scientist named Carl Sagan saw this Earth flyby as an opportunity.  What would happen if Galileo did a thorough scan of our home planet?  Could this fairly standard NASA space probe, equipped with a fairly standard suite of scientific instruments, detect life on a planet where we already knew life existed?

The results were published a few years later in a paper entitled “A search for life on Earth from the Galileo spacecraft.”  This “search for life on Earth” paper is my all time favorite scientific research paper.  First of all, for a scientific paper, it’s a surprisingly easy read.  Turns out Carl Sagan was a good writer with a knack for explaining science in a clear and accessible manner.  Who knew?  Secondly, the experiment itself is really cool.  And third, the results of the experiment are a little more ambiguous than you might expect.

Among other things, Galileo detected both oxygen and methane in Earth’s atmosphere.  If you didn’t already know there was life on Earth, it would be difficult to explain how those two chemicals could both be present.  Oxygen and methane should react with each other.  They should not exist together in the same planet’s atmosphere for very long—not unless something unusual (like biological activity) continuously pumps more oxygen and more methane into the atmosphere.

Additionally, Galileo noticed a strange “red-absorbing” substance widely distributed across Earth’s landmasses.  This mystery substance could not be matched with any known rock or mineral, suggesting a possible biological origin.  This red-absorbing mystery substance was, in fact, chlorophyll—the chemical that allows plants to perform photosynthesis.

And lastly, Galileo picked up radio transmissions.  Galileo couldn’t determine the content of these transmissions, but the transmissions were clearly artificial—an indication that there is not only life but intelligent life on Earth.

I’ve read this “search for life on Earth” paper several times over the years.  Like The Lord of the Rings or Ender’s Game, it’s one of those things I love to read again and again, and each time I feel like I get a little more out of it.  The main take away, I have come to believe, is that if there were anything similar—anything even remotely similar—to Earth’s biosphere on the Moon or Mars or anywhere else in the Solar System, we would know about it.  Our space probes would absolutely be able to detect something like that.

However, there’s still a lot of stuff here on Earth that the Galileo probe missed.  Some little details, for example: chlorophyll absorbs both red and blue light, but Galileo apparently didn’t notice the blue absorption.  Only the red.  And Galileo overlooked some big things, too.  Cities, roadways, the Great Wall of China?  Maybe a follow-up mission to Earth would find those things, but Galileo didn’t see any of that stuff.  And then there’s Earth’s oceans.  Galileo couldn’t detect anything beneath the surface of the water.  Water very effectively blocked all of Galileo’s sensors.

So our space probes are not fundamentally flawed, but they do have a few blind spots.  Today, no one expects to find jungles on Venus or canals on Mars.  Our space probes say those things aren’t there, and we can be confident that our space probes are working properly.  But there are a few niche environments out there were alien life might still be hiding.

WANT TO LEARN MORE?

Science communicators (myself included) dumb things down for their readers, which is why reading actual scientific papers has become an important part of my research process.  Dumbed down science is fine, provided it still says what the actual scientific research says.  But reading these sorts of papers is a skill, and it takes some time and practice to do it.  If you’ve ever wanted to start reading scientific papers for yourself, “A search for life on Earth from the Galileo spacecraft” by Carl Sagan et al. is a good starter paper.

NASA’s DART Mission: Brace for Impact!!!

~ J.S. Pailly ~ 12 Comments

Hello, friends!

We are only a few days away from what is, in my opinion, the #1 most important space story of the year.  No, I’m not talking about the launch of Artemis 1.  And no, this has nothing to do with the Webb Telescope either.  I’m talking about NASA’s DART Mission.

For eons now, asteroids have been zipping and zooming past our planet.  Every once in a while, one of those asteroids will hit our planet, causing anywhere from minor to major to global mass extinction event levels of damage.  But on Monday, September 27, 2022, humanity will perform our first ever experiment to see if it’s possible to smack an incoming asteroid away.

The asteroid in question is named Dimorphos.  Dimorphos is not actually a threat to us, but if we’re going to perform an experiment like this, Dimorphos is a rather convenient target for target practice.  That’s because Dimorphos is not just an asteroid; it’s also a moon (or should I call it a moonlet?) orbiting a larger asteroid named Didymos.

When the DART spacecraft crashes into Dimorphos, the force of the impact will change Dimorphos’s orbit around Didymos.  It should be fairly easy for astronomers to measure this change, and thus it should be fairly easy to judge how effective DART was—and just how effective DART would have been against an asteroid that was actually threatening us.

Oh, and just in case anyone’s concerned that DART might accidentally knock Dimorphos out of its original orbit entirely and send it hurtling our way, thus ironically causing the very disaster this mission was meant to help prevent—don’t worry.  Didymos’s gravitational hold on Dimorphos is strong.  No matter what happens on this mission, Didymos is not going to let her little moonlet go (another reason why Dimorphos was selected as the target for this experiment).

So on Monday, September 27, 2022, there will be a head-on collision between an asteroid/moonlet and a NASA spacecraft.

An Italian-built spacecraft named LICIACube will be positioned nearby to observe the experiment.  A multitude of Earth-based telescopes will also be watching.  The European Space Agency also plans to send a follow-up mission (named Hera) in 2026, to check up on Dimorphos after its post-impact orbit has had some time to settle down.

Life on Earth has never been able to defend itself from incoming asteroids before.  Life on Earth has never had the ability to even try, until now [citation needed].  Obviously asteroids are not the only threat to life on our planet.  Obviously this is not the only challenge we need to overcome.  But the DART Mission is a huge first step.  A true giant leap.  No, DART probably won’t get the same kind of love and attention as Webb or Artemis 1, but still I’d say this is the #1 most important space story of the year.  This may be one of the most important science experiments in all of Earth history.

WANT TO LEARN MORE?

P.S.: I said life on Earth has never before had the ability to defend itself from incoming asteroids.  Technically speaking, we cannot be 100% sure that’s true.  Click here to read my post on the Silurian Hypothesis.

Sciency Words: Critical Zone

~ J.S. Pailly ~ 2 Comments

Hello, friends!  Welcome to Sciency Words, a special series here on Planet Pailly where we take a closer look at the definitions and etymologies of science or science related terms, in order to expand our scientific vocabularies together.  In today’s post, our Sciency Word is:

CRITICAL ZONE

So I could make this post about climate change, but I won’t.  Certain people would just get angry with me in the comments, and I’m not in the mood for that today.  So instead, I’m going to talk about Earth’s “critical zone” as something that could be relevant to astrobiological research.

Definition of Critical Zone: In Earth sciences, the critical zone is the surface and near surface environment of our planet—in other words, it’s the part of our planet where life lives.  The proper scientific study of Earth’s critical zone will require an interdisciplinary approach, combining geology, biology, hydrology, and other related fields.

Etymology of Critical Zone: The term was first introduced in 1998 by American sedimentary geologist Gail Ashley.  She called it the critical zone because, in her words, “it’s critical for life” and also because it is “critical to know more about it.”  (Source: see the Eos article in the links below.)

Here’s a fun fact that I like to share at parties: there are somewhere between four and five thousand different minerals found here on Earth.  Four to five thousand!  Other planets in our Solar System are known to have only a few hundred, at best.

Why is Earth so mineralogically diverse?  Plate tectonics, for one thing.  Liquid water plays an important role as well.  Some minerals can only form in the presence of liquid water.  But the biggest factor, by far, is life.  Living things do lots of weird chemistry, and all that weird chemistry messed with the planet’s soil and bedrock. Earth’s biosphere affects Earth’s geology.  And Earth’s geology, in turn, affects Earth’s biosphere.  There’s a synergistic relationship between living things and non-living rocks on this planet—and that is what the concept of Earth’s critical zone is all about.

I feel this is a terribly important concept to understand as it relates to Earth.  It’s also something worth bearing in mind as we think about other worlds out there, worlds which may or may not support life of their own.

WANT TO LEARN MORE?

I’m going to recommend this article from Eos, entitled “Critical Zone Science Comes of Age.”  I think that article is a pretty good summary of how critical zone research started and how it’s going, and it includes some quotes from Gail Ashley explaining what she was thinking about when she originally coined this term.

I’m also going to recommend this brief article entitled “‘Critical Zones’ on Mars and Across the Solar System,” which attempts to adapt the concept of the critical zone for other worlds.

And if you want to read more about why Earth is so mineralogically diverse, here’s a piece from EarthDate.org entitled “Minerals Evolve, Too.”

Our Place in Space: An Immature Technosphere

~ J.S. Pailly ~ 14 Comments

Hello, friends!  Welcome to Our Place in Space: A to Z!  For this year’s A to Z Challenge, I’ll be taking you on a partly imaginative and highly optimistic tour of humanity’s future in outer space.  If you don’t know what the A to Z Challenge is, click here to learn more.  In today’s post, I is for…

AN IMMATURE TECHNOSPHERE

In a previous post, I told you about the DART Mission, our first real experiment to see if we can defend our planet from incoming asteroids.  I believe humanity has a tremendous responsibility to protect our planet, not only for our own benefit but for the benefit of the entire Earthly biosphere.  Incoming asteroids can do serious harm to Earth’s biosphere (just ask the dinosaurs).  But, of course, there are other threats to the biosphere that should concern us—more immediate and urgent threats, too.

The term “immature technosphere” is mainly associated with SETI research.  Imagine, if you will, a planet that is home to alien life.  Over cosmic timescales, we might expect this hypothetical alien planet to go through several phases of development.

Phase One: The Immature Biosphere
Life has begun!  The first microorganisms are swimming around in the planet’s water (or whatever liquid this planet has instead of water).  But biological activity produces biological waste, in one form or another, so as these early organisms multiply and spread, they may end up poisoning their own environment with their own waste products.

Phase Two: The Mature Biosphere
Life has found a way.  A variety of organism have now evolved, and the waste produced by one organism serves as fertilizer, food, or fuel for others.  A natural balance has been achieved.  Natural cycles have emerged.  Life not only survives but thrives!

Phase Three: The Immature Technosphere
Intelligent life has emerged, by which I mean life capable of creating and using technology.  But as these intelligent life forms begin using technology on a grander and grander scale, they may inadvertently disrupt the natural cycles and the natural balance of their world.  Life is threatened once again, this time by technological waste.

Phase Four: The Mature Technosphere
If intelligent life is truly intelligent, it will recognize the harm it is doing to its own environment and start inventing ways to undo that damage, or at least to keep the damage in check.  In time, perhaps a new balance will be achieved, with nature and technology working together in harmony.

Turning our attention back to Earth, I think it’s fair to say our planet is in the “immature technosphere” phase of development.  But an immature technosphere today implies that a mature technosphere may develop later on, and that gives me hope.

I keep saying that this “Our Place in Space” series is a highly optimistic view of humanity’s future.  Part of what I mean by that is that we will not leave Earth behind.  We will not make a new home for ourselves on the Moon or Mars or elsewhere after destroying our first home here on Earth.  I doubt that that would work anyway; any off-world colony we might establish would still be dependent on Earth for a long, long time to come.

I know a lot of people who see the state of the world and despair.  Things are bad right now, and some of the damage we are doing to our planet and to each other cannot be undone.  But a better future is still possible.  Humanity just needs a bit more time to mature.

Want to Learn More?

Earth in Human Hands by David Grinspoon is one of my all time favorite books.  It’s certainly my #1 favorite non-fiction book.  As an astrobiologist, Grinspoon has more knowledge and authority on scientific matters than I do, but his view of the future is much like the view I’ve been presenting in these A to Z Challenge posts.

So if you’re worried about the state of the world and you want to believe that a better and brighter future is still possible, I highly recommend picking up Grinspoon’s book.

Our Place in Space: The Aldrin Cycler

~ J.S. Pailly ~ 23 Comments

Hello, friends!  Welcome to Our Place in Space: A to Z!  For this year’s A to Z Challenge, I’ll be taking you on a partly imaginative and highly optimistic tour of humanity’s future in outer space.  If you don’t know what the A to Z Challenge is, click here to learn more.  In today’s post, A is for…

THE ALDRIN CYCLER

Even in the future, space travel will be expensive.  True, new technologies should make it less expensive than it is today, but there’s one problem that will never go away, no matter how advanced our technology gets: gravity.

Anywhere you want to go in space, you’re going to have to fight against gravity to get there: Earth’s gravity, the Sun’s gravity, the gravity of other planets and moons—at some point on your journey, you’re going to have to fight against any or all of these gravitational forces.  And fighting gravity uses up fuel.  Lots and lots and lots of fuel.

And yet, despite the unforgiving and unrelenting force of gravity, human civilization will eventually spread out across the Solar System.  I’m not going to tell you it will happen in the next twenty years.  I won’t tell you it will happen in the next century, even.  But someday, it will happen.  I’m sure of it!  And so today, I want to talk a little about what the future transportation infrastructure of the Solar System might be like.

American astronaut Buzz Aldrin is, of course, most famous for being the second person to set foot on the Moon.  Aldrin is also a highly accomplished scientist and engineer.  In 1985, he did some math and discovered a very special orbital trajectory that would make traveling from Earth to Mars (and also from Mars back to Earth) far more fuel efficient.

The term “Aldrin cycler” refers to that very special orbital trajectory Aldrin discovered.  The term can also be used to describe a spacecraft traveling along that special orbital trajectory.  The initial investment to build an Aldrin cycler (the spacecraft, I mean) would be really high.  We’d probably want to build a rather large spacecraft for this, and once it’s built, maneuvering the thing into the proper trajectory would require a stupendous amount of fuel.

However, once we’ve done all that, the cycler will cycle back and forth between Earth and Mars, over and over again, pretty much forever.  Traveling to Mars would be a little like catching a train.

I was going to have the Aldrin cycler make a “choo-choo” sound, like I train, but then I realized that would be silly.  Things don’t make sounds in outer space.

Passengers would board the cycler as it flew past Earth; about five months later, they’d disembark and head down to the surface of Mars.  The cycler would then take a long journey (about twenty months) looping around the Sun before flying past Earth once more; then the “cycle” would begin again.

The trip from Earth up to the cycler would still require some amount of fuel.  So would the trip from the cycler down to the surface of Mars.   The cycler itself would also require a little bit of fuel for maneuvering thrusters; otherwise, over time, the ship could start to drift ever so slightly off course.

Obviously this is not a cost-free form of space travel, but I’m sure you can see how this could help keep the cost of space travel down.  And so I imagine in the distant future, the Aldrin cycler (or something very much like it) will be a key part of the Solar System’s infrastructure, just as trains are an important part of our modern day infrastructure here on Earth.

Want to Learn More?

Click here to see a short animation of the Aldrin cycler orbital trajectory, showing several cycles worth of Earth-to-Mars and Mars-to-Earth journeys.

I’d also recommend Buzz Aldrin’s book Mission to Mars: My Vision for Space Exploration, where Aldrin describes the Aldrin cycler (and other cool Mars related things) in more detail. Click here to see the book’s listing on Amazon.

A to Z Theme Reveal: Our Place in Space!

~ J.S. Pailly ~ 16 Comments

Hello, friends!  April is almost here, which means it’s almost time for the A to Z Challenge!  If you haven’t heard of the A to Z Challenge before, click here to learn more.  It’s a cool thing, with lots of blogs participating, covering all sorts of fun and interesting themes.  Here on Planet Pailly, the theme for this year’s A to Z Challenge will be:

OUR PLACE IN SPACE!!!

This will be a mostly imaginative tour of the future, with a little bit of actual, factual science mixed in.  We’ll see how future human colonists are faring on the Moon and Mars, we’ll visit scientific research stations in the outer Solar System, and perhaps we’ll witness humanity’s first tentative steps toward interstellar travel.  We’ll also check in on Earth and see how our home planet is doing.

I can also promise you that this will be an optimistic view of the future.  I am, and always have been, optimistic about the future of humanity.  People have told me before that my optimism is foolish and naive.  People have told me to “look at the direction things are going” and that I should “get ready for what’s coming.”  Maybe those people have a point, but when I talk about the future, I’m not quite as foolish and naive as I may seem.

I know the world is a scary place right now.  There’s a really nasty war going on.  There’s a pandemic going on (still).  Around the world, liberal democracies are under threat, and climate change is transitioning from being a theoretical concern to a very real and very immediate problem.  The gap between the rich and poor is growing wider, our population growth is unsustainable, et cetera, et cetera… I know.  Believe me, I know.  And yet despite all of that, I still have hope for our planet and our species.

Mother Earth (as pictured above) is right.  We can do better than this.  The first step is to believe in ourselves, to believe that a better and brighter future is still possible.  I admit that hope alone will not guarantee us a better or brighter future, but I also know from personal experience that hopelessness is a self-fulfilling prophecy.  Those who still have hope still have a chance while those who give up hope have doomed themselves.  Let us not, as a species, give up hope in ourselves.

So in the coming month, I invite you to join me in imagining a future where kindness has prevailed, a future where we have not destroyed ourselves or our planet, and where we, as a species united in peace, have gone on to claim our rightful place in space.

Is There Life on Earth?

~ J.S. Pailly ~ 5 Comments

Hello, friends!

Let’s imagine some space aliens are cruising by our Solar System.  They turn their scanners on our planet and see… what?

Among other things, they’d notice that Earth’s landmasses are partially covered with a strange, green-colored substance.  Of course, you and I know what that green substance is.  It’s chlorophyll.  But would those extraterrestrial observers, who have no prior knowledge of our planet, be able to figure that out?  Even if they did, would they realize what chlorophyll is used for?  Maybe.  Probably not, though.

Which brings me to my all-time favorite scientific paper: “A search for life on Earth from the Galileo spacecraft,” by Carl Sagan et al.  I love this paper in part because it’s so clearly and concisely written, with jargon kept to a minimum.  Sagan was, after all, a talented science communicator.  But I also love this paper because its conclusions are so shocking, so eye-opening.

In 1990, NASA’s Galileo spacecraft turned all its high-tech instruments toward Earth and detected… not much, actually.  Galileo did pick up radio broadcasts emanating from the planet’s surface.  Aside from that, though, Galileo’s data offered highly suggestive (but also highly circumstantial) evidence on Earthly life.  The lesson: finding life on other planets is hard.  Even using our very best equipment, it was hard for NASA to detect signs of life right here on Earth!

At least that’s what I got out of reading Sagan’s Galileo experiment paper.  And based on various commentaries I’ve read or heard about this paper, that seems to be the lesson other people got out of it too.  So I was surprised to hear Sagan himself, approximately seven-and-a-half minutes into this interview, saying the exact opposite.

We’ve flown by some sixty worlds.  We claim that we haven’t found life anywhere, and that that is a significant result.  That is, that we would have found life had it been there.  But this has never been calibrated.  We’ve never flown by the Earth with a modern interplanetary spacecraft, all instruments on, and detected life here.  And so Galileo, because of this peculiar gravity assist VEEGA trajectory, permits us to do that.  And as I’ll describe tomorrow, we find life five or six different ways, including intelligent life.  And this then means that the negative results that we find elsewhere are, in fact, significant.

I’ve been puzzled by this for a while now, but I think I’ve finally figured out why Sagan would say this.  It’s politics.

On the one hand, scientists need to understand the challenges they’ll face (including the limitations of their own equipment) in searching for life on other worlds.  That really is, I think, the purpose of the Galileo experiment paper.  On the other hand, it would not do to say on public television, to cantankerous taxpayers and the listening ears of Congress, that NASA spends millions of dollars on space probes that are not even capable of detecting life right here on Earth.

Space exploration is expensive.  And like all expensive types of research, sooner or later the researchers involved have to learn how to play politics.

What Color are All the Planets?

~ J.S. Pailly ~ 11 Comments

Hello, friends!

So as you know, Earth is “the Blue Planet” and Mars is “the Red Planet.”  By my math, that leaves us with six other planets in our Solar System that don’t have color-related nicknames.  Today, I’d like to try and fix that.

Jupiter was the toughest.  He’s actually lots of different colors: red, grey, white, orange… and then the Juno mission recently showed us that Jupiter’s polar regions are blue!  Of course Jupiter is most famous for being red in that one specific spot, but even the Great Red Spot changes colors from time to time, fading from red to pink to white before turning red again.

Anyway, those are my picks for the color-related nicknames for all the planets.  Do you agree with my picks?  Disagree?  Let me know in the comments below!

Sciency Words: Aerobiology

~ J.S. Pailly ~ 2 Comments

Hello, friends!  Welcome to Sciency Words, a special series here on Planet Pailly where we talk about those weird and wonderful words scientists like to use.  Today on Sciency Words, we’re talking about:

AEROBIOLOGY

You will find life pretty much anywhere you go on Earth.  Living things are in the water, on the land, and up in the air.

Aerobiology comes from three Greek words meaning “air,” “life,” and “the study of.”  So aerobiology is the study of airborne life, specifically airborne microbial life.  According to the Oxford English Dictionary, the term was first introduced in the late 1930’s.

I have to confess I am totally new to aerobiology.  I only found out about this term yesterday, and I don’t want anything I say to misrepresent the field.  But based on what I have read, it sounds like aerobiologists are primarily concerned with protecting public health from the spread of pollen and other allergens, as well as the spread of airborne diseases.

However, aerobiologists also study airborne microbes that are not a direct threat to human health—and this is the part that connects to the outer space stuff I normally write about.  For decades now, aerobiologists have known that algae and other common microorganisms can fly up into Earth’s atmosphere and travel great distances on the wind.  And according to this 2001 paper, microorganisms can (and do) remain active—growing and reproducing—inside the water droplets found in clouds.  As the authors of that 2001 paper explain it, we should start thinking of clouds as microbial habitats.

So what does this have to do with outer space?  Well, if clouds on Earth can serve as a habitat for microorganisms, then maybe microorganisms could exist in the clouds of some other planet.

And by some other planet, I mean Venus.

And by maybe, I mean stay tuned for Monday’s post.

Science is Wrong About Everything

~ J.S. Pailly ~ 6 Comments

Hello, friends!  So one day when I was a little kid, I got into a huge argument with another kid in school.  I’d said something about how Earth is a sphere, like all the other planets.  The other kid told me (firstly) that Star Trek isn’t real and (secondly) that the earth is flat.

As evidence, the other kid told me to just look around.  It’s obvious that the world is flat.  If I needed more proof, I could look at a map.  More kids soon jumped into this argument.  They all agreed: the earth is flat, and also I’m a huge nerd for watching so much Star Trek.  I was outnumbered, and being outnumbered was further proof that I must be wrong.

I went home so mad that day.  How could those other kids be so stupid?  I was right.  Everybody else was wrong.  I’m tempted to turn this into a metaphor for Internet culture, but that’s not the point I want to make today.

Yes, when those other kids said the Earth is flat, they were wrong.  But when I said the Earth is a sphere, I was wrong too.  Less wrong, obviously.  But still, I was wrong.

Isaac Asimov’s essay “The Relativity of Wrong” is a brilliant summation of how science works.  It should be required reading for every human being (click here to read it).  As Asimov explains:

[…] when people thought the earth was flat, they were wrong.  When people thought the earth was spherical, they were wrong.  But if you think that thinking the earth is spherical is just as wrong as thinking the earth is flat, then your view is wronger than both of them put together.

As Asimov goes on to explain, there was a time, long ago, when educated people really did believe the world was flat, and they had good reasons for thinking it to be so.  But then discoveries were made.  New knowledge was learned, and people came to think of the world was a sphere.  Then more discoveries were made, and people started to think of the world as an oblate spheroid (round, but slightly bulgy at the equator).  And then still more discoveries were made, and even the oblate spheroid model turned out to be slightly inaccurate.

People (including people on the Internet) will gleefully point out that science has been wrong about stuff in the past; therefore, science could be wrong about stuff today—stuff like evolution, climate change, general relativity—also stuff like vaccinations and COVID-19.  When science is wrong so much, why pay attention to science at all?

Well, it’s true.  In absolutist (this-or-that-ist) terms, science is wrong.  Science is always wrong, about everything, all the time.  Science is full of educated guesses and close approximations of observed reality.  It’s not perfect.  It will never be perfect.  But with each new discovery, science is a little less wrong today than it was yesterday.  And you can trust science to keep being less and less wrong, even if it will never be 100% right.

And that process of constant refinement and improvement, that process of getting closer and closer to the truth—that’s something worth paying attention to, something worth taking seriously, don’t you think?

P.S.: I’ll concede that those kids in school were right about one thing.  I was, and still am, a huge Star Trek nerd.