From what the planet itself is, to whether it came be a place we live on in the future,
join us as we explore the finding of TOI 700 D!
So, let's just jump right in, shall we?
"NASA’s Transiting Exoplanet Survey Satellite (TESS) has discovered its first Earth-size
planet in its star’s habitable zone, the range of distances where conditions may be
just right to allow the presence of liquid water on the surface.
Scientists confirmed the find, called TOI 700 d, using NASA’s Spitzer Space Telescope
and have modeled the planet’s potential environments to help inform future observations."
I know I just unloaded a massive amount of information on you, so let's just break it
down step by step.
The TESS is a satellite that is also a massive telescope, it's job is to find planets that
could be life-filled, but also find ones of a certain size.
You know what?
Here's the NASA description of it: "The Transiting Exoplanet Survey Satellite
(TESS) is a NASA-sponsored Astrophysics Explorer-class mission that is performing an all-sky survey
to search for planets transiting nearby stars.
The primary goal of TESS is to discover planets smaller than Neptune that transit stars bright
enough to enable follow-up spectroscopic observations that can provide planet masses and atmospheric
compositions."
So yeah, the TESS is supposed to find planets that we can study and hopefully determine
whether they are able to support life, or more importantly, support us.
The discovery of TOI 700 D is VERY important because it's literally the first planet it
has found (and trust me there are plenty of planets it's found so far) that fits the needs
of life itself!
Or at least, is the most like Earth in the grand sense of things.
So you can imagine why a lot of scientists are interested in learning more and more about
this planet as a whole.
Now if you don't recall what "habitable zone" means, it's about distance from the sun, or
more specifically, "the orbital region around a star in which an Earth-like planet can possess
liquid water on its surface and possibly support life."
Think about it in terms of our own solar system.
The Earth is within the habitable zone of our sun, thus we're able to live, have water,
have an atmosphere that allows us to be hot and cold without being on either extreme,
and so on and so forth.
But, if you look at Venus, because of its proximity to the sun, it's a LOT hotter, and
thus it suffers from the Greenhouse Effect, where gasses fill up its atmosphere to such
a degree that it's really hot on the surface.
So hot that it melts metals.
Meanwhile, on Mars, it's so far away from the sun that it's usually REALLY cold, so
cold that no life can survive there (that we know of...) and the water that is there
is frozen in ice at the polar caps.
That habitable zone is what we define as the "must be there" zone in terms of planets we'd
like to try and colonize, or even just expect life to be on.
Because if it's not in that zone, it usually is an ice world, a storm world, a gas planet,
or something in between.
Heck, there are even planets within the habitable zone of a star that don't always meet the
requirements of life.
But we still look in that zone because it's the best chance of finding things there.
And since TOI 700 D is in that zone AND is Earth-sized, it might just be something special.
Emphasis on MIGHT, because as you all have hopefully learned over the course of your
lives...you can't judge a book by its cover.
And in this case, you can't judge a planet because it looks like it might be an Earth-like
planet, or might be the same size as Earth.
Because in the planet-finding race, it's not just the planet you need to worry about, it's
the sun too.
After all, our yellow dwarf star is a big reason why we exist right now.
It's the right type of star to support life as a whole.
It gives us the right amount of sunlight, heat, and tether in regards to our orbit to
allow us to live.
For TOI 700 D?
It doesn't technically have that.
It is in the habitable zone, but there are a few things different from its star than
ours.
Before we dive into more of this topic, be sure to like the video and subscribe to the
channel, that way you don't miss any of our weekly videos!
Primary among the differences of these stars is that the star near TOI 700 D is a "red
dwarf star".
Which if you don't know is the smallest star type in the Milky Way galaxy.
But in a twist, it's also the one that is the most popular in terms of numbers in the
galaxy.
So why don't we see more of them?
Because they're the type of star to not emit so much light that you can see them across
the galaxy.
So if you look up at the night sky, you're not going to see any red dwarf stars.
But there's a catch in that, while they don't emit as much light or heat as our own sun,
they're most stable kind of star in our galaxy.
Meaning that radiation bursts, solar flares, and more don't happen on the star.
So, if a planet is near one of these stars, like TOI 700 D, that would mean it wouldn't
be in danger of having a dangerous flare event happening and burning up the atmosphere or
bombarding it with radiation.
Both of which could be world-ending events: “In 11 months of data we saw no flares from
the star, which improves the chances TOI 700 d is habitable and makes it easier to model
its atmospheric and surface conditions,” says Emily Gilbert, a graduate student at
the University of Chicago.
So yeah, that is something in favor of the planet.
But, there are more catches here, not the least of which is that based on what we've
seen on the planet, it's one that is tidally locked with its sun.
To be tidally locked means that the planet is only facing the sun halfway, it never rotates
itself in a way that helps it turn away from the sun.
So thus, there is a literal "line" down the planet, one side always faces the sun, and
one side doesn't.
Usually, this would mean that the temperatures on the planet are extremely hot on one side
and extremely cold on the other.
But because this is a red dwarf star, that may not be the case.
Not enough heat and light are produced from it and reach the habitable zone to make that
kind of thing happen...that we know of.
In fact, when NASA first discovered TOI 700 D, they brought in an expert on the subject
of simulations and whether planets and their climates would be habitable for humans.
The person worked with NASA and this is what they determined:
"The climate simulations our NASA team has completed suggest that an Earth-like atmosphere
and gas pressure isn’t adequate to support liquid water on its surface.
If we put the same quantity of greenhouse gases as we have on Earth on TOI-700 d, the
surface temperature on this planet would still be below freezing."
Now, that may sound like a death sentence for the planet, but it's not, not in this
area anyway.
Because while a planet may be "below freezing" in terms of temperature...that's not uninhabitable.
Plus, these are just simulations, they technically can't prove anything other than the expectations
based on our knowledge of worlds and how they form.
The bigger nail in the coffin of this particular planet is the distance, as it's 100 light
years away from us, but that's a topic for a later time.
The point here is that whether we like it or not, this planet may SEEM like Earth in
some ways, but it's missing key points that make it a perfect Earth "replica":
“No matter what we find out about the planet, it’s going to look completely different
from what we have here on Earth,” says Gabrielle Engelmann-Suissa
Just how much different?
Well, how about two examples of what this planet may just be?
An ocean-covered planet: a dense, carbon-dioxide-dominated atmosphere much like a young Mars, with a
deep layer of clouds on the star-facing side.
A cloudless, all-land version of modern Earth: winds flow away from the night side of the
planet and converge on the point directly facing the star.
Not intolerable, but not exactly what we'd like to live on, am I right?
Naturally, this discovery was a big deal, and since it was a potentially "ground-breaking"
planet discovery, the team wanted to make sure that they had the science and the math
to prove that this was what they said it was.
“Given the impact of this discovery—that it is TESS’s first habitable-zone Earth-size
planet—we really wanted our understanding of this system to be as concrete as possible,”
says Rodriguez.
“Spitzer saw TOI 700 d transit exactly when we expected it to.
It’s a great addition to the legacy of a mission that helped confirm two of the TRAPPIST-1
planets and identify five more.”
So even with the somewhat downfalls that could lead us away from TOI 700 D, this is still
a big discovery for TESS and the team working on it with NASA and others.
In fact, it proves all the more that things like TESS are necessary.
Because there are potential Earth-like planets that are out there, even if a majority of
them have faults that lead them to being something much different than our Earth.
That just means we need to look harder at what's out there, and through things like
TESS, we have that option.
You might be asking right now, "Wait a minute, if the one we're looking at is "D", doesn't
that mean there are A-C that could work too?"
Technically yes, but those planets aren't in the habitable zone of the star, and thus
are unlivable in a variety of ways.
Again, timing and placement is everything.
Which brings us too, "Ok, so this planet is a bust, is there any other planets out there
that could be Earth-like?"
And the answer to that is also yes, we have found planets that COULD be a place for us
to live on.
But, like always, there are catches.
For example, the planet that everyone thinks is the "next Earth to live on" is a planet
called Alpha Centauri.
A planet that has characteristics close to Earth and could be a place we live on one
day.
Keyword here is "one day", that's because right now Alpha Centauri is 4.2 light years
away.
While that may sound small, if we were to try and reach it in our fastest craft's speed,
we'd get there...in about a couple tens of thousands of years...if we were lucky.
That's not quick, at all.
So much so that you might be questioning why we would even want to try and find planets
like TOI 700 D (which again is 100 light years away and thus MUCH farther away than Alpha
Centauri) if there is "no chance" of reaching them.
The answer to that is simple, yeah, we might not reach them right now, but there is hope
to reach them one day.
Think about in terms of Star Trek, which is very much based on Earth, just a future Earth.
By their own admission, the fact that Star Fleet existed at all was because of great
advances in technology that happened for them over the course of time, which is exactly
where we're at right now.
If you told someone in the year 1920 that we would be able to fly all over the world
with easy in giant metal planes that weighed many tons, they'd laugh at you.
If you told them that one day they'd be able to put computers in the palm of their hands
and be able to look up all sorts of information...they wouldn't even know what a computer is.
100 years can make a lot of difference in people's lives, especially when it comes to
technology.
Even right now, there are scientists who are working hard to try and make the next generation
(Engage!) of starship.
Including making engines that could allow us to go at least close to the speed of light,
if not faster.
There's even a project right now called Longshot (yes, the name is ironic) that is aiming to
use an advanced kind of technology to take a craft to Alpha Centauri in only a couple
of years time versus tens of thousands!
So clearly we've got "top men" on this!
Thus why TESS and other satellites, probes, and more are needed.
After all, if we get the way to get there, we need to know where to go.
Especially if we need to do research on whether it's habitable at all.
We're very much on the outside looking in, but, if we can get closer?
Yeah, the sky is the limit here.
TOI 700 D may or may not be what we're looking for in terms of a planet that we can live
on.
But it's close, may not "close enough", but it's close.
It's an Earth-sized planet in the habitable zone of a star, and if there is one like that,
there could be one that's even closer to what we need to live on another Earth.
And that is enough hope to get many people to look for more planets among the stars.
Thanks for watching everyone!
What did you think of this look at TOI 700 D and whether it might just be the next planet
that has life on it?
Do you think that it'll be everything that we hope for and more?
Or do you think that there's something lurking within it that'll deter us from trying to
get there one day?
Let me know in the comments below, be sure to subscribe, and I'll see you next time on
the channel!