Are these Planets Found by TESS Better than Earth?
INTRODUCTION
Are you ready to explore the exoplanets beyond our Solar System?
Join us as we take a journey through the latest discoveries of the Transiting Exoplanet Survey
Satellite (TESS).
We'll learn all about the conditions necessary for a planet to be considered habitable and
examine the most important discoveries of TESS.
From the super-Earth of HD 209-458 B to the mysterious Kepler 438B, let's get started!
( roll intro) The search for exoplanets has been a source
of fascination among scientists and the general public alike.
With the launch of TESS, the Transiting Exoplanet Survey Satellite, in 2018, scientists have
been able to identify more than 10,000 potential planets outside our solar system.
For a planet to be considered habitable, it must have water vapor in its atmosphere and
be within a certain temperature range.
It must also have the right amount of gas in its atmosphere for rings to form, and the
right amount of sulfur content for liquid droplets to exist.
--- Launched on April 18th 2018, the NASA TESS
(Transiting Exoplanet Survey Satellite) telescope has commenced searching for planets outside
our solar system.
After decades of research and billions of dollars invested, this telescope scans the
entire sky in both the northern and southern hemispheres, in an effort to find small worlds
that orbit stars other than our own.
So far, the telescope has identified 10 000 such candidates, including planets whose temperatures
are warmer than Mercury, and which sit in the "Goldilocks zone" - a habitable zone where
liquid water can exist on their surfaces.
One of these exoplanets is HD 209-458 B, located 169 light years away, and orbiting a star
that is smaller and cooler than our Sun.
Scientists believe HD 209-458 B contains an atmosphere of water vapor and carbon dioxide,
making it a possible "super Earth".
The primary aim of the mission is to detect planets around bright stars, so that further
characterization and study of the planets and their atmospheres can be carried out.
LIFE FACTORS
So what exactly makes a planet habitable?
1) In order for a planet to be habitable, it must have water vapor in its atmosphere.
Factors like temperature also affect water in a substantial way.
If the temperature is below 100 Kelvin (or 60°F above absolute zero), water vapor condenses
into liquid droplets like on Earth.
Temperatures beyond this range would cause water to exist as solid, or ice.
2) Temperature is another important factor to consider when discussing the atmosphere's
gas composition.
Water vapor has an upper limit of approximately 100 Kelvin (or 60 degrees Fahrenheit), which
is still well below absolute zero.
Air warmer than 35 Kelvin (around minus 186 degrees Fahrenheit) contains gases more likely
to absorb heat and less likely to release it as easily as oxygen and nitrogen do on
Earth.
3) The power of all-sky surveys like Tess has been demonstrated by taking into account
the fact that planets must be rocky and temperate enough to support liquid water, and have enough
but not too much gas in their atmosphere for rings to form.
Sulfur content above 100 Kelvin and 60 degrees Fahrenheit would cause vapor to condense into
liquid drops, and form ice at extremely high temperatures.
All these considerations make it possible to look for planets with habitable atmospheres,
even though it's too soon to call out which specific planet Tess will find.
TESS CANDIDATES
This combination of characteristics makes it possible to look for exoplanets with habitable
atmospheres, with the help of all-sky surveys like TESS.
Notable exoplanets will be discussed now.
Each of these planets are unique in their own right, and all have the potential to be
habitable, making them prime candidates for further exploration.
Let’s go through them one by one.
12) Kepler-7b is an excellent candidate for detailed analysis using a spectrograph due
to its tight orbit that makes it much closer to its star than Neptune is to the Sun by
a factor of 30 times.
At its discovery, it was the smallest exoplanet ever found orbiting a star and the first extrasolar
planet to have had its clouds mapped, which revealed a bright spot on the planet and moon-like
phases when orbiting its star.
This discovery provided scientists with evidence for theories they had only theorized about
before.
It was revealed that a bright spot exists on the planet and it was also observed that
it displays moon-like phases when orbiting its star.
11) Kepler 186f is an Earth-like planet since it is in the habitable zone that contains
light elements such as hydrogen and helium.
However, since no liquid water has been detected on its surface, it is likely that any water
present is frozen or concentrated in areas such as hot springs or deep lakes.
Additionally, Kepler 186f is a super-Earth with a mass of approximately 3.5 times that
of Earth and orbits its star at a distance of one third the one where liquid water is
stable.
Thus, detailed analysis with tools such as spectroscopes will help to understand its
atmosphere and composition.
10) Kepler-438B is a potentially habitable planet that orbits in a tidal lock with its
star.
It is located just outside the habitable zone, however its magnetic field increases its chances
of possibly sustaining life.
If it had an atmosphere, it would consist of carbon dioxide, nitrogen, water vapor,
and methane - all of which are essential components of life.
The planet's mass of 2.3 Earth masses gives it a gravity that is 30 times that of Earth,
making conditions on its surface relatively bearable.
It is somewhat older than other stars, and its close proximity to its star and low levels
of X-ray and extreme ultraviolet radiation make it a promising candidate for habitation.
9) Kepler 62f and Kepler-186f have some similarities, namely they both orbit in the habitable zone
and have long orbits.
However, Kepler 62f is much colder than Kepler-186f and is outside of its star's habitable zone,
making it unlikely to have liquid water on its surface.
Despite this, Kepler 62f's mass of 1.6 Earth masses would cause it to have a lower surface
gravity, potentially allowing liquid water on its surface.
If Kepler 62f has an atmosphere, it would most likely include carbon dioxide and other
volatiles like water vapor and methane, which are all necessary for life as ee know it.
Kepler 62f is also a super earth, with a mass of 3.5 times that of the Earth.
8) Kepler-296f is a Super Earth planet located just outside its star's habitable zone, resulting
in frequent flares from the star.
It is smaller than Uranus and Neptune, two of the Solar System's ice giants, but has
a high likelihood of having a large atmosphere.
The atmosphere of Kepler-296f is likely to consist of carbon dioxide and other volatiles
such as water vapor and methane, which are necessary for life as we know It.
Additionally, the length of a year on Kepler-296f is about 290 days, similar to that of Earth.
7) Kepler-22b is an exoplanet 600 light years away from its star, located in the habitable
zone, indicating that it has the potential to harbour liquid water on its surface.
It orbits in a relatively narrow path and is similar to Jupiter in terms of mass and
size.
However, its high surface gravity makes it less suitable for life.
It is twice the distance and time Earth takes to orbit the Sun.
6) In 2009, NASA's Kepler Telescope discovered Kepler 36B, a planet that is relatively small
in mass but otherwise similar to Earth in terms of its climate and rotational speed.
It orbits a star similar to the Sun, making it a part of the star's habitable zone with
the potential for liquid water on its surface.
Unfortunately, Kepler 36B has an erratic orbit that could eventually cause it to move out
of the habitable zone, making it uninhabitable and causing its atmosphere to mix with the
stellar wind.
On top of that, Kepler 36B has an orbital period of just 14 days, much less than the
Earth's 365 days.
5) Kepler 442 B has a mass and size comparable to Earth, making it a promising choice for
further research.
It orbits very close to where liquid water can remain stable and is located in the star's
habitable zone.
This suggests the exoplanet may have liquid water on its surface.
In addition, Kepler-442b is suspected to contain a thin atmosphere of methane and/or carbon
dioxide, two essential components for life as we know it.
4) Kepler-69b is a rocky planet that has a similar mass and size to that of the Earth
and orbits closely within the habitable zone of its star.
This suggests that liquid water may exist on its surface and that its atmosphere could
contain methane and carbon dioxide, both essential components for life as we know it.
Although it is not as Earth-like as some other exoplanets, Kepler-69b remains a promising
contender for habitability. 3) K22b, formerly known as TK7, is a small
asteroid with a mass below 445 Earth masses that orbits close to its star in a range between
the orbits of Mars and Earth.
It is located within the star's habitable zone, suggesting the potential for liquid
water on its surface.
Initially identified by the Kepler Telescope as a transiting planet, the asteroid was later
found to be K22b. 2) HD 40307 G is a potentially habitable exoplanet
located in our Stellar neighborhood, only 42 light-years away.
It has a similar mass and size to Earth and orbits squarely in its star's so-called habitable
zone.
This means that the atmospheric conditions could be similar to those on Earth, and that
it could potentially have liquid water on its surface.
Its tightly-orbiting star makes it a great candidate for further analysis to determine
if it has an atmosphere and surface water, putting it high up on the list of potentially
habitable exoplanets. 1) K225b is a promising exoplanet situated
only 147 light years from us and is situated inside the habitability zone of its star,
possessing similar mass and size to that of Earth.
Its particularly close orbit to its star, 3.5 days, make it an ideal candidate for further
evaluations to determine its atmosphere and the presence of liquid water.
All these factors put K225b at the top of the list of potentially inhabitable exoplanets.
--- The search for potentially habitable exoplanets
continues, providing a fascinating exploration for us to journey into the wonders of the
universe.
With each discovered planet, our understanding of the cosmos expands.
As we explore further into the depths of space, and continue to develop more advanced technology,
we can only hope to discover more and more exoplanets with life-sustaining conditions.
Until then, we can marvel at the discoveries that TESS and other all-sky surveys have led
to, and dream of the possibilities of life on other planets.
So what do you think?
Are these planets better than Earth?
Could we find life on them?
Or even better, could we live on them one day?
You've reached the end of this video, if you have a theory on your own, on whether there's
life outside of Earth, don't hesitate to let us know in the comments!
We are interested in what you think!
Thank you for watching!
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