as humanity is becoming more and more advanced we are also becoming more and more curious to
find out what is stored in the galaxy apart from us for the last 30 years we have been
discovering planets outside our solar system in hopes of finding alien life
a second home for humans or planets that can help us unlock the mysteries of the universe
and fortunately now we have artificial intelligence doing it for us welcome to
phenomenal let's find out how ai is helping us discover exciting exoplanets in the galaxy
since the dawn of humanity humans have looked up to the night sky and wondered what lies in
the space beyond the stars since that moment we've realized the earth is not the center of
the universe and we understand how star systems and galaxies work and we've been searching the
endless space as far as our site can reach in the universe our own galaxy the milky way has hundreds
of billions of stars and those billions of stars are harboring hundreds of billions of planets
so when we look up in the sky it's only natural to think about planets planets where we can
live or planets that are already teeming with life and perhaps super advanced civilizations
and what they may think about us since the end of the 1980s humans have been searching for planets
that are not our neighbors and live far away orbiting stars other than our sun the exoplanets
it all started with the launch and deployment of the hubble telescope in 1990 named after edwin
hubble who proved the existence of other galaxies in the universe in 1923 the hubble telescope made
huge strides in measuring the accurate distance between space bodies and determining how the
universe would have been in its early years but the first exoplanet or we should say exoplanets
were discovered by the polish astronomer alexander volkskin in 1992 breaking all the
theories and beliefs about how planets are formed and behave these rocky planets revolve around a
pulsar and not a star and in the last 30 years we have deployed more telescopes in space such
as kepler spitzer and tess by nasa most by csa and gaia and chiops by the european space agency which
has helped us find possibly 5 000 more exoplanets in our galaxy but how do they do that how can
these telescopes peer through vast and crowded space to discern objects way beyond our reach
well they actually have more than one trick to accomplish these astonishing discoveries
most planets are found via the transit method it is the same method that was used to find
the trappist-1 planets a solar system that is like a mini version of our solar system
with seven earth-like planets in fact the word trappist stands for the ground-based
transiting planets and planetesimal small telescope so how does the transit method work
a solar eclipse for example is a transit occurring as the moon passes between the sun and earth
exoplanet transits occur when a distant exoplanet passes between its star and earth
when a total solar eclipse takes place our sun's light goes from one hundred percent to
almost zero percent as seen from earth then back to one hundred percent as the eclipse ends but
when scientists observe distant stars in search of transiting exoplanets a star's light might
and most dim by only a few percent or fractions of a percent still assuming it happens regularly
as the planet orbited star that minute dip in a star's light can reveal an otherwise hidden planet
so the dip in a star's light is a handy tool for revealing exoplanets to use it astronomers
have had to develop very sensitive instruments that can quantify the light emitted by a star
that's why although astronomers looked for exoplanets for many years they didn't begin
to find them until the 1990s when we began deploying these powerful telescopes in space
some planets are found via the wobble method the second most used path to discovering exoplanet
is via doppler spectroscopy sometimes called the radial velocity method and commonly known as the
wobble method as of april 2016 582 exoplanets were discovered using this method that's about 30
percent of the total known planets at the time in all gravitationally bound systems involving stars
the objects in orbit in this case a star and its exoplanet move around a common center of
mass when an exoplanet's mass is significant in comparison to its star's mass there is the
potential for us to notice a wobble in the center of mass detectable via a shift in the
star's light frequencies this shift is essentially a doppler shift it is the same sort of effect that
makes the race car's engine sound room in high pitch as the car zooms toward you and
low pitch as the car races away likewise when viewed from earth the slight movement of a star
and its planet around a common center of gravity affects the star's normal light spectrum
if the star is moving towards the observer then its spectrum would appear slightly shifted towards
the blue if it is moving away it will be shifted towards the red the difference isn't very big but
modern instruments are sensitive enough to measure it so when astronomers measure cyclic changes in
the light spectrum of a star they may suspect a significant body that is a large exoplanet
is orbiting it other astronomers may then confirm its presence the wobble method is useful only for
finding very large exoplanets earth-like planets couldn't be detected in this manner because the
wobble caused by earth-like objects is too small to be measured by current instruments
also managed to find some planets via direct imaging direct imaging is fancy terminology for
taking a picture of the exoplanet it's the third most popular method of discovering exoplanets
but it is a very difficult and limiting method first of all the star system has to be relatively
close to earth next the exoplanets in that system must be far enough from the stars so
that astronomers can distinguish them from the star's glare also scientists must use a special
instrument called a coronagraph not at all related to the virus to block the light from the star
this reveals the dimmer light of any planet or planets that may be orbiting it
according to astronomer kate falette the number of exoplanets found via direct imaging varies
depending on one's definition of a planet but she did state that anywhere from 10 to
30 have been discovered in this way so not a total bust right
however if a planet is very tiny and absorbs all the light from its host star we need something
special to discern these extra dark cosmic objects einstein's general relativity yes science
so how do we use general relativity to find these planets objects in space curve space time and so
light traveling near them bend as a result this is analogous to optical refraction in some ways
if you put a pencil in a cup of water the pencil appears broken because the light is refracted by
the water although it wasn't proven until decades later the famous astronomer fritz zwicky said as
early as 1937 that the gravity of galaxy clusters should enable them to act as gravitational lenses
in contrast to galaxy clusters or even single galaxies stars and their planets are not very
massive they don't bend light very much that's why this method is called microlensing to use
microlensing for exoplanet discovery one star must pass in front of another more distant star
as seen from earth scientists may then be able to measure the light from the distant source
being bent by the passing system allowing them to differentiate between the intervening star
and its exoplanet this method works even if the exoplanet is very far away from its star
which is an advantage over the transit and wapple methods but
as you can imagine it's a difficult method to use only 19 planets have been found using this method
all the conventional methods we mentioned in this video have certain pros and cons
however few common downsides to these methods are that they are extensively time taking need manual
monitoring and the collective data collected by telescopes are plenty to sort through this is why
a research team at the university of warwick led by david armstrong has created an algorithm or in
simpler terms and artificial intelligence to sort through the copious amounts of observation data
researchers use nasa's transiting exoplanet survey satellite or test to study the data put it simply
a dip in the brightness indicates that something is passing by a star
it doesn't always have to be a planet but it helps narrow down the search this led to the research
team creating a machine learning algorithm that was applied to nasa's kepler mission
and was able to differentiate planets from other celestial objects the algorithm was a
big breakthrough as the ai was able to confirm as many as 50 planets the ai's efficiency has allowed
scientists to focus their resources and time on confirmed planets instead of wasting their
time trying to identify new ones with a longer method used till now this will also help them
rank planets that can have a similar atmosphere to the earth rather than saying which candidates
are more likely to be planets scientists can now say what the precise statistical likelihood is
where there is less than a one percent chance of a candidate being a false positive
it can be considered as a validated planet the algorithm is still in its early phase despite
the breakthrough however it will be further used on the ginormous amount of data collected from
projects like tess and esa's planned plato mission the warwick research team is still working on the
algorithm and once the ai is completed it will be much easier and quicker to find future potential
exoplanets and the more discoveries the a.i will find the more it will learn from them and the more
powerful it will become who knows maybe one day the ai will find the perfect home for humanity
after we leave earth to expand our horizons do you think it's possible and how soon will it happen
tell us in the comments and as always thanks for watching fact nominal