this file contains a deep study about the exoplanets, which is located outside the solar system

1. S.AJAY ADITHYA
10-D
KRM PUBLIC SCHOOL
EXOPLANETS
31st October 2020
OVERVIEW
❖ AN EXOPLANET OR EXTRASOLAR PLANET IS A PLANET WHICH EXIST OUT OF
OUR SOLAR SYSTEM,
❖ THE FIRST POSSIBLE EVIDENCE WAS NOTED 1917, AND AGAIN IT WAS
DETECTED AS A PLANET IN 1992.
❖ THIS IS A VAST SUBJECT WHICH MAY TAE MANY CENTURIES TO COMPLETE
THE STUDY AND ALSO TO DISCOVER AN EXOPLANET, WHICH IS ALREADY
FOUND BUT NO PROPER EVIDENCE TO CONCLUDE THE PLANET DO EXIST IN
THE REAL LIFE IN THE GALAXY, IT IS NEARLY TREATED OR CONSIDERED AS A
HYPOTHETICAL STUDY AND ALSO MANY PEOPLE ARE VERY WELL
INTERESTED IN HEARING THISCONCEPT BUT THERE IS NO PROPER
KNOWLEDGE FOUND IN THE PEOPLE WHO NEED TO LEARN THIS AND THEY
GIVE UP EASILY OR DO NOT LEARN TILL THE END.
GOALS
1. TO CONCLUDE THAT THE PLANET FOUND IS HABITABLE AND MOST IMPORTANTLY
TO FIND ANY LIVING ORGANISMSARE RUNNING THEIR LIFE OVER THERE AND ALSO
TRY TO COMMUNICATE THEM.
2. TO KNOW MORE ABOUT THEIR TECHNOLOGY AND THE WAR TECHNOLOGY, ARE THE
LIVING PEACEFULLY OVER THERE OR THEY ARE TRYING TO INVADE US.
SPECIFICATIONS
TO BE MORE SPECIFIC IT IS VERY TOUGH TO BE SUCCESSFUL IN THISCONCEPT, THE
EXOPLANETS WHATEVER WE SEARCH ARE MANY LIGHT YEARS AHEAD!!
EARTH AS AN EXOPLANET
EARTH IS A PLANET WHICH IS SITUATED IN THE SOLAR SYSTEM, WHICH HAS MANY
LIVING

2. BEINGS BUT HUMANS ARE THE CREATURES WHO ALL ARE EAGERLY RESEARCHING
ABOUT
THE OUTSIDE WORLD. AND WEAS A HUMAN WE HAVE FOUND MANY EXOPLANETS AS
WELL AS MORE ALIENATED ACTIVITIESIN THE SPACE BUT THE THINGIS WE DON’T HAVE
PROPER EVIDENCE TO PROVE THAT THEREIS ANOTHER CREATURES LIVING OUT OF
EARTH
EVEN THOUGH SOME PEOPLE SAY THAT EXOPLANETSEXIST IN REAL SO THEREWAS A
QUESTION ARRIVED IN MY MIND THAT THE CREATURES LIVINGIN A HABITABLE
EXOPLANETS MAY CONSIDER US ALSO A HABITABLE EXOPLANET AFTER A LONG
RESEARCH
WHICH IS THE TOUGHEST THING IN FINDING A EXOPLANETS. IF THEY HAVE A
SUFFICIENT
SPACE TECHNOLOGY THY CAN EVEN INVADE US EASILY BECAUSE THE WAR
TECHNOLOGY
DOES NOT TOUCHE THE PEAK IN FACT WE ARE 0 LEVEL IN SPACE TECHNOLOGY NOW
ONLY
STARTED TO DISCOVER THE THINGS IN OUR OWN SOLAR SYSTEMAND THUS IT TAKES
MINIMAL OF CENTURY TO REACH THE PEAK UNTIL THEN WE MUST BE CAREFUL IN THIS
RESEARCH IT DOES NOT MEAN THAT WE MUST RUN THAT RESEARCH IN A POSITIVE WAY.
WHAT DO MANY SPACE ORGANISATION SAY??
The planet-hunting space telescope was still getting its bearings, just a
few months after launch, when the floodgates burst open.
As NASA’s Kepler Space Telescope science team was wrapping up a 10-
day trial run, they saw something that bordered on the unbelievable: the

3. telescope's first detection of a rocky, Earth-sized world outside our solar
system.
The sun and our solar system in relation to the Milky Way
galaxy. The white circle indicates the area where the
majority of exoplanets have been found with current
telescopes. Credit: NASA/JPL-Caltech/T. Pyle

4. The planet, a hot, heavy world dubbed Kepler-10b, would be among the
early nuggets in a coming gold rush of exoplanet discovery—taking us
from a handful of planets confirmed to be in orbit around other stars to
thousands today, all in the space of two decades. Thousands more
candidate planets found by Kepler await confirmation.
“In that trial run we saw, already, the signal of what could be a small
planet orbiting a star about 540 light years away,” Natalie Batalha, an
astrophysicist and member of the Kepler team, told a public radio host
about the discovery, announced in 2011. “This was our first indication—
‘Oh my god! We’re going to find lots of these things. We’re going to find
lots of Earth-size planets.’”
Since the first confirmation of an exoplanet orbiting a sun-like star in
1995, and with only a few, narrow slices of our Milky Way galaxy so far
surveyed, we’ve already struck many rich veins. A recent statistical
estimate places, on average, at least one planet around every star in the
galaxy. That means there's something on the order of a trillion planets in
our galaxy alone, many of them in Earth’s size range.
“Right now we know, for the first time, that small planets are very
common,” said Sara Seager, a professor at the Massachusetts Institute of

5. Technology and an exoplanet research pioneer. “It’s phenomenal. We
had no way to know that before Kepler. We’ll just say, colloquially:
They’re everywhere.”
Hot Jupiters and wobbling suns
The planet discovered in 1995 was a hot, star-hugging gas giant believed
to be about half the size of Jupiter. It tugged so hard on its parent star as
it raced around in a four-day orbit that the star’s wobbling was obvious to
earthly telescopes—once astronomers knew what to look for.
51 Pegasi b, also called "Dimidium," was the first exoplanet discovered orbiting a star like our
sun. This groundbreaking find in 1995 confirmed planets like Earth could exist elsewhere in the
universe.

6. Finding this fast-moving giant, known as 51 Pegasi b, kicked off what
might be called the “classical” period of planet hunting. The early
technique of tracking wobbling stars revealed one planet after another,
many of them large “hot Jupiters” with tight, blistering orbits.
The wobble method measures changes in a star’s “radial velocity.” The
wavelengths of starlight are alternately squeezed and stretched as a star
moves slightly closer, then slightly farther away from us. Those gyrations
are caused by gravitational tugs, this way and that, from orbiting planets.
The European team of Michel Mayor and Didier Queloz announced their
discovery of 51 Peg using this method in 1995, and the race was on to
find others.
The others came—first by the dozens, then by the hundreds.

7. Swiss astronomers Didier Queloz and Michel Mayor in
front of La Silla Observatory in Chile. The pair discovered
51 Pegasi b in 1995, the first planet found orbiting a star
like our sun. Credit: L. Weinstein/Ciel et Espace Photos
After confirming the existence of 51 Peg, a science team led by Paul
Butler and Geoff Marcy, then of San Francisco State University, took a
second look at data from their own radial velocity observations. They and
the rest of the astronomical community hadn’t anticipated large planets
orbiting so closely and rapidly around their parent stars. Sure enough,
big, star-hugging planets began popping out of their data.

8. They announced two somewhat more plausible exoplanets, 70 Virginis
and 47 Ursae Majoris, in 1996. The first had a 116-day orbit, the second
an orbit of 2.5 years, helping overcome skepticism among their fellow
astronomers; these distant solar systems looked a lot more like ours.
The Butler and Marcy team went on to discover at least 70 of the first 100
exoplanets in the decade that followed, attaining celebrity status. Scores
of other ground-based research projects also joined the hunt, sending the
tally of known exoplanets into the low hundreds.
Then a new space telescope, and a new planet-hunting method, stole the
show.
Staring into space
Enter NASA’s Kepler Space Telescope, launched in 2009 to inaugurate
what we could call the “modern” era of planet hunting. Kepler settled into
an Earth-trailing orbit, then fixed its gaze on a small patch of sky. It stared
at that patch for four years.
Within that small patch were some 150,000 stars. Kepler was waiting to
catch tiny dips in the amount of light coming from individual stars, caused
by planets crossing in front of them. The result: more than 2,000

9. confirmed exoplanets were sifted from the data, the bulk of the more than
3,300 confirmed so far, with more than 2,400 planetary candidates as
scientists continue to mine Kepler’s observations.
The Kepler mission faced its own skeptical audience in the 1990s. Four
times, NASA rejected the designs proposed by William Borucki of the
NASA Ames Research Center in Moffet Field, California. Borucki, now
retired, finally won approval in 2001.
His idea was proven right; Kepler’s four years of data are still revealing
new planets. But failure of two reaction wheels on the spacecraft ended
its primary mission in 2013.
From the left to right, the Spitzer, Kepler, and Hubble space telescopes have discovered over
1,000 planets outside our solar system. Credit: JPL-Caltech/R. Hurt (SSC); NASA Ames/ W.
Stenzel; ESA
Still, it’s hard to keep a good spacecraft down. The Kepler science team
devised a clever fix: using the pressure of sunlight to stabilize one axis of
the telescope. The instrument was rechristened "K2" and continues to
discover planets, though at shorter observation times than its original
four-year stare.

10. Other instruments, on the ground and in space, continue to round out the
tally of exoplanets bagged so far. The European CoRoT satellite
preceded Kepler, and also used the transit method to find numerous
planets during its functional period from 2006 to 2012.
The Hubble Space Telescope not only has discovered a variety of
transiting exoplanets, but has characterized the atmospheres of some of
them. As a planet makes its transit across the face of its star, a sliver of
starlight shines through the planet’s atmosphere. Gases and chemicals in
the atmosphere absorb different wavelengths of the light as it passes
through. By looking for these missing slices of the star’s light spectrum,
scientists can tell which constituents are present in that alien atmosphere.
Another skywatcher, NASA’s Spitzer Space Telescope, observes
transiting exoplanets in infrared wavelengths, and has helped to chart and
characterize many, including puzzling out details of planetary
atmospheres.
Spitzer often works in conjunction with ground-based telescopes,
including OGLE’s Warsaw Telescope at the Las Campanas Observatory
in Chile. In 2015, a collaboration between Spitzer and Italy’s 3.6 meter
Galileo National Telescope in the Canary Islands revealed the closest

11. known rocky planet: HD 219134b, only 21 light-years away from Earth.
Disappointingly, however, the planet orbits its star too closely to make it
suitable for life.
All but a handful of the thousands of exoplanets observed so far have
been detected via indirect methods, such as watching for transits or
measuring star wobbles. We’ve only just begun to enter a new era of
planet hunting: direct imaging.
ARE THEY HABITABLE??
Discovering thousands of planets beyond our solar system counts
as a “eureka” moment in human exploration. But the biggest payoff
is yet to come: capturing evidence of a distant world hospitable to
life.

12. To find another planet like Earth, astronomers are focusing on the 'habitable zone' around
stars--where it's not too hot and not too cold for liquid water to exist on the surface.
We begin the search on familiar ground. On this planet, currently
our sole example of a life-bearing world, the need for water is non-
negotiable. So astronomers search the cosmos for similar
environments. Around almost every “normal” star, including our
sun, we can draw a band of potential habitability: the right distance
and temperature for liquid water to exist. The key, of course, is a
planetary surface where the water could pool. Both stars and

13. planets come in many types and sizes, and the interplay of these
factors determines the extent and influence of this “habitable zone.”
A giant, hot-burning star’s habitable zone would be found at a much
greater distance than that of a smaller, cooler stellar dwarf. And if
we stick with the plan—hunting first for what we know—then small,
rocky worlds are our best bet for finding evidence of life as we know
it (we’ll talk about “life as we don’t know it” in the next section).
So the ideal candidate is an Earth-sized, rocky world nestled
comfortably within its star’s habitable zone—though scientists’
understanding of what makes up a habitable zone continues to
evolve.
Wishing upon the right kind of star
That’s not the end of the story. While the size and composition of
both planets and stars are critical to habitability, so is time. Big
bright stars burn out far more quickly than their more modest
counterparts. The brightest burn for only a few million years, then
flame out; meanwhile, our sun has been shining steadily for 4.5
billion years, with about another 5 billion years to go. At that point it

14. will swell to many times its previous size to possibly engulf Earth
and the rest of the inner planets, though any lingering Earth life
would long since have burned to a crisp.
Artist's concept of a blue supergiant star.
The first microscopic life forms are thought to have emerged about
a billion years after Earth’s formation from the dust, globs and
chunks of material that made up the infant sun’s protoplanetary
disk. They might have emerged much sooner. But it took roughly

15. another 3 billion years for multi-celled, macroscopic creatures to
begin making their mark on the fossil record.
A few hundred million years could be enough time to produce
microbial life, but might be far too short a time frame for large
animals, especially the kind that begin talking to each other and
building radio telescopes. Scratch big, hot stars off our list of likely
candidates.
On the other hand, long-lived dwarf stars might be great places to
look—even those with habitable zones so close in that rocky worlds
within them would be tidally locked, constantly presenting only one
face to the star as the moon does to Earth. Scientists once thought
such worlds would be cooked on one side and frozen on the other,
but further modeling and observations suggest that planet-girdling
winds could even things out, providing some of these worlds with
temperate climates.
The safest bet might be sun-like stars, with planets of comparable
size and comparable orbits to Earth’s.
A growing handful of habitable worlds

16. So how is the search going? In just over 20 years of exploration,
ground and space-based observations have turned up more than
3,200 confirmed exoplanets in the few slices of our galaxy we’ve
been able to search. Add unconfirmed planetary candidates and the
number jumps to more than 5,600.
Many of the planets found so far are gas or ice giants, with little
chance of a solid surface harboring a warm little pond. But we’ve
also found some rocky worlds in Earth’s size-range. Even with the
expected advances in observing technology in years to come, we’re
unlikely to know the precise nature of any life we might detect, be
they crusts of algae or loping, six-legged giraffes. Still, among those
rocky, Earth-like worlds, we could catch tantalizing glimpses of the
right conditions for life.
Conclusion
Hence we can conclude that the species which we are aiming can even
aim us…..
THANK YOU

17. SOURCES:
NASA’S EXOPLANET BOOKS- https://exoplanets.nasa.gov/
NASA’S RESEARCH ON EXOPLANETS -
https://exoplanets.nasa.gov/what-is-an-exoplanet/about-exoplanets/
PEOPLE INVOLVED IN THE RESEARCH-
https://exoplanets.nasa.gov/what-is-an-
exoplanet/people/?page=0&per_page=40&order=first_name+asc
search=&external_api_url=https%3A%2F%2Fsolarsystem.nasa.gov%2Fapi
%2Fv1%2Fpeople%2F&external_asset_url=https%3A%2F%2Fsolarsystem.
nasa.gov%2F&category=213&spa=true