KEPLER TELESCOPE DISCOVERS 26 NEW EXOPLANETS
PROPOSED TITLE: KEPLER SPACE TELESCOPE, THE EXOPLANET SEEKER.
Ever since we began exploring the universe and discovering the planets of our solar system,
the relentless quest to find life outside our world has become almost a necessity.
THE PLANETS OF THE SOLAR SYSTEM Starting with the scientific
revolution during the 16th century, astronomers understood that those
minor points in the sky that they called "wandering stars" were planets like ours.
And some people thought that perhaps, just as there were living beings on our planet,
it was likely that there were also on those planets.
ARE WE ALONE IN THE UNIVERSE? Already from 1877, the Italian astronomer
Giovanni Schiaparelli took advantage of the approach between the Earth and Mars to observe it
with a telescope and noticed that on the surface of Mars, there was a network of linear marks
that he named "Canals" because they resembled much to the Canals of water that were on Earth.
Later in 1908, the writer Percival Lowell would take Schiaparelli's observations and
wrote a book in which he suggested that those canals had probably been built by
an intelligent civilization to distribute water from the poles of Mars throughout the Planet.
At that time, there were no space telescopes,
so this idea of intelligent life on Mars was not unlikely; in fact, many scientists defended it.
Everything would become apparent until 1964, when the Jet Propulsion Laboratory would launch the
Mariner 3 and Mariner 4 space exploration probes to explore the surface of Mars.
Unfortunately, the first images the probes sent back to Earth showed that the surface
of Mars was a cold, dry, and lonely place, with no canals, no water, and no life.
From here, the story would repeat itself on all the planets;
whenever we sent a probe to explore the planets of the solar system,
the images did not show traces of any form of life.
Although those worlds were also planets like ours, in reality, they were very different;
the Earth was the only one of all the planets that housed water and living beings.
After exploring all the planets in the solar system, we realized that there were no Martians,
and we were utterly alone. NEW SOLAR SYSTEMS
But this never extinguished our spirit as explorers;
we keep looking at the natural satellites of planets like the 4 Galilean satellites of Jupiter,
Europa, Ganymede, Io, and Kalisto, as well as those of other gaseous planets.
From the sixteenth century, it was a consensus among all astronomers
that the Earth was not the center of the universe,
but rather, it was the Earth and the rest of the planets that revolved around the sun.
From this idea, it was known that the stars were very far away and that, probably, the sun
was one more star of the many in the universe,
only that it was so close that it looked much larger than the rest of the stars in comparison.
Astronomers thought that if the other stars are also like our sun,
it is highly likely that they also have planets orbiting around them,
and every star in the sky is a solar system like ours alone that is very far away.
However, at that time, there were no astronomical observatories that would be dedicated to looking
for planets in the stars, much fewer many telescopes that could carry out this titanic task.
We had to wait several centuries for this idea to become a fact, at the Florence conference in 1995
where the Swiss astronomers Michel Mayor and Didier Queloz announced with emotion that they
had discovered the first exoplanet in history using the Haute-Provence Observatory (France).
This would be called 51 Pegasi b since it orbited the star
51 Pegasi; From this discovery, more exoplanets quickly appeared. (6)
Finally, after hundreds of years of searching, humanity had a hint
that there were planets similar to ours beyond the solar system, in the stars.
The centuries-old search for other worlds like ours has been rejuvenated by the intense emotion
and widespread interest surrounding the discovery of hundreds of planets orbiting other stars.
Thanks to this, space programs emerged that, driven by the search for new worlds,
had the purpose of looking for planets where life could arise as on Earth.
KEPLER TELESCOPE One such program was the
Kepler Space Observatory, which had a mission to search for exoplanets similar in size to Earth.
The observatory was placed in orbit in 2009 and carried a series of instruments and tools
that allowed it to detect exoplanets in stars that were 300 light-years away.
Before the Kepler space telescope was put into orbit, only 337 exoplanets were known,
which had been discovered by telescopes on Earth, such as the Arecibo radio telescope
or the COROT COnvection ROtation et Transits planétaires telescope; that is, Convection,
Rotation and planetary Transits in English, which was a telescope very similar to Kepler but could
only detect giant planets, such as Jupiter or more prominent, due to the low resolution it had.
To detect extrasolar planets, there are several methods, but the most used,
due to its effectiveness, is the transit of planets.
A planetary transit occurs when a planet passes
before the orbiting star when we see it from Earth.
For example, in the case of the Earth, when Venus or Mercury pass right in front of the sun,
it is a "planetary transit" when a body like a moon passes in front
of the sun. It covers it completely; its denomination is that of "Eclipse."
When an exoplanet orbits its star, it may be the case that it is aligned
just with the line of sight of the Earth, with the "Ecliptic"
in that case, we can observe when the exoplanet passes right in front of its star.
If the Planet's orbit were not aligned with the line of sight of the Earth,
then it would orbit its star without passing in front of our vision.
In that case, we could never see it, since that the planets do not emit light,
we could only detect if the Planet is vast and is close enough to its star
to emit infrared radiation due to heat; otherwise, it will only be visible if we observe its transit.
When an exoplanet passes in front of its star, the total billing of the star decreases a little,
depending on the size of the Planet; this decrease can be 84 parts per
million for gaseous planets and 30 parts per million for rocky planets.
The Kepler space telescope was designed with a photometer capable of detecting decreases in the
brightness of stars of up to 20 parts per million; with that resolution, it could see planets the
size of the Earth, that is, worlds that had a high probability of having living beings.
FUNCTIONING The Kepler
telescope uses a 0.95-meter photometer and a 105-square-degree field of view (FOV); once
in space, it is placed in a heliocentric orbit near Earth with an orbital period of 372.5 days.
In this way, the telescope would be away from the interference of the moon and the Earth
while keeping one of its sides always pointing in the opposite direction to the sun.
In its orbit, the Kepler telescope would have the mission of studying more than 150,000 stars,
with the help of the photometer that allowed it to look at several stars at once.
Usually, the transits of exoplanets only last a fraction of a day; that is why if
we want to detect the transit of an exoplanet, all the stars must be continuously monitored.
That is, their brightness must be measured without interruptions.
For this to be possible, the field of view of the telescope must never be blocked by anything,
much less by sunlight at any time, which is why the telescope was placed in an orbit outside
the ecliptic, gradually moving away from the Earth and always turning its back on the sun.
In addition, the field of view had to have as many stars as possible at its fingertips without having
to move much from its place, so the regions of the constellation of Cygnus and Lyra were
selected for the search for exoplanets, since in these areas is where the highest concentration of
stars is located, because both constellations are pointing right towards the center of the galaxy.
Although kepler observations were delayed at first,
once all the observation instruments were calibrated giving results that exceeded
expectations. DISCOVERIES
On January 4, 2010, just one year after it entered service, the scientists controlling the Kepler
telescope announced the discovery of 5 exoplanets with sizes similar to Jupiter and Neptune.
Six months later, in June 2010, 706 candidates for extrasolar planets
would be announced. According to Dimitar Sasselov, a researcher on the project,
at least 40 of those candidates were Earth-sized planets.
A year later, in December 2011, the number of exoplanet candidates amounted to 2326.
Of those, 207 had a size very similar to the Earth. Still, only one had been confirmed;
this was the exoplanet (Kepler-22b) which not only had a size identical to the Earth but was also
within the habitable zone of its solar system. HABITABLE ZONE OR GOLDILOCKS ZONE
This is a region of the solar system where the temperature is ideal for a planet that
presents conditions similar to Earth's (Size, seismic activity, oxygen percentages, etc.)
to have water in a liquid state and, therefore, high probabilities of hosting life.
Kepler-22b was the first exoplanet found that met
this characteristic, but soon many more began to be found.
26 EXOPLANETS FOUND BY THE KEPLER TELESCOPE In 2012 NASA announced that the Kepler space
telescope found 11 planetary systems hosting 26 exoplanets, making an unprecedented
leap in the number of exoplanets discovered by a single telescope to date.
The discovery of the Kepler space telescope triplicates the number of stars known to have
more than one Planet transiting or passing in front of their host star; in other words,
the number of stars that have planets around them is much more significant than we had imagined.
That same year, following the discovery of the Kepler telescope, an international team
of astronomers performed the calculations to estimate the number of stars with planets that
we could find and informed the scientific community that each star of our galaxy host
"at least 1.6 planets", suggesting that there may be more than 160 billion planets in the Milky Way,
of which at least 25% are similar in size to Earth.
This discovery marked our way of seeing the universe;
it was no longer just an idea but a fact that in our galaxy,
there were hundreds of millions of worlds like ours waiting to be discovered.
While the Kepler telescope was active, it managed to verify the
existence of many more earth-sized planets; among the most famous are:
Kepler-20e and Kepler-20f: These are two exoplanets orbiting a Sun-like star
called Kepler-20; the first two exoplanets discovered were equal in size to Earth.
Kepler-9d: This was the second exoplanet slightly larger than
Earth's discovered around a sun-like star. Kepler-69c: Exoplanet orbiting within the
habitable zone, potentially high to host living things.
Kepler-62 Star System: A star with five planets orbiting around it with a size similar to Earth,
analyzes indicate that at least 2 of those planets are in the habitable zone
and are potentially habitable.
Kepler-16b: The first known exoplanet to orbit a binary star.
MISSION OVERVIEW K2 The Kepler space telescope
mission was set to last 3.5 years. In December 2012, when it was about to approach that date,
NASA extended the mission until 2016. However, a problem occurred.
For the proper functioning of the ship that transports the Kepler telescope, at least three of
the four gyroscopes used to orient the ship must remain in good condition, unfortunately. In early
2013, the first of them failed irremediably, and on May 15, the second of them died.
In an attempt to continue operating the telescope, NASA launched a new mission for Kepler called K2.
They sought to take advantage of the last two gyroscopes that remained in combination
with hydrazine fuel to move the Kepler telescope.
In this way, the telescope continued to operate until finally, on November 15,
2018, NASA declared that the third gyroscope had been lost irretrievably, ending the mission.
During its period of operation, the Kepler space telescope managed to verify the existence of 2740
exoplanet candidates, and so far, 114 planets have been confirmed in 69 different star systems.
Thanks to the Kepler telescope, we could see what our eyes could not,
but that we had always dreamed of,
we managed to confirm the existence of hundreds of worlds like ours out there, just waiting for us
to visit them and prove once and try at once for all if we are alone or not, in the vast universe.