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n our solar system,
about one and a half hundred small and large satellites of different sizes have
been discovered. Everyone has satellites except Mercury and Venus. The last
planet at the farthest end of this family is the ice giant Neptune and the
largest satellite of that Neptune is Triton. Today we will try to know it by
entering the astonishing world of this satellite.
Triton
is the largest satellite of Neptune, the farthest planet in our solar system. But
the most surprising fact is that Triton has not been with Neptune since its
birth. Outside of our original solar system, millions of meteors of various
sizes are orbiting the sun. The region with these meteors is called the Kuiper
Belt. During the formation of the solar family, this region was formed and it
consisted of isolated and destroyed parts of different planets. Triton was one
of their members. Under the influence of Neptune's intense gravitational force,
Triton dropped out of the Kuiper belt and turned into a satellite of Neptune.
This sudden arrival of Triton made some radical changes in Neptune's own
satellite system with some abnormalities, such as any of Neptune’s satellites
may have given birth to many tiny structures, hit by a meteorite that came
along with Triton or the satellites may have been orbiting Neptune in its new
orbit.
Neptune
The
first discovery of this satellite was made on October 10, 1846. It was
discovered by the English astronomer William Lassel. This was the first
satellite of Neptune, discovered after discovery of Neptune which was
discovered by Johann Galle on September 23, 1846, just 17 days before this
incident. This satellite has not been named for a long time since its
discovery. However, in 1880, French astronomer Camille Flammarion named the
newly discovered satellite Triton after the son of the Greek sea god Poseidon
in his book Astronomie Populaire. This name was later universally recognized.
With
a diameter of 2,710 kilometre, it is one of the most geologically active
satellites in the solar system and is a retrograde satellite that is, a planet
or satellite usually rotates in the opposite direction to Triton. Triton is the
seventh largest satellite in terms of size in our solar system. Its size is
larger than the dwarf planets Pluto and Eris. Triton orbits its planet 156
degree and maintains an average distance of 3,54,760 kilometre from Neptune.
This distance is slightly less than the average distance between the earth and
the moon. This satellite is bound in synchronous rotation with its planet. That
means, one side of Triton is always bound to Neptune. As a result, Triton's
rotation speed and annual speed are almost equal. Triton takes 5.88 days to
orbit its axis once which is approximately equal to the time it takes to orbit
Neptune once. As a result, duration of Triton's every season is equal to
duration of Neptune's every season. Each season of Triton has a lifespan of
about 41 years, which is equal to the time, taken by Neptune to cross
one-fourth of the total distance of its orbit. Triton's orbit is completely
circular, with an average orbital speed of 4.39 kilometre per second. Triton
has a very small mass, so its gravitational force is weak. Due to this, the
escape velocity of this satellite is very low to get out of the effect of
gravitational force. Its value is 1.46 kilometre per second or 5,256 kilometre per hour.
As
mentioned earlier, Triton represents those satellites which are still
geologically active. Its surface is still changing. The core of Triton is made
up of earth-like rocks and metals. Two-third of its total mass is concentrated
in the center. Like Pluto, Triton's crust is made up of a transparent ice layer
of nitrogen and it is about 55 percent of total mass of crust-material. The
rest of the crust contains water ice. The existence of carbon dioxide and
methane in solid state has also been found on the surface of Triton. The
surface of it is flat in nature. Its maximum elevation is only 1000 meter or 1 kilometre. The number of craters on the surface of Triton is very few. These
craters are usually called impact crater which are formed when they collide
with a cosmic object. Only 179 trenches have been found across Triton. The
Voyager II spacecraft has detected craters in only 3 percent area of the total
surface area. The largest crater ever found is called the Mazomba Crater. The
diameter of this crater is 27 km.
Where
the moon reflects only 12 percent of the sun's light, Triton reflects 80 to 95
percent of the sun's light. Triton's climate is extremely cold due to the large
distance from the sun and the large amount of light coming in to be reflected
in space. Its average temperature is -237.60 Celsius. Due to the
extreme cold, various gases are present in extremely dense condition here. It
has dense nitrogen clouds in its atmosphere which reach a maximum height of 3 kilometre from the ground. Nitrogen evaporates in the summer of Triton, just as
water evaporates on our planet in summer. In addition to the presence of
nitrogen, small amounts of carbon dioxide and methane have also been found in
its atmosphere. When the sun's ultraviolet rays come in contact with Triton's
atmosphere, the effect of that ray is to convert methane to Tholins, which
makes Triton look red. Its atmospheric troposphere is about 8 kilometre and the
thermosphere is about 950 kilometre wide.
Like our Earth, Triton
also has volcanoes. However, instead of heated lava, cool liquid nitrogen and
methane are emitted. This type of volcano is called a cryo-volcano. The
eruptions from all these volcanoes reach a height of about 8 kilometre.
Till
date, only one spacecraft has observed Triton. The name of the spacecraft is
Voyager II. On August 25, 1989, Voyager II flew 40,000 kilometre from Triton.
In 1954, Dutch astronomer Gerard Kuiper attempted to measure the diameter of
Triton and succeeded. Voyager II made this calculation more accurate and
precise. Voyager II has been able to map 40 percent of Triton. (For more
information on the Voyager mission see 'Voyager, The Oldest Surviving Space
Mission'. The link of the article is: https://spacejagat.blogspot.com/2020/02/voyeger.html)
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| Voyager Spacecraft |
One
of the strangest facts we have learned is that from 1989 to 1998, observations
showed that the average temperature of Triton's atmosphere increased by about 5
percent, and that it is still rising.
Our
knowledge of Triton is very limited. There are many questions that we do not
know the answers and we are still trying to solve those mysterious questions.
Here are some of the unsolved mysteries:
1.
What
is the reason for the increase in the average temperature of Triton?
2.
Is
there any microscopic organism suitable for the weather of this satellite for
which the average temperature of the satellite may be increasing as a result of
the greenhouse effect?
3.
How
do the different seasons occur in Triton?
4.
How
is the reciprocal rotation of Triton established after coming from the Kuiper
belt?
5.
What
causes Triton to have an almost flat surface?
6.
Why
is the number of craters, created due to result of the cosmic collision at
Triton, so low?
7.
Is
there any similarity in the history of Triton with Pluto? Etc.
Many
more such questions have arisen in the minds of scientists, the answers to
which can only be known by deep observation and research of Triton. At the end
of 2019, NASA announced the Trident Mission to collect information about
distant planets and satellites under the Discovery Project. According to them,
the Trident campaign will start on October 25, 2025. If for some reason, the
mission does not start then the campaign can be started till 2026. Then, using
the gravitational force of different planets, the spacecraft will move faster,
focusing on its farthest target. It is estimated that it will take 12 to 13
years for Trident to reach Neptune's largest satellite Triton. Trident will be
closest to Triton on June 26, 2038 during which the distance from Trident to
Triton will be only 500 kilometre, which is a good time to send a spacecraft to
Triton because at that time Triton will be in summer and in summer the
concentration of different gases in Triton will be a little less so we will get
some idea of its actual surface and it will be possible to draw maps of the
remaining area of that satellite.
Proposed Trident Spacecraft
But
not just drawing maps, perhaps the explanation of many more unanswered questions
will be possible as a result of future expeditions and the veil of mystery will
slowly lift. However, looking at the nature of Triton's motion, scientists have
realized that Triton is moving closer to Neptune little by little over time,
and they speculate that Triton may no longer exist in the future. After about
360 crore years, Neptune's atmosphere will collide with Triton, and Triton will
break up into Neptune's ring. As we see Saturn now, in the future Neptune may
look like Saturn.
But let us see what happens in the future for the time being. Instead, we take this opportunity in trying to rediscover Triton and understand the reality of science, thereby unveiling the mysterious darkness of our solar system as well as the universe.
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| THE TRITON |
