Transcript
Search in video
Hello, friends!
Using Chandrayaan 3 India did something that
no country has done before.
A touchdown on the South Pole of the Moon.
The whole world celebrated this success.
But did you know that during Pragyan rover's mission,
it found Oxygen and Sulphur on the Moon?
Very few people have talked about
the new facts that were discovered during Chandrayaan 3's experiments.
But this discovery is really very interesting.
Let's know and understand this in today's video.
23rd August 2023 was the day
when Chandrayaan 3 landed successfully.
The next day, on 24th August,
Vikram Lander took the Pragyaan rover down a ramp
to start its mission.
ISRO was regularly updating us through Twitter.
In this video from 25th August, you can see how
Pragyan rover is moving away from Vikram Lander.
From 24th August to 4th September,
Vikram and Pragyan made observations on the moon for around 12 days.
After which they were put into sleep mode.
But it is expected that they will wake up again.
I will talk about this later,
but first, let's understand the observations from these 12 days.
It was on 27th August when
the CHaSTE instrument on Vikram Lander took its first readings.
CHaSTE stands for Chandra's Surface Thermophysical Experiment.
Its job was to measure the temperature of the topsoil of the moon.
To understand how much the temperature varies on Moon's South Pole.
The temperature was measured by a temperature probe attached on CHaSTE.
And there are 10 sensors on CHaSTE.
This temperature probe can go 10 cm below the surface of the moon.
The readings that it took there
were very shocking, in my opinion.
Look at this graph.
It was observed here that
by going 1 cm below the soil of the moon,
the temperature changes by 10° Celsius.
The temperature on the surface was almost 60° Celsius.
But by probing 8 cm into the soil,
the temperature reached -10° Celsius.
Such a big temperature difference
in just 8 cm.
This graph shows the temperature change at a depth of 0 to 80 mm.
This is the first profile made for the South Pole of the Moon.
The same day, ISRO published 2 photos of the Pragyan rover
when it was only 3 meters away from a big crater.
In this picture, you can see that
the diameter of this crater on Moon was around 4 meters.
Our scientists did not want Pragyan to fall into this crater.
So, they changed Pragyan's path.
Pragyan had to go back.
And you can see some interesting photos of this
where you can see the track of its wheels in the soil.
If we talk about the payloads on Pragyan,
on 28th August, LIBS i.e. Laser Induced Breakdown Spectroscopy instrument
confirmed the presence of sulphur on the south pole of the moon.
This was the first time that
this was confirmed on the ground on the south pole of the moon.
That's why it is called the first-ever in-situ measurement.
This LIBS instrument has been developed with ISRO
by Bangalore's Laboratory for Electro-Optics Systems.
Its job is to analyse the composition of the soil and rocks on the Moon.
And the way it works is also very interesting.
It uses high-energy laser pulses.
A laser is focused on the soil of the Moon,
whose temperature is very high.
This laser is targeted at a small area of the soil on the Moon.
The soil there, due to this high temperature,
gets converted into Plasma.
What is plasma?
You must have read about it in school.
The 4 states of matter.
Solid, liquid, gas
and the state after gas is plasma.
When you put gas through extremely high temperatures,
it gets converted into plasma
and the plasma emits light.
The special thing about this light that is emitted is that
different elements produce different wavelengths of light.
And our instrument here
measures the different wavelengths of light
and based on that, it can identify
the elements present in the soil of the moon.
This is where the name comes from.
Laser-Induced Breakdown.
We used a laser to break down
the stones or soil particles.
We converted them into plasma
and then we measured the wavelength emitted by them through spectroscopy.
This is why it is called
Laser-Induced Breakdown Spectroscopy.
Here, I want to say that I made a small mistake in the previous video on Chandrayaan 3.
The explanation that I gave right now,
there I told you that the RAMBHA instrument would do this,
but actually, it is not RAMBHA
but LIBS that does this.
RAMBHA will also measure plasma,
but not through laser-induced breakdown.
We will talk about RAMBHA later in the video.
But I apologise for the mistake.
Now look at this graph.
It shows the different wavelengths produced during spectroscopy.
We already know which wavelength of light
is produced by which element.
So, the wavelengths that are produced here in large quantities,
we can use them to conclude that
these elements are present in the soil of the moon.
There's Aluminium,
Fe i.e. Iron,
Ti-Titanium,
Sulphur,
Calcium,
and Cr-Cromium as well.
NASA's Project Scientist Noah Petro says that
the Apollo and Luna missions of Russia and America
had detected the presence of Sulphur on the Moon in the 1970s.
However, the discovery made by Chandrayaan
is a tremendous accomplishment.
Because these are in-situ findings.
It is the first experiment on the ground.
The technology used before this
was not so accurate.
For example, in 2011 NASA found that
there's a large quantity of Titanium on the moon.
But they used their Lunar Reconnaissance Orbiter for this.
An orbiter spacecraft that is orbiting or revolving around the moon.
The evidence wasn't found by landing an instrument on the moon.
Similarly, in 2009 a Japanese spacecraft also
detected Uranium on the Moon.
But the technology used in LIBS
is much more advanced.
And this is the first time that we made a definite discovery of Sulphur.
And apart from Sulphur, elements like Manganese, Silicon, and Oxygen
have also been confirmed.
You might be astonished at Oxygen being present on the Moon.
Friends, this Oxygen is actually present in the soil and rocks of the Moon.
This Oxygen is not present in the atmosphere in the form of O2 gas,
because there is no atmosphere on the moon.
In fact, in the rocks of the moon, oxygen atoms
exist in the form of bonds with different elements.
For example, silicate minerals
that are formed from silicon and oxygen atoms.
This is exciting news
because this oxygen can be extracted and used
for other use cases.
For example, if there happens to be a permanent base on the moon for astronauts
and oxygen is required there,
then oxygen can be extracted from the rocks of the moon.
Look at this article from 25th April of this year.
NASA successfully extracts oxygen from lunar soil simulant.
It means that NASA has already worked on the technology of extracting this oxygen.
And the quantity of oxygen is so high in the moon's soil
that it is said that the oxygen in the topsoil of the moon
is enough to sustain 8 billion people for 100,000 years.
Only with the oxygen in the top layer.
Now, there is another payload similar to LIBS on Pragyan,
Alpha Particle X-ray Spectrometer,
in short, APXS.
Where LIBS studied lunar rocks and lunar soil,
APXS is for the general surface of the moon.
But the way they both work is quite different.
LIBS uses laser pulses,
but APXS uses radioactive material.
Here, we should not forget that
the credit for making these precise instruments and advanced technology
goes to the engineers only.
Especially today
because today is September 15th
National Engineers' Day.
This day is dedicated to all those engineers
who work day and night
and X-rays on the surface sample.
Alpha particles are emitted during radioactive decay.
This means that in APXS
there is always a small radioactive source.
Radioactive material that it carries with it.
When these alpha particles and X-rays
interact with the atoms of the moon's surface,
the electrons of the materials present on the surface are released
and they start emitting X-rays.
The X-rays emitted from the surface
are then observed by the APXS detectors
to identify different elements.
This is how the name was coined.
Alpha Particle X-ray Spectrometer.
If you understand the process of how these instruments work,
then it will be easier to remember their names.
Now let's come to Vikram Lander.
On 31st August, ISRO released a report
on the functioning of RAMBHA.
RAMBHA is an instrument on Vikram
its full form is Radio Anatomy of
Moon-bound Hypersensitive Ionosphere and Atmosphere.
Like LIBS, its job is to analyse plasma.
But it doesn't produce plasma.
It doesn't emit a laser into the soil of the moon.
It measures the natural plasma that is already present on the moon.
This instrument is a 5 cm wide metallic spherical probe
which is placed on a pole at the height of 1 meter on Vikram's upper deck.
It was developed in the Kerala Space Physics Laboratory
at the Vikram Sarabhai Space Centre, Thiruvananthapuram.
In this photo published by ISRO
you can see the shadow of the RAMBHA instrument.
The pole that you can see in the shadow.
This is the instrument.
Even though there is no atmosphere on the moon,
but a minute amount of plasma naturally exists on the surface of the moon.
And RAMBHA detected this.
Approximately 5 to 30 million electrons per cubic meter of
plasma is present on the lunar surface.
It is so little that ISRO has defined it as being 'Relatively sparse'.
Electric current is used to measure it.
RAMBHA can measure minor small electric currents.
Pico-amperes.
Current is measured in amperes.
It measures current in pico-amperes.
10 raised to the power of minus 12.
The voltage is passed through the probe
and the current that returns is measured.
This identifies the densities of ion and electron in lunar plasma.
By measuring the return current.
But you will ask;
What does this mean?
Why does it matter to us?
This tells us that radio waves
can propagate easily on the moon
without much interruption.
Had there been more lunar plasma,
then transmission of radio waves would have been difficult.
So, with the help of these findings, we will be able to design such things
with which communication can be made easier.
Because for communication,
we use radio waves.
Then we come to the next instrument, ILSA.
ILSA's findings were also shared by ISRO on 31st August.
And the full form of this instrument is
Instrument for Lunar Seismic Activity.
Its name tells you that
it was made to study earthquakes on the moon.
ILSA is the first payload
to use Micro-Electro Mechanical Systems technology on the moon.
In short, MEMS
is a technology of microscoping devices.
That are made up of micro components.
They are so small that their size
is between 1 and 100 micrometers.
This technology is used in airbag sensors in vehicles,
in blood pressure sensors.
But if we talk about ILSA,
it was used to record vibrations.
When the Pragyan rover started moving on the moon's surface,
those vibrations were also recorded by ILSA.
You can see in this graph,
where the rover was moving,
its vibrations can seen on the graph like this.
But you will notice a line in the middle.
This line is from 26th August,
when a natural event occurred.
That is, at this point in time,
a natural quake hit the moon.
By studying these moonquakes,
we get a better understanding of the interior of the moon.
What is inside the moon?
What is the size of the crust?
What is the size of the mantle and core?
Apart from this, when humans go and permanently settle on the moon,
it will be very important then.
We should know about the scale of moonquakes.
How much will anything we make be able to sustain there?
After this, we come to 3rd September 2023
when ISRO conducted a hop experiment
with Vikram Lander.
The original point of landing,
named Shiv Shakti,
the lander was slightly shifted from that point.
Vikram's engines were fired again.
It went up about 40 cm
and landed again at a distance of 40-50 cm.
To conduct this experiment,
the ramp that was deployed to help Pragyan rover land
had to be folded back.
And the payloads of CHaSTE and ILSA were also taken inside.
You can see the photos of this hop experiment here.
The before and after photos.
You can see the difference between the before and after photos.
The lander moved a little.
The importance of this hop experiment is that
when we do human missions in the future,
we should know for sure that the lander can fly again.
To bring the humans back to Earth.
The next day, on 4th September, at around 8 AM,
both Pragyan and Vikram were put on sleep mode by ISRO.
This sleep mode was needed to prepare for the lunar night.
Former ISRO Chief Kiran Kumar claims that
they were put on sleep mode 2-3 days before the lunar night,
for better preparation.
So that the modules inside them
can properly and completely shut down
when the lunar day is over.
Pragyan's battery was fully charged before putting it to sleep mode.
And the location was chosen so that
when the sun rises again,
its solar panels are facing efficiently towards sunlight.
For now, the payloads of both Vikram and Pragyan have been shut down
but both their receivers have been left on.
As I told you in the previous video
earlier it was planned that this mission would last one lunar day only.
Which is equal to 14 Earth days.
Because it gets so cold at night that
it might not be able to survive.
But now ISRO has high hopes that
Pragyan and Vikram can wake up again
when the lunar day starts at the South Pole again.
This happened with China's lander and rover before.
When China sent its Chang'e-4 lander and its U-2 rover.
They were also put in sleep mode at night,
but when the sun rose again, they woke up too.
For Chandrayaan-3, the next morning will be on 22nd September.
And the whole country will be eager to see
whether they can wake up or not.
If they start working again,
it will be good news because
ISRO scientists will be able to run some more experiments.
But if this does not happen,
Pragyan will remain on the moon as India's Lunar Ambassador forever.
If you liked this video,
I have made a playlist of space-related videos.
You can click here to watch it.
There are many videos in it,
like the video on Black Holes
in which I explain the mystery of black holes.
You can click here to watch it.
Thank you very much!
No comments:
Post a Comment