India's Moon Exploration Program

[Indx TechStyle]

Sep 19, 2019
Update on Chandrayaan – 2

• All Payloads of orbiter are powered.
• Initial trials for orbiter Payloads are completed successfully.
• Performance of all orbiter Payloads is satisfactory.
• Orbiter continues to perform scheduled science experiments to complete satisfaction.
• National level committee consisting of academicians and ISRO experts are analyzing the cause of communication loss with lander.

 

[here2where]

The vikram failure seems to have bought out the knives for Sivan. Former scientists say he is a better manager than visionary.

 

[vampyrbladez]

The vikram failure seems to have bought out the knives for Sivan. Former scientists say he is a better manager than visionary.

Must be Congressi chuttards! No one behaves like this wrt to a fellow scientist and the timing during UNGA is very suspicious!

Who needs enemies when your own countrymen behave like this!

 

[maniacguy]

Must be Congressi chuttards! No one behaves like this wrt to a fellow scientist and the timing during UNGA is very suspicious!

Who needs enemies when your own countrymen behave like this!

The internal 5th column should be dealt with iron fists. Human rights can take a hike.
These traitors should be extinguished into thin air leaving no trace.

 

[Anikastha]

WION #Exclusive | Pakistani first female astronaut and scientist @namirasalim lauds @isro for #Chandrayaan2. She says its a giant leap for South Asia

first female astronaut.....when the fuck did porks send man to space.....last time i checked these dumb cunt awam is yet to launch its own satellite....

 

[Akula]

first female astronaut.....when the fuck did porks send man to space.....last time i checked these dumb cunt awam is yet to launch its own satellite....

She is just a part of a group, which are going to space in Virgin Galatic Spaceship one as space tourists.

 

[Anikastha]

She is just a part of a group, which are going to space in Virgin Galatic Spaceship one as space tourists.

counting chickens b4 they hatch.....they have to pay for the ride right????
she aint selected like other astronaut....

 

[Akula]

counting chickens b4 they hatch.....they have to pay for the ride right????
she aint selected like other astronaut....

Yeah, they have to pay for a ride. From past 10 years I am hearing about Virgin Galatic going to space.

 

[Anikastha]

Yeah, they have to pay for a ride. From past 10 years I am hearing about Virgin Galatic going to space.

according to wiki first flight was to take place b/w 2009-2014.............

 

[Akula]

according to wiki first flight was to take place b/w 2009-2014.............

First prototype got crashed and pilot died in that incident.

 

[here2where]

Must be Congressi chuttards! No one behaves like this wrt to a fellow scientist and the timing during UNGA is very suspicious!

Who needs enemies when your own countrymen behave like this!

Not congress or other political parties but scientists and ISRO colleagues.

 

[Indx TechStyle]

Chandrayaan-2 orbiter performing very well, has begun experiments: Isro chief K Sivan

Working on plans for future moon mission: ISRO chief

 

[Indx TechStyle]

Oct 04, 2019
Chandrayaan2 - Images from the Orbiter High Resolution Camera

 

[Indx TechStyle]

Studying Earth’s extended magnetosphere (geotail) plasma around Moon

Our Sun emits a continuous outflowing stream of electrons and protons into the solar system, called the solar wind. The solar wind plasma which has charged particles embedded in the extended magnetic field of the Sun, moves at speeds of a few hundred km per second. It interacts with solar system bodies including Earth and its moon. Since the Earth has a global magnetic field, it obstructs the solar wind plasma and this interaction results in the formation of a magnetic envelope around Earth, called the magnetosphere.

The Earth’s magnetosphere is compressed into a region approximately three to four times the Earth radius (~22000 km above the surface) on the side facing the Sun, but is stretched into a long tail (geotail) on the opposite side that goes beyond the orbit of Moon. Approximately, once every 29 days, Moon traverses the geotail for about 6 days centered around full moon. Thus Chandrayaan-2 also crosses this geotail and its instruments can study properties of geotail at a few hundred thousand kilometers from Earth.

The CLASS instrument on Chandrayaan-2 is designed to detect direct signatures of elements present in the lunar soil. This is best observed when a solar flare on the Sun provides a rich source of x-rays to illuminate the lunar surface; secondary x-ray emission resulting from this can be detected by CLASS to directly detect the presence of key elements like Na, Ca, Al, Si, Ti and Fe.

While this kind of “flash photography” requires one to await an opportune time for Sun to be active, CLASS in its first few days of observation, could detect charged particles and its intensity variations during its first passage through the geotail during Sept.

The figure shows the change in intensity of particle events (believed to be mostly electrons), sometimes as much as 10 times the levels outside the geotail, indicating complex interplay with the magnetic field.

More detailed studies in future along with observations from other space missions, will enable a multi-point study, essential to unravel the “dance of electrons to the music of magnetic fields” around Moon.

 

[Indx TechStyle]

Chandrayaan-2's orbiter finds lunar crater named after German scientist, detects charged particles

 

[Indx TechStyle]

Oct 10, 2019
Solar flare observed by the Solar X-ray Monitor on Chandrayaan-2

Many violent phenomena continuously keep occurring on surface of the Sun and its atmosphere known as the corona. This solar activity follows an eleven-year cycle, which means, it goes through its 'solar maxima' and 'solar minima' once every eleven years. While the cumulative emission of solar X-rays emitted over a year varies with the solar cycle, these are often punctuated with extremely large x-ray intensity variations over very short periods, few minutes to hours. Such episodes are known as solar flares.

Chandrayaan-2 orbiter utilizes X-rays emitted by the Sun in a clever way to study elements on the lunar surface. Solar X-rays excite atoms of constituent elements on the lunar surface. These atoms when de-excited emit their characteristic X-rays (a fingerprint of each atom). By detecting these characteristic X-rays, it becomes possible to identify various major elements of the lunar surface. However, in order to determine their concentration, it is essential to have simultaneous knowledge of the incident solar X-ray spectrum.

The Chandrayaan-2 orbiter carries two instruments, Chandrayaan 2 Large Area Soft X-ray Spectrometer (CLASS) and Solar X-ray Monitor (XSM), to measure the lunar elemental composition using this technique. Here, the CLASS payload detects the characteristic lines from the lunar surface and the XSM payload simultaneously measures the solar X-ray spectrum.

Currently, the solar cycle is heading towards minima and the Sun has been extremely quiet for past few months. On 30th September 2019 00:00 UTC - 1st October 2019 23:59 UTC, a series of small flares were observed by XSM.

The figure shows the solar X-ray flux as measured by XSM (in blue) during this period, and for comparison, the flux measured by X-ray sensor on the Geostationary Operational Environmental Satellite (GOES-15) is also shown (in orange), which is considered the standard for solar X-ray intensity measurement.It shows that XSM is able to detect the intensity variations of the Sun much beyond the sensitivity limit of GOES. The gaps seen in GOES light curve around 09:00 UTC are due to instrumental artifacts. The GOES data was obtained from the National Center for Environmental Information of National Oceanic and Atmospheric Administration, USA.

Apart from the better sensitivity, XSM also measures the spectrum of solar X-ray in the energy range of 1 - 15 keV with highest energy resolution so far for any broadband solar X-ray spectrometer over intervals as short as 1 second.

Although this solar flare observed at present may not enable the study of the lunar surface composition due to the large angle between Sun, lunar surface and Chandrayaan-2 (close to 90 deg in this case against a desirable low value, close to zero), such XSM observations provide very useful data to understand various processes on the Sun.

 

[Indx TechStyle]

Oct 17, 2019
Chandrayaan-2 begins spectroscopic studies of lunar surface

Imaging Infrared Spectrometer (IIRS) on-board Chandrayaan-2 is designed to measure the reflected sunlight and emitted part of Moon light from the lunar surface in narrow and contiguous spectral channels (bands) ranging from ~800 – 5000 nanometer (0.8-5.0 micrometer (µm)). It uses a grating to split and disperse the reflected sunlight (and emitted component) into different spectral bands. The major objective of IIRS is to understand the origin and evolution of the Moon in a geologic context by mapping the lunar surface mineral and volatile composition using signatures in the reflected solar spectrum.

The first illuminated image of the lunar surface was acquired by IIRS. The image covers part of the lunar farside in the northern hemisphere. Few prominent craters are seen in the image (Sommerfield, Stebbins and Kirkwood).

Preliminary analysis suggests that IIRS could successfully measure the variations in the reflected solar radiation that bounces off the lunar surface from different kinds of surface types, namely, crater central peaks (e.g., Stebbins), crater floors (e.g., Stebbins and Sommerfield), very fresh reworked ejecta associated with small craterlets within the crater floor of a large crater (e.g., Sommerfield) and also the sun-illuminated inner rims of craters (e.g., Kirkwood). The variations in the spectral radiance are primarily due to the mineralogical/compositional variations that exist in the lunar surface and also due to the effect of space weathering. More detailed analysis that follows, is expected to yield important results on the heterogeneity of lunar surface composition.

 

[Indx TechStyle]

Oct 22, 2019
Initial imaging and observations by Chandrayaan-2 Dual-Frequency Synthetic Aperture Radar (DF-SAR)

Moon has been continuously bombarded by meteorites, asteroids and comets since its formation. This has resulted in the formation of innumerable impact craters that form the most distinct geographic features on its surface. Impact craters are approximately circular depressions on the surface of the moon, ranging from small, simple, bowl-shaped depressions to large, complex, multi-ringed impact basins. In contrast to volcanic craters, which result from explosion or internal collapse, impact craters typically have raised rims and floors that are lower in elevation than the surrounding terrain. The study of the nature, size, distribution and composition of impact craters and associated ejecta features reveal valuable information about the origin and evolution of craters. Weathering processes result in many of the crater physical features and ejecta material get covered by layers of regolith, making some of them undetectable using optical cameras. Synthetic Aperture Radar (SAR) is a powerful remote sensing instrument for studying planetary surfaces and subsurface due to the ability of the radar signal to penetrate the surface. It is also sensitive to the roughness, structure and composition of the surface material and the buried terrain.

Previous lunar-orbiting SAR systems such as the S-band hybrid-polarimetric SAR on ISRO’s Chandrayaan-1 and the S & X-band hybrid-polarimetric SAR on NASA’s LRO, provided valuable data on the scattering characterisation of ejecta materials of lunar impact craters. However, L & S band SAR on Chandraayan-2 is designed to produce greater details about the morphology and ejecta materials of impact craters due to its ability of imaging with higher resolution (2 - 75m slant range) and full-polarimetric modes in standalone as well as joint modes in S and L-band with wide range of incidence angle coverage (9.5° - 35°). In addition, the greater depth of penetration of L-band (3-5 meters) enables probing the buried terrain at greater depths. The L & S band SAR payload helps in unambiguously identifying and quantitatively estimating the lunar polar water-ice in permanently shadowed regions.

A convenient approach towards discerning the radar information is to prepare images using two derived parameters, ‘m’ the degree of polarization and ‘δ’ the relative phase between the transmit-receive polarized signals. These parameters are used to generate colour composite images with ‘even-bounce’, ‘volume or diffused’ and ‘odd-bounce’ scatterings of a pixel represented in red (R), green(G), and blue (B) image planes, respectively. The genesis of the scattering mechanism is as illustrated in Figure 1.

Figure 1: Conceptual diagram explaining different types of Radar scattering mechanisms on lunar surface and sub-surface

Figure 2 is one of the m- δ decomposition images from the first datasets acquired over lunar south polar regions in L-band high-resolution (2mslant-range resolution) hybrid polarimetric mode. It is important to note that the obtained resolution is one-order better than the earlier best by a lunar-radar. This image presents many interesting facts about the secondary craters of different ages and origins in the lunar south polar region. The yellowish tone around crater rims in the image shows ejecta fields. The distribution of ejecta fields, whether uniformly distributed in all directions or oriented towards a particular side of a crater, indicates the nature of the impact. The image shows craters of vertical impact and oblique impact on the top-right and bottom-right, respectively. Similarly, the roughness of the ejecta materials associated with the impact craters indicates the degree of weathering a crater has undergone. Three similar sized craters along a row on the bottom-right of the image show examples of young crater, moderately weathered crater and an old degraded crater. Many of the ejecta fields seen in the image are not visible in high-resolution optical image over the same region, indicating the ejecta fields are buried beneath regolith layers.

Figure 2

Chandrayaan-2 Orbiter’s DF-SAR has been operated in full-polarimetry mode- a gold standard in SAR polarimetry, and is the first-ever by any planetary SAR instrument. Figure 3 shows an L-band fully-polarimetric, 20m slant-range resolution image of Pitiscus-T crater. The image is a colour composite of different transmit-receive polarization responses of the imaged region.

Figure-3

 

[Chinmoy]

Oct 22, 2019
Initial imaging and observations by Chandrayaan-2 Dual-Frequency Synthetic Aperture Radar (DF-SAR)

Figure 1: Conceptual diagram explaining different types of Radar scattering mechanisms on lunar surface and sub-surface

Figure 2

Figure-3

I am just loving the vividness of these pictures.

Can't have enough. Feeling like a kid in candy store. :biggrin2:

 

[Indx TechStyle]

Oct 31, 2019
Detection of Argon-40 in the lunar exosphere

Planetary scientists prefer to call the thin gaseous envelope around the Moon as the ‘Lunar exosphere’ since it is so tenuous that the gas atoms very rarely collide with each other. While the Earth’s atmosphere near the mean sea level contains ~1019 atoms in a cubic centimetre of volume, the lunar exosphere contains ~ 104 to 106atoms in a cubic centimetre.

Argon-40 (40Ar), which is one of the isotopes of the noble gas Argon, is an important constituent of the lunar exosphere. It originates from the radioactive disintegration of Potassium-40 (40K), which has a half-life of ~1.2 X 109 years. The radioactive 40K nuclide, which is present deep below the lunar surface, disintegrates to 40Ar, which, in turn, diffuses through the intergranular space and makes way up to the lunar exosphere through seepages and faults.

Schematic of the origin and dynamics of 40Ar in lunar exosphere

The Chandra’s Atmospheric Composition Explorer-2 (CHACE-2) payload aboard the Chandrayaan-2 orbiter, is a neutral mass spectrometer-based payload which can detect constituents in the lunar neutral exosphere in the range of 1-300 amu (atomic mass unit). As part of its early operation, it has detected 40Ar in the lunar exosphere from an altitude of ~100 km, capturing the day-night variations of concentration. 40Ar being a condensable gas at the temperatures and pressures that prevail on the lunar surface, condenses during lunar night. After lunar dawn, the 40Ar starts getting released to the lunar exosphere (blue shaded region in figure).

Variation of Argon-40 observed during one orbit of Chandrayaan-2 during dayside and nightside of the Moon. The observed partial pressure has to be refined for the background and other effects to infer the density of lunar exospheric argon. The observations when Chandrayaan-2 was on the nightside is indicated by the black solid rectangle at the top of the panel and the two vertical dashed lines. Being in a polar orbit, Chandrayaan-2 enters the dayside of the Moon crossing the north pole, traverses through the dayside and enters the nightside after crossing the southpole.