I am pretty sure that ISRO had created a back up for failure of the lander to have direct commmunication with the rover. If they did not, then they are fools.
Like all State-run agencies, ISRO too suffers from severe management problems. PR is beyond their understanding.
We should soon find some car mechanic who can tell us in unequivocal terms that the rover is a write off and cannot be repaired. Then we can auction the rover to the car mechanic to salvage it for parts.
Scientists reveal ‘unambiguous presence of water ice’ at permanently shadowed regions of Moon
One of the eight payloads of India’s second Moon mission, Chandrayaan-2, developed at Space Applications Centre (SAC) at Ahmedabad, has detected an unambiguous presence of water ice at the permanently shadowed regions of the Moon, revealed scientists of the Indian Space Research Organisation (ISRO) on Tuesday, the second day of a two-day lunar science workshop.Permanently shadowed regions (PSR) have largely remained inaccessible as no sunlight reaches these regions, making it difficult to get images.
The Dual Frequency Synthetic Aperture Radar (DFSAR), one of the eight payloads on board Chandrayaan-2, is the only full polarimetric radar sent on a planetary mission in the world so far and its capability to combine radar images from two wavelengths, allows it to differentiate surface roughness properties from water ice properties.
Earlier studies using hybrid-polarimetric SAR data led to ambiguous detection of water ice regions as it had similar sensitivity to surface roughness and water ice. However, full polarimetric DFSAR, which uses measurements of electrical properties of materials, can decouple the effect of water ice and surface roughness, “leading to encouraging results on unambiguous detection of water ice in some PSRs”, as stated in the public documents released by ISRO chairperson K Sivan on Monday.
Potential patches of “dirty ice” within the Cabeaus crater on the lunar south pole, were also detected by the radar instrument. Patchy dirty ice involves ice crystals mixed with the lunar regolith, unlike continuous sheets of ice. Regolith is the top surface of the moon extending upto three to four metres, consisting of loose deposits.
The ability to combine polarimetric radar images from two wavelengths has also brought forth subsurface features and the polarimetric data helps in identifying the distribution of impact melts.
“This is very very essential to get information on what kind of impact cratering took place and how the impact melts distributed around the craters,” said Anup Das of Ahmedabad’s SAC and part of the DFSAR science team, during his presentation.
“One benefit (of DFSAR) is, we are seeing better resolution so we are seeing more number of smaller craters and scattering mechanism is more prominent here… this data gets finer details of smaller craters compared to Mini-RF (miniature radio frequency on the lunar reconnaissance orbiter launched by NASA in 2009),” added Das.
Freshness of a crater indicates that it has not been exposed enough to space weathering and in the polar regions of the moon, the findings can be expanded to further estimate the age and impact processes that the craters or boulders or other subsurface structures underwent over the years.
The discussions also promised a better imaging of the PSRs by combining data and image results from orbiter high resolution camera (OHRC), one of the payloads designed for imaging in very low Sun illumination conditions, along with DFSAR results.
Presenting the science results from OHRC, scientist at SAC, Ahmedabad, Aditya Kumar Dagar said that while OHRC imaging has “high constraints”, the data can be used to understand boulder distributions around a fresh crater. Boulder is important to understand regolith formation and also to determine future landing sites so that the lander is not jeopardised.
Chandrayaan-2 mission director Ritu Karidhal said that after two years of operation, “the propellant is enough to support more than four (more) years of life”.
Scientists reveal ‘unambiguous presence of water ice’ at permanently shadowed regions of Moon
The ability to combine polarimetric radar images from two wavelengths has also brought forth subsurface features and the polarimetric data helps in identifying the distribution of impact melts.
indianexpress.com
Chandrayaan-2 orbiter payloads made discovery-class findings, says ISRO
The observations of the Chandrayaan-2 orbiter payloads have yielded discovery-class findings, according to the Indian Space Research Organisation (ISRO).There were eight scientific payloads hosted on the orbiter craft.
They are: Chandrayaan-2 Large Area Soft X-ray Spectrometer (CLASS), Solar X-ray Monitor (XSM), CHandra's Atmospheric Compositional Explorer 2 (CHACE 2), Dual Frequency Synthetic Aperture Radar (DFSAR), Imaging Infra-Red Spectrometer (IIRS), Terrain Mapping Camera (TMC 2), Orbiter High Resolution Camera (OHRC), and Dual Frequency Radio Science (DFRS) experiment.
Earlier this week, ISRO opened up its scientific discussions on Lunar Science to "the people of the country, to engage the Indian academia, institutes, students, and people from all disciplines and walks of life", in the form of a two-day "Lunar Science Workshop & Release of Chandrayaan-2 Data".
The workshop commemorated the completion of two years of the Chandrayaan-2 orbiter in the lunar orbit. The events were conducted in virtual mode.
ISRO Chairman and Secretary in the Department of Space (DoS) K Sivan inaugurated the workshop and released the documents on Chandrayaan-2 science results and data products for utilisation by the scientific community.
"The lunar workshop delivered the big news of bunch of discovery-class of findings by Chandrayaan-2", the Bengaluru headquartered India's national space agency said.
The mass spectrometer CHACE-2, in its pursuit to conduct first-ever in-situ study of the composition of the lunar neutral exosphere from a polar orbital platform, detected and studied the variability of the Argon-40 at the middle and higher latitudes of the Moon, depicting the radiogenic activities in the mid and higher latitudes of the Lunar interior, it said.
The discovery of Chromium and Manganese on the lunar surface, which are available in trace quantities, by the CLASS payload was announced.
The observations of microflares of the Sun, during the quiet-Sun period, which provide important clues on the coronal heating problem of the Sun, were made by the XSM payload.
The first-ever unambiguous detection of the hydration features of the Moon was achieved by Chandrayaan-2 with its infra-red spectrometer payload IIRS, which captured clear signatures of Hydroxyl and water-ice on the lunar surface, ISRO said.
The DFSAR instrument could study the subsurface features of the Moon, detected signatures of the sub-surface water-ice, and achieved high resolution mapping of the lunar morphological features in the polar regions, it was stated.
"The observations (of Chandrayaan-2 orbiter payloads) have been yielding intriguing scientific results, which are being published in peer-reviewed journals and presented in international meetings," Sivan said.
Chandrayaan-2, ISRO said, has the feat of imaging the Moon from 100 km lunar orbit with "best-ever" achieved resolution of 25 cm with its OHRC.
The TMC 2 of Chandrayaan-2, which is conducting imaging of the Moon at a global scale, has found interesting geologic signatures of lunar crustal shortening, and identification of volcanic domes, the ISRO said.
The DFRS experiment onboard Chandrayaan-2 has studied the ionosphere of the Moon, which is generated by the solar photo-ionisation of the neutral species of the lunar tenuous exosphere, it was noted.
The science data archived in Indian Space Science Data Centre (ISSDC) at Byalalu, near here, are being disseminated to public through its "PRADAN" portal.
The questions received from the academia, institutes and students were addressed by the ISRO scientists during the two-day deliberations.
A panel discussion provided the opportunity to academia, institutes and students to interact with the ISRO scientists on lunar science and Chandrayaan-2, ISRO said.
Chandrayaan-2 is the second spacecraft in the Indian series of Lunar exploration satellites. It comprised an orbiter, lander named Vikram and rover named Pragyan to explore the unexplored South Polar region of the Moon.
It was launched on July 22, 2019 from the Sriharikota spaceport by GSLV Mk-III. It was inserted into a lunar orbit on August 20, 2019, with firing of thrusters on the orbiter.
The orbiter and lander modules were separated as two independent satellites on September 2, 2019.
Later, Vikram lander's descent was as planned and normal performance was observed up to an altitude of 2.1 km from Lunar surface on September seven, 2019. Subsequently, communication from the lander (with the six-wheeled Pragyan rover accommodated inside it) was lost and the lander had a hard landing on the lunar surface.
A successful soft-landing would have made India the fourth country after the erstwhile Soviet Union, the United States, and China to do so, according to ISRO officials.
The orbiter, placed in its intended orbit around the Moon, will enrich our understanding of the Moon's evolution and mapping of minerals and water molecules in polar regions, using its eight advanced scientific instruments, according to ISRO.
The precise launch and optimised mission management have ensured a long life of almost seven years for the orbiter instead of the planned one year, it said.
Chandrayaan-2 orbiter payloads made discovery-class findings, says ISRO
Earlier this week, ISRO opened up its scientific discussions on Lunar Science to "the people of the country, to engage the Indian academia, institutes, students, and people from all disciplines and walks of life", in the form of a two-day "Lunar Science Workshop & Release of Chandrayaan-2 Data".
Chandrayaan-2 Detects Solar Proton Events, Says ISRO, Explains Phenomenon
Most of these are high energy protons that impact space systems and significantly increase radiation exposure to humans in space. They can cause ionisation on large scales in the earth's middle atmosphere, the space agency said.
Chandrayaan-2 Orbiter has detected solar proton events, Indian Space Agency ISRO said.
Mumbai:
A Large Area Soft X-ray Spectrometer (CLASS), a payload on-board Chandrayaan-2 Orbiter, has detected solar proton events which significantly increase the radiation exposure to humans in space, the Indian Space Research Organisation has said.
The instrument on January 18 also recorded coronal mass ejections (CMEs), a powerful stream of ionised material and magnetic fields, which reach the Earth a few days later, leading to geomagnetic storms and lighting up the polar sky with auroras, the ISRO said on Wednesday.
"Such multi-point observations help us understand the propagation and its impact on different planetary systems," it said.
When the sun is active, spectacular eruptions called solar flares occur that sometimes also spew out energetic particles (called solar proton events or SPEs) into interplanetary space.
Most of these are high energy protons that impact space systems and significantly increase radiation exposure to humans in space. They can cause ionisation on large scales in the earth's middle atmosphere, the space agency said.
Many intense solar flares are accompanied by CMEs, a powerful stream of ionised material and magnetic fields, which reach the earth a few days later, leading to geomagnetic storms and lighting up the polar sky with auroras.
Solar flares are classified according to their strength. The smallest ones are A-class, followed by B, C, M and X. Each letter represents a 10-fold increase in energy output. This means that an M class flare is 10 times more intense than C-class flare and 100 times intense than B-class flare, the ISRO said.
Within each letter class there is a finer scale from 1 to 9 - a M2 flare is twice the strength of M1 flare.
"Recently, there were two M-class solar flares. One flare (M5.5) spewed out energetic particles into interplanetary space and the other flare (M1.5) was accompanied by a CME," the space agency said.
The SPE event was seen by NASA's Geostationary Operational Environmental Satellite (GOES) orbiting around the Earth. However, the CME event was not detected by GOES.
"Chandrayaan-2 Large Area Soft X-ray Spectrometer (CLASS) on-board Chandrayaan-2 Orbiter detected SPE due to an M5.5 class solar flare that occurred on January 20, 2022," the ISRO said.
"The CLASS instrument also detected a CME event as it passed through the moon due to an M1.5 class solar flare that occurred on January 18," it added.
The CME travels at a speed of about 1,000 km/s and it takes about two-three days to reach the Earth.
"The signature of this event is missed by the GOES satellite, as the earth's magnetic field provides shielding from such events. However, the event was recorded by Chandrayaan-2," the ISRO said.
"The CLASS payload on Chandrayaan-2 saw both the SPE and CME events pass by from two intense flares on the Sun," it added.
Planned to land on the moon's south pole, Chandrayaan-2 was launched on July 22, 2019. However, the lander Vikram hard-landed on September 7, 2019, crashing India's dream to become the first nation to successfully land on the lunar surface in its maiden attempt.
The ISRO had then said the mission achieved 98 per cent success as the orbiter continues to share data with the ground station.
Chandrayaan-2 Detects Solar Proton Events, Says ISRO, Explains Phenomenon
A Large Area Soft X-ray Spectrometer (CLASS), a payload on-board Chandrayaan-2 Orbiter, has detected solar proton events which significantly increase the radiation exposure to humans in space, the Indian Space Research Organisation has said.
www.ndtv.com
Chandrayaan-2 makes first observation of global distribution of Argon-40 in lunar exosphere | India News - Times of India
India News: BENGALURU: Isro on Tuesday said that the mass spectrometer onboard the Chandrayaan-2 orbiter, Chandra’s Atmospheric Composition Explorer-2 (CHACE-2), .
timesofindia.indiatimes.com
That OHRC camera on the CY-2 orbiter has been absolutely fantastic. Shame we aren't doing a follow up to that:
Chandrayaan-2 unveils the effect of the Earth’s geomagnetic tail on the Lunar ionosphere plasma
March 07, 2025
Figure: The left panel displays the altitude profile of integrated total electron content (iTEC) observed on November 8, 2022 at ~ 18:00 UTC, near the north pole at 740 latitude and 840 W longitude, and the corresponding electron density profile (EDP) is shown in the right panel (black curve). The error bars in green and pink colors indicate the σ and 3σ variations in electron density respectively with σ representing the standard deviation. The area shaded in cyan has negative electron density which stands for noise. The purple-colored profile represents the Lunar Ionospheric Model (LIM) output, and PCE stands for Photo Chemical Equilibrium. The middle panel of the figure shows the simulated electron density profile at the observation site when the Moon is inside the Geo-tail in the absence of a crustal magnetic field.
In a major finding, scientists from Space Physics Laboratory, VSSC, analyzing radio signals from India’s Chandrayaan-2 (CH-2) orbiter – which is in good health and providing data - have revealed that the Moon’s ionosphere exhibits unexpectedly high electron densities when it enters the Earth’s geomagnetic tail. These finding sheds new light on how plasma behaves in the lunar environment and suggests a stronger influence of the Moon’s remnant magnetic fields than previously thought.
The scientists have used an innovative method to study the plasma distribution around moon. In this method they conducted experiments using the S-band Telemetry and Telecommand (TTC) radio signals in a two-way radio occultation experiment, tracking CH-2’s radio transmissions through the Moon’s plasma layer. These signals were received at the Indian Deep Space Network (IDSN), Byallalu, Bangalore. The results revealed a surprisingly high electron density of approximately 23,000 electrons per cubic centimeter in the lunar environment, comparable to densities observed in the Moon’s wake region (previously discovered by the same team) and nearly 100 times higher than those on the sunlit side of the Moon.
The Moon passes through Earth’s extended magnetic field, or "geotail," for nearly 4 days in each orbit. During this period, the moon is shielded from direct solar wind and was thought to have lower plasma densities due to free diffusion along Earth's magnetic field lines. However, the Chandrayaan-2 observations challenge this assumption. Scientists have proposed that the presence of remnant lunar crustal magnetic fields could be trapping plasma, preventing its diffusion, and leading to localized enhancements in electron density. To confirm this, they used in-house Three-Dimensional Lunar Ionospheric Model (3D-LIM) developed at SPL/VSSC, which simulated plasma dynamics under different conditions. The simulations showed that to sustain such high plasma densities, the ionosphere must be in photochemical equilibrium, a condition only achievable in the geotail when crustal magnetic fields are present. The model also suggested a localized reduction in neutral Argon (Ar) and Neon (Ne) densities near the Moon’s poles, aligning with previous spacecraft observations.
High plasma densities can influence radio communications, surface charging effects, and interactions with lunar dust, all of which are important for the upcoming robotic and crewed missions near lunar orbital magnetic field region. Understanding how the lunar ionosphere behaves in different space environments will also improve planning for lunar habitats, particularly in regions influenced by crustal magnetic fields.
The study marks a significant step in unravelling the complex plasma environment around the Moon and highlights the continued impact of Chandrayaan-2’s science mission in advancing lunar research. As more nations gear up for Moon exploration, findings like these will play a crucial role in shaping the future of lunar science and technology.
Reference: "Lunar Ionosphere in the Geotail Region as Observed by Chandrayaan-2 Orbiter Using Two-way Radio Occultation Measurements”, Keshav R. Tripathi, R. K. Choudhary, and K. M. Ambili, The Astrophysical Journal - Letters (DOI: 10.3847/2041-8213/adb3a7).
Chandrayaan-2 unveils the effect of the Earth’s geomagnetic tail on the Lunar ionosphere plasma
March 07, 2025
Figure: The left panel displays the altitude profile of integrated total electron content (iTEC) observed on November 8, 2022 at ~ 18:00 UTC, near the north pole at 740 latitude and 840 W longitude, and the corresponding electron density profile (EDP) is shown in the right panel (black curve). The error bars in green and pink colors indicate the σ and 3σ variations in electron density respectively with σ representing the standard deviation. The area shaded in cyan has negative electron density which stands for noise. The purple-colored profile represents the Lunar Ionospheric Model (LIM) output, and PCE stands for Photo Chemical Equilibrium. The middle panel of the figure shows the simulated electron density profile at the observation site when the Moon is inside the Geo-tail in the absence of a crustal magnetic field.
New study reveals surprisingly high electron densities in the Lunar environment, hinting at the potential role of lunar crustal magnetic fields in shaping plasma dynamics.
In a major finding, scientists from Space Physics Laboratory, VSSC, analyzing radio signals from India’s Chandrayaan-2 (CH-2) orbiter – which is in good health and providing data - have revealed that the Moon’s ionosphere exhibits unexpectedly high electron densities when it enters the Earth’s geomagnetic tail. These finding sheds new light on how plasma behaves in the lunar environment and suggests a stronger influence of the Moon’s remnant magnetic fields than previously thought.
The scientists have used an innovative method to study the plasma distribution around moon. In this method they conducted experiments using the S-band Telemetry and Telecommand (TTC) radio signals in a two-way radio occultation experiment, tracking CH-2’s radio transmissions through the Moon’s plasma layer. These signals were received at the Indian Deep Space Network (IDSN), Byallalu, Bangalore. The results revealed a surprisingly high electron density of approximately 23,000 electrons per cubic centimeter in the lunar environment, comparable to densities observed in the Moon’s wake region (previously discovered by the same team) and nearly 100 times higher than those on the sunlit side of the Moon.
The Moon passes through Earth’s extended magnetic field, or "geotail," for nearly 4 days in each orbit. During this period, the moon is shielded from direct solar wind and was thought to have lower plasma densities due to free diffusion along Earth's magnetic field lines. However, the Chandrayaan-2 observations challenge this assumption. Scientists have proposed that the presence of remnant lunar crustal magnetic fields could be trapping plasma, preventing its diffusion, and leading to localized enhancements in electron density. To confirm this, they used in-house Three-Dimensional Lunar Ionospheric Model (3D-LIM) developed at SPL/VSSC, which simulated plasma dynamics under different conditions. The simulations showed that to sustain such high plasma densities, the ionosphere must be in photochemical equilibrium, a condition only achievable in the geotail when crustal magnetic fields are present. The model also suggested a localized reduction in neutral Argon (Ar) and Neon (Ne) densities near the Moon’s poles, aligning with previous spacecraft observations.
High plasma densities can influence radio communications, surface charging effects, and interactions with lunar dust, all of which are important for the upcoming robotic and crewed missions near lunar orbital magnetic field region. Understanding how the lunar ionosphere behaves in different space environments will also improve planning for lunar habitats, particularly in regions influenced by crustal magnetic fields.
The study marks a significant step in unravelling the complex plasma environment around the Moon and highlights the continued impact of Chandrayaan-2’s science mission in advancing lunar research. As more nations gear up for Moon exploration, findings like these will play a crucial role in shaping the future of lunar science and technology.
Reference: "Lunar Ionosphere in the Geotail Region as Observed by Chandrayaan-2 Orbiter Using Two-way Radio Occultation Measurements”, Keshav R. Tripathi, R. K. Choudhary, and K. M. Ambili, The Astrophysical Journal - Letters (DOI: 10.3847/2041-8213/adb3a7).
Chandrayaan-2 unveils the effect of the Earth’s geomagnetic tail on the Lunar ionosphere plasma