Month: January 2024

• NASA’s Mars helicopter, Ingenuity, has reconnected with Earth following a brief communication loss during its 72nd flight on the Red Planet.
• This astonishing solar-powered robotic helicopter has achieved unprecedented achievements in interplanetary aviation, including powered, controlled flight on Mars.

About Ingenuity 

• Ingenuity made its first landing on Mars on February 18, 2021, alongside the Perseverance Rover. On April 19 of that year, it made the first powered extraterrestrial flight in human history.
• Launch and Deployment: On July 30, 2020, NASA launched a spacecraft carrying the Perseverance rover with Ingenuity aboard. On April 4, 2021, the helicopter was deployed on the Martian surface after finding an appropriate “airfield” position.
• Experimental Purpose: Ingenuity’s primary purpose was to test powered, controlled flight on another celestial body.
• history Flight: During its first flight, Ingenuity hovered, covered the same area, and remained airborne for an impressive 39.1 seconds, setting a history record.

Challenges and Impressive Record

• Vast Distances: Despite the comparatively short travel time, Mars’ distance from Earth of nearly 225 million kilometres causes signal delays of 5 to 20 minutes.
• Ingenuity must withstand Mars’ harsh conditions, which include low atmospheric density, “continent-sized” dust storms, and other threats.

The Significance of Mars Flight

• Historical Milestone: On April 19, 2021, Ingenuity’s first flight celebrated two great milestones. First and foremost, it was the first aeroplane to fly on another planet. Second, it worked in Mars’ thin atmosphere, which was unsuitable for conventional flight.
• Challenges of Martian Flight: Ingenuity’s flight on Mars proved difficult due to the planet’s reduced gravity, one-third that of Earth, and its relatively thin atmosphere, with only 1% of Earth’s surface pressure.
• Autonomous Operation: Ingenuity is an autonomous aircraft piloted by onboard guidance, navigation, and control systems that use algorithms developed by NASA’s Jet Propulsion Laboratory. Perseverance serves as a vital link between the helicopter and Earth.

Evolving Mission Role

• Ingenuity’s mission grew beyond limited flights to include scouting and exploration. It helped Perseverance navigate Martian terrain efficiently, avoiding unexceptional rocks and increasing mission efficiency.
• Impressive flying Record: Prior to the current contact breakdown, Ingenuity conducted 72 flights, amassing more than 128 minutes of flying time and travelling a total distance of 17.7 kilometres, according to the mission’s flight log.

Source: https://www.nasa.gov/news-release/nasas-ingenuity-mars-helicopter-succeeds-in-historic-first-flight/

• As significant sections of North India, including Bihar, Uttar Pradesh, Uttarakhand, Haryana, Delhi, and Punjab, experience severe fog, the India Meteorological Department (IMD) has issued alerts and advisories to keep inhabitants aware of the current circumstances.
• This essay aims to clarify the science underlying these alerts and the function of the INSAT 3D satellite in delivering critical data for fog monitoring.

Fog Situation in North India

• Persistent fog: Since December 2023, various portions of North India have been blanketed in dense fog.
• IMD Warnings: On January 16, the IMD issued “very dense fog” warnings in numerous states, including Haryana, Chandigarh, Delhi, Uttar Pradesh, Punjab, and Madhya Pradesh, with visibility predicted to fall below 50 metres at night and in the morning.

Decoding satellite images.

• Perspectives from INSAT 3D: The INSAT 3D satellite monitors foggy conditions using photographs.
• Solar Reflectance and Brightness Temperature: These photos’ colours are influenced by two factors: solar reflectance and brightness temperature.
• Solar Reflectance: The ratio of solar energy reflected by a surface to the amount of energy received.
• Brightness Temperature: Relates an object’s temperature to the brightness of its surface as measured at various wavelengths.

Day’s Microphysics Data

• Solar Reflectance at Three Wavelengths: INSAT 3D’s ‘day microphysics’ component examines solar reflectance across three wavelengths: 0.5 µm (visible radiation), 1.6 µm (shortwave infrared radiation), and 10.8 µm (thermal infrared radiation).
• Colour Determination: The intensity of signals at these wavelengths determines the RGB (red-green-blue) colours in the picture.
• These photos are useful for analysing cloud kinds, thunderstorm phases, snow identification, and fire detection.

Night Microphysics Data

• INSAT 3D’s ‘night microphysics’ component determines two colours based on the difference between two thermal infrared signals.
• Colour Variables: The red colour corresponds to the difference between 12 µm and 10 µm signals, green to 10.8 µm and 3.9 µm signals, and blue to the intensity of the 10.8 µm signal.
• Identifying features: Night microphysics data helps to determine cloud kinds and their temperature differences.

Combining Day and Night Data.

• Comprehensive Insights: Meteorologists use day and night microphysics data to examine moisture droplets, temperature fluctuations, and the development, evolution, and depletion of meteorological phenomena like hurricanes.
• Advanced Warning Systems: Proposed uses include forecasting thunderstorms one to three hours in advance.

Radiometers & Sounders

• INSAT 3D and 3DR employ radiometers to monitor spectral properties and atmospheric sounders to analyse temperature, humidity, and water vapour levels.
• Improved Technology: Compared to their predecessors, these satellites have significantly higher spatial resolution and spectrum channels, improving India’s weather monitoring capabilities.

Future with INSAT 3DS

• Continued Advancements: The Indian Space Research Organisation intends to launch the INSAT 3DS meteorological satellite in February 2024.
• Enhanced Capabilities: This satellite will build on the achievements of its predecessors, improving India’s weather monitoring and warning capabilities.

Source: https://www.thehindu.com/sci-tech/science/insat-3d-night-microphysics-fog-map-north-india-explained/article67747369.ece

• The Indian Space Research Organisation (ISRO) has developed an innovative Distress Alert Transmitter (DAT) to improve the safety of fishermen at sea.
• This second-generation DAT, known as DAT-SG, has increased capabilities and features that will transform how emergency messages are conveyed from fishing boats.

About the Distress Alert Transmitter (DAT-SG).

• Operational Since 2010: The original version of DAT went live in 2010, allowing fisherman to send emergency signals via a communication satellite.
• The Indian Mission Control Centre (INMCC), a central control station, received messages and interpreted alarm signals to identify the troubled fishing boat.
• Coordination with MRCCs: The collected information was then provided to Maritime Rescue Coordination Centres (MRCCs) operated by the Indian Coast Guard (ICG), allowing for coordinated search and rescue efforts.
• More than 20,000 DATs were deployed and used for distress signalling.

Evolution to DAT-SG.

• ISRO used developments in satellite communication and navigation to develop the second-generation DAT (DAT-SG).
• DAT-SG now features an acknowledgement feature, which assures fisherman that their distress signal has been heard and that assistance is on its way.
• Two-Way Communication: In addition to transmitting distress signals, DAT-SG can receive communications from control centres. This enables the broadcast of advance warnings for hazardous weather conditions, cyclones, tsunamis, and other catastrophes, allowing fishermen to make educated decisions about their safety.
• Enhanced Fishing Zone Information: DAT-SG also provides fishermen with information on possible fishing zones at regular intervals, allowing them to maximise their harvest while conserving time and fuel.
• Mobile Connectivity: DAT-SG can communicate with mobile phones via Bluetooth, and messages may be displayed in the fishermen’s local language via a specific mobile app.

Centralised Control and Coordination

• Sagarmitra Network: INMCC, the central control station, uses a web-based network management system named Sagarmitra. This system keeps track of registered DAT-SGs and allows MRCCs to obtain information in real time.
• Real-time Coordination: Sagarmitra allows Indian Coast Guard troops to respond to distress calls quickly, improving search and rescue operations.
• DAT-SG services are accessible 24 hours a day, seven days a week, to provide ongoing help to fishermen experiencing crises at sea.

Source: https://www.thehindu.com/news/national/karnataka/isro-develops-second-generation-distress-alert-transmitter/article67752250.ece#:~:text=The%20DAT%2DSG%20has%20the,the%20distress%20alert%20from%20sea.&text=%E2%80%9CThis%20gives%20an%20assurance%20to,receive%20messages%20from%20control%20centres.

• The study of ancient DNA from early European populations, which dates back up to 34,000 years, provides vital insights into the origins of multiple sclerosis (MS) and throws light on many genetic features in current Europe.
• By comparing ancient and current DNA, researchers discovered a complicated interplay between genetic variations that formerly protected against animal-borne illnesses and the increasing risk of MS in modern populations.

What is multiple sclerosis?

• MS is a chronic autoimmune illness of the central nerve system.
• It causes a variety of symptoms, including weariness, muscular weakness, numbness, and eye issues.
• MS can take many distinct forms, the most common of which is relapsing-remitting MS.
• While there is no cure, there are therapies available to help control symptoms and reduce the disease development.

Ancient DNA Role

•  It plays a key role in genomic exploration. Ancient DNA from 1,664 individuals in Western Europe and Asia was sequenced, allowing for a thorough examination of genetic changes across time.
• Modern Comparisons: To discover evolutionary transitions, these ancient genomes were compared to DNA from the UK Biobank, which included over 410,000 “white-British” people.

Insights into Multiple Sclerosis 

• Protective variations: A study found that genetic variations linked to an elevated risk of MS were originally used to defend against illnesses transmitted by Yamnaya cattle herders.
• Bronze Age Migration: Around 5,000 years ago, the Yamnaya people migrated to Western Europe from territories such as current Ukraine and southern Russia.

Regional Disparities in Mississippi

• North Europeans: Northern Europeans have the highest MS frequency, notably in nations like Ireland, Iceland, Norway, and Sweden, where Yamnaya-related genetic heritage is more common.
• Southern Europeans had a lower prevalence of MS than Neolithic farmers due to genetic differences.

Implications of Disease and Evolution

• Changing Genetic features: The findings show how formerly favourable genetic features may become deleterious as settings and living situations change.
• Pathogenic infections increased throughout the Bronze Age due to increasing closeness between people and domestic animals, resulting in the development of protective genetic variations.

Recalibrating Immune Systems.

• Reinterpretation of MS: This study provides a fresh viewpoint on MS, emphasising the need of recalibrating the immune system rather than suppressing it, taking into account the transition from past to present hygienic conditions.
• Broader Health Implications: The study’s findings apply to a variety of health issues, including the risk of Alzheimer’s disease and type 2 diabetes among Eastern Europeans.

Source: https://www.thehindu.com/sci-tech/science/dna-from-ancient-europeans-reveals-surprising-multiple-sclerosis-origins/article67733763.ece#:~:text=DNA%20obtained%20from%20the%20bones,people%20from%20animal%2Dborne%20diseases.

• In 2014, the Royal Swedish Academy of Sciences proclaimed that “the 21st century will be lit by LED lamps,” recognising the importance of Light-Emitting Diodes (LEDs) in influencing the future of lighting technology.
• This article goes into the interesting world of diodes, LEDs, and their role in modern technology.

Understanding diodes

• Diode Basics: A diode is a tiny electrical component having two terminals: anode and cathode. Its principal function is to enable current to flow in just one way via a p-n junction.
• A p-n junction is made up of two neighbouring materials: a p-type with positive charge carriers known as holes, and an n-type with negative charge carriers known as electrons. Electrons may readily flow from the n-type to the p-type but not the other way around, allowing the diode to regulate current in one direction alone.
• Anode and Cathode: The anode terminal is linked to the p-type material, while the cathode is connected to the n-type material. These terminals determine the diode’s directionality.

The birth of light-emitting diodes (LEDs)

• Electroluminescence: LEDs are light-emitting diodes. Electrons, which have greater energy levels than holes, release energy when they occupy holes in the p-n junction. If this energy falls inside the visible spectrum, it emits light, a process known as electroluminescence.
• LEDs create certain light colours by ensuring that electron-hole recombination produces a correct quantity of energy, which is determined by the band gap.

The Band Gap’s significance

• It lies in the fact that electrons can only have specific energy levels. These electrons typically occupy the lowest energy levels accessible, resulting in conductors, insulators, and materials with a band gap.
• Band Gap’s Role: A band gap denotes the energy threshold necessary for electrons to transition from lower to higher energy levels, allowing materials to conduct electricity.
• LED and Band Gap: The energy emitted during electron-hole recombination in LEDs correlates to the band gap, which determines the light’s colour.

The colour palette of LEDs 

• It has evolved over four decades, with red and green LEDs coming first. The objective was to create gallium nitride crystals with precise electroluminescent characteristics.
• Primary Colours: LEDs may emit red, green, and blue light, providing a diverse colour pallet. Combining multiple LEDs results in a wide range of colours on display boards and displays.
• Breakthrough: In the late 1980s, Japanese researchers Isamu Akasaki, Hiroshi Amano, and Shuji Nakamura achieved a big breakthrough by producing a brilliant blue LED out of gallium nitride. Their achievements earned them the 2014 Nobel Prize in Physics.

Advantages of LEDs

• LEDs are more efficient than incandescent bulbs and fluorescent lights, producing more light per watt of electricity. This is one of its advantages.
• LEDs are extremely durable, resulting in less material waste and lower maintenance costs.
• LEDs are used in a variety of applications, including consumer electronics and signs, greenhouse illumination, and air quality monitoring.
• Colour versatility: LEDs can emit a variety of colours and frequencies, making them suitable for a wide range of applications.

Future Prospects

• Haitz’s Law: Like Moore’s law, LEDs have followed Haitz’s law, which predicts cost reduction and greater light output over time.
• Innovations: Ongoing research investigates skin-embedded LEDs, organic LEDs, and efficient LEDs produced from perovskites, all of which promise significant breakthroughs in lighting technology.

Source: https://www.sciencedirect.com/topics/engineering/light-emitting-diode