Editorial 1: Chasing the Sun
Recent Context:
- Having planted its feet firmly on the Moon, the Indian Space Research Organisation (ISRO) is now headed towards the Sun with Aditya L1 mission.
- Aditya-L1 will be launched on September 2 at 11:50 am from Sriharikota.
- The spacecraft will travel 1.5 million km from the Earth to the Lagrange 1 or L1 point between the Earth and the Sun
What is the Aditya-L1 mission?
- The Aditya-L1 mission will be launched by the Polar Satellite Launch Vehicle (PSLV) carry the 1,475-kg spacecraft to an elliptical orbit around the Earth. The spacecraft, which will carry seven scientific payloads, is more than two times lighter than the one to the Moon.
- Like the Chandrayaan-3 mission, the orbit as well as the velocity of the spacecraft around the Earth will be increased till it is slingshot towards the Sun. The distance to L1 point will be covered in nearly four months. The spacecraft will then be inserted into a halo orbit around the L1 point. It will collect data for five years.
What is the L1 point?
- There are five Lagrange points, L1 to L5, between any two celestial bodies.
- These points can act as parking spots in space where the gravitational pull of the celestial objects equals the centripetal force required to keep a satellite in orbit
- First, going to Lagrange 1 places the spacecraft at a point beyond the Moon between the Earth and the Sun. This offers the spacecraft an unobstructed view of the Sun even during phenomena like an eclipse.
- Second, with the mission covering only 1% of the distance between the Earth and Sun, the payloads will be able to look directly at the Sun. “This position will allow the main payload, VLEC, to look directly into the source of coronal mass ejection.
What are the science objectives of Aditya-L1?
- Unlike the current round of Moon missions which are focused on exploring opportunities for resource utilisation and extraction, and setting up facilities for longer term stays. The Aditya L1 mission aims for better understanding of explosive processes happening within the Sun can potentially result in early warning systems for solar eruptions that threaten space-based assets like communication or navigation systems. The study of the Sun can give insights about the processes happening inside other stars as well.
- The payloads on the mission will study the upper atmospheric layers of the Sun called chromosphere and corona. They will study the expulsion of plasma and magnetic fields called coronal mass ejection (CME). The magnetic field of the corona and the drivers of the space weather will also be studied.
- Importantly, it might provide clues to scientists about a long-standing mystery: why the not-so-bright corona of the Sun is a million degree C hot, when the temperature on the surface of the Sun is just about 5,500-degree C.
- It will also help scientists understand the reasons behind acceleration of particles on the Sun, which leads to solar winds.
What are the payloads?
- The main payload is the Visible Emission Line Coronagraph (VLEC), will help study the solar corona from the lowermost part upwards. The VELC can image the solar corona down to 1.05 times the solar radius, the closest any such payload has imaged.
- The Solar Ultraviolet Imaging Telescope (SUIT) will capture the UV image of the solar photosphere and chromosphere. It will help study the variation in light energy emitted.
- The Solar Low Energy X-ray Spectrometer (SoLEXS) and High Energy L1 Orbiting X-ray Spectrometer (HEL1OS), will study X-ray flares.
- The Aditya Solar wind Particle EXperiment (ASPEX) and Plasma Analyser Package for Aditya (PAPA) are designed to study the solar wind and energetic ions
Why study the Sun from space?
- The Sun is the nearest star to us and therefore can be studied in much greater detail than others.
- Studying the Sun can also help us understand more about other stars. While the Sun supports all life on Earth, it also has various explosive phenomena. These can damage our satellites and communication systems. Studying the Sun may help in providing early warnings for such events.
- Therefore, “The various thermal and magnetic phenomena on the Sun are of extreme nature. Thus, the Sun provides a good natural laboratory to understand them, which cannot be directly studied in the lab
Conclusion:
- It is important to study the Sun from space because the Earth’s atmosphere and the magnetic field act as protective shields that block out harmful radiations, such as UV light. This means studying the Sun from the Earth can’t provide a complete picture.
- Therefore, With Aditya-L1, the ISRO would be travelling much further in space, 1.5 million kilometres, than it did with Chandrayaan-3 whose destination was barely 4 lakh km from Earth. For ISRO, these are only the beginnings. Many more great journeys await.
Editorial 2: How air pollution is cutting short lives in South Asia
Recent context:
- Recently, the report, ‘Air Quality Life Index (AQLI) Annual Update 2023’, was published by the University of Chicago’s Energy Policy Institute.
- AQLI measures the impact of particulate pollution on life expectancy and the latest report analysed particulate matter data from 2021 to determine its impact on life expectancy.
Major outcomes of the report: According to the report,
- The region, which is home to the most polluted countries of Bangladesh, India, Nepal, and Pakistan, accounts for more than half of the total life years lost globally due to high pollution.
- Tobacco use, for instance, reduces life expectancy in these countries by as much as 2.8 years; unsafe water and sanitation by as much as 1 year; and alcohol use by half a year but the Air pollution is reducing the life span of people living in South Asia by 5.1 years
Report’s outcomes on India’s air pollution
- India is the second most polluted nation after Bangladesh, annual average particulate pollution level surpasses the WHO guideline. Moreover, 67.4% of the population live in areas that exceed the country’s own national air quality standard of 40 µg/m3.
- The report said from 1998 to 2021, average annual particulate pollution increased by 67.7%, further reducing average life expectancy by 2.3 years.
- Between 2020 and 2021, PM2.5 level in India increased from 56.2 µg/m3 to 58.7 µg/m3, which is 10 times more than the WHO guideline. (WHO, annual average concentrations of PM 2.5 limit 5 µg/m3.)
- The most polluted region of the country is “the Northern Plains, where more than a half billion people live”. Notably, Delhi’s annual average PM2.5 level in 2021 was found to be 126.5 µg/m3 and the life expectancy of an average person living in the city has shortened by 11.9 years.
Reasons behind the spike in air pollution
- The uptick in air pollution in South Asia is not a surprise, the report mentioned. It’s an outcome of
- rapid industrialisation,
- economic development,
- Increase in number of vehicles and
- population growth, which increased energy demand and fossil fuel use across the region.
- Not only this, electricity production using fossil fuels tripled between 1998 and 2017 in Bangladesh, India, Nepal and Pakistan combined. Although high energy use has contributed to better living standards and economic output in these countries, the consequent increase in particulate pollution has had grave repercussions.
Adverse effects of particulate pollution
- One of the most harmful atmospheric pollutants is PM 2.5. Sized at just 2.5 micrometres, which is around 3% of the diameter of a human hair, it can easily enter the circulatory system of humans through the nose and throat. PM 2.5 particles can cause chronic diseases such as asthma, heart attack, bronchitis and other respiratory problems.
- Along with they are one the major reasons for global warming
Conclusion:
- Therefore, there is need for collaborative efforts at national and international level to check on air pollution which will be helpful to minimize the impact of air pollution on health and will also check on global warming.