Radio Astronomy & Telescopes
Science & Technology
- PYQs5
- Articles1
Background
Highlights technological advancements in space science, India's participation in global scientific projects, and the role of advanced instrumentation in pushing the boundaries of human knowledge and understanding of the cosmos.
Radio astronomy is a subfield of astronomy that studies celestial objects at radio frequencies. Unlike optical telescopes, radio telescopes can detect radiation that penetrates cosmic dust and gas, revealing phenomena invisible to the human eye and providing unique insights into the universe's coldest and most energetic processes.
Facts & tables
- Principle
- Studies celestial objects at radio frequencies
- Advantage
- Can penetrate cosmic dust and gas, revealing hidden structures
- Key Facility (Current)
- LOFAR (Low Frequency Array) for ultra-sensitive low-frequency surveys
- Key Facility (Future)
- Square Kilometre Array Observatory (SKA) as a next-generation instrument
| Type | Reference |
|---|---|
| Conceptual area | Observational Astronomy |
| Conceptual area | Electromagnetic Spectrum |
| Body | Role |
|---|---|
| LOFAR (Low Frequency Array) | Instrument used for the discovery |
| Square Kilometre Array Observatory (SKA) | Future facility for advanced radio astronomy |
Prelims angle
Prelims angle: Multi-statement analysis
Prelims angle: Factual recall
- Principle: Detection of radio waves from celestial objects.
- Advantages: Penetrates dust/gas, reveals non-optical phenomena.
- Key Instruments: LOFAR (Low Frequency Array), SKA (Square Kilometre Array).
- Applications: Studying active galaxies, cosmic evolution, faint structures.
- Future: AI/ML techniques for data analysis in upcoming surveys.
| Year | Framing tags |
|---|---|
| 2024 | Statement-based questions, Conceptual understanding |
| 2023 | Multi-statement analysis, Factual recall |
| 2022 | Multi-statement analysis, Conceptual understanding |
| 2019 | Multi-statement analysis, Conceptual understanding |
| 2018 | Multi-statement analysis, Conceptual understanding |
Timeline
-
Observational Astronomy
Conceptual area
-
Electromagnetic Spectrum
Conceptual area
-
Prelims 2018
Multi-statement analysis, Conceptual understanding
-
Prelims 2019
Multi-statement analysis, Conceptual understanding
-
Prelims 2022
Multi-statement analysis, Conceptual understanding
-
Prelims 2023
Multi-statement analysis, Factual recall
-
Prelims 2024
Statement-based questions, Conceptual understanding
-
Indian team discovers rare ‘bow and arrow’ radio galaxy two billion light years from Earth
Radio astronomy utilizes specialized telescopes to observe the universe at radio wavelengths, offering a unique perspective on cosmic phenomena by detecting radiation that optical telescopes cannot. Facilities like LOFAR and the upcoming SKA are crucial for these discoveries, enabling detailed studies of faint and diffuse cosmic structures.
See also
Past papers
2018–2024 · 5 questions
In the news
Indian team discovers rare ‘bow and arrow’ radio galaxy two billion light years from Earth
Radio astronomy utilizes specialized telescopes to observe the universe at radio wavelengths, offering a unique perspective on cosmic phenomena by detecting radiation that optical telescopes cannot. Facilities like LOFAR and the upcoming SKA are crucial for these discoveries, enabling detailed studies of faint and diffuse cosmic structures.
Try these PYQs
Consider the following pairs :
Objects in space: Description
1. Cepheids: Giant clouds of dust and gas in space
2. Nebulae: Stars which brighten and dim periodically
3. Pulsars: Neutron stars that are formed when massive stars run out of fuel and collapse
How many of the above pairs are correctly matched?
* Pair 1 is incorrect: Cepheids are actually stars that brighten and dim periodically, not giant clouds of dust and gas. * Pair 2 is incorrect: Nebulae are giant clouds of dust and gas in space, not stars that brighten and dim periodically. Thus, the first two pairs are reversed. * Pair 3 is correct: Pulsars are rapidly rotating neutron stars that are formed when massive stars exhaust their fuel and collapse. * So out of the 3 pairs given, only 1 pair (pair 3) is correctly matched.
For the measurement/estimation of which of the following are satellite images/remote sensing data used?
1. Chlorophyll content in the vegetation of a specific location
2. Greenhouse gas emissions from rice paddies of a specific location
3. Land surface temperatures of a specific location
Select the correct answer using the code given below.
Remote sensing is the process of detecting and monitoring the physical characteristics of an area by measuring its reflected and emitted radiation at a distance from the targeted area. Statement 1 is correct. Satellite images and remote sensing data can indeed be used to estimate the chlorophyll content in vegetation. This is done by measuring the reflectance of light from the vegetation. The chlorophyll in plants absorbs light for photosynthesis, and the amount of light reflected back can give an estimate of the chlorophyll content. Statement 2 is correct. Satellite images and remote sensing data can also be used to estimate greenhouse gas emissions. This is done by detecting the radiations emitted by the substances in the rice paddies. Statement 3 is correct. Satellite images and remote sensing data can be used to measure land surface temperatures as well. This is done by detecting the infrared radiation emitted by the land surface. Therefore, all three parameters can be measured or estimated using satellite images or remote sensing data.
If a major solar storm (solar-flare) reaches the Earth, which of the following are the possible effects on the Earth?
1. GPS and navigation systems could fail.
2. Tsunamis could occur at equatorial regions.
3. Power grids could be damaged.
4. Intense auroras could occur over much of the Earth.
5. Forest fires could take place over much of the planet.
6. Orbits of the satellites could be disturbed.
7. Shortwave radio communication of the aircraft flying over polar regions could be interrupted.
Select the correct answer using the code given below:
Out of the listed effects of a major solar storm, the most likely ones are Statement 1 is correct. A solar storm can disrupt the Earth's ionosphere, which can affect the signal transmission of GPS and other radio-based navigation systems. Statement 3 is correct. Strong currents induced by the solar storm in power grids can damage transformers and cause widespread blackouts. Statement 4 is correct. Solar storms can energize particles in the Earth's magnetosphere, leading to spectacular auroras at lower latitudes than usual. Statement 6 is correct. The drag from a solar storm can alter the orbits of satellites, especially those in lower Earth orbit. Statement 7 is correct. Similar to GPS, radio communication can be affected by disturbances in the ionosphere. Statement 2 is incorrect. Tsunamis are caused by underwater earthquakes or volcanic eruptions, not solar storms. Statement 5 is incorrect. While a solar storm could potentially ignite some fires through electrical sparks, this is not a widespread effect. Therefore, codes 2 and 5 should not form the part of answer.
With reference to radioisotope thermoelectric generators (RTGs), consider the following statements:
1. RTGs are miniature fission reactors.
2. RTGs are used for powering the onboard systems of spacecrafts.
3. RTGs can use Plutonium-238, which is a by-product of weapons development.
Which of the statements given above are correct?
* Statement 1: Incorrect. RTGs (Radioisotope Thermoelectric Generators) are not miniature fission reactors. Fission reactors use nuclear fission, a process of splitting atoms to release a tremendous amount of energy. RTGs, on the other hand, utilize the natural radioactive decay of isotopes to generate heat, which is then converted to electricity through a process called thermoelectricity. * Statement 2: Correct. RTGs are indeed a reliable power source for spacecraft, especially those venturing far from the sun where solar panels become ineffective. They provide consistent, low-level electric power for extended periods, making them ideal for probes, satellites, and rovers in deep space. * Statement 3: Correct. Plutonium-238 is a common isotope used in RTGs due to its long half-life (the time it takes for half of the material to decay) and its ability to generate a steady heat output from its decay process. While it can be a byproduct of weapons development, there are also alternative ways to produce Plutonium-238 specifically for peaceful applications like RTGs.
Consider the following phenomena :
1. Light is affected by gravity.
2. The Universe is constantly expanding.
3. Matter warps its surrounding space-time.
Which of the above is/are the prediction/predictions of Albert Einstein's General Theory of Relativity, often discussed in media?
Statement 1 is correct: According to Einstein's General Theory of Relativity, gravity can bend light. This phenomenon is known as gravitational lensing. Statement 2 is correct: The General Theory of Relativity led to the prediction of an expanding universe, which has been confirmed by observational evidence. Statement 3 is correct: According to the General Theory of Relativity, the presence of matter and energy warps the fabric of space and time around it, which is the underlying cause of the gravitational force. So, all three statements are correct.