Indian scientists find new way to measure distances in deep space
UPSC Prelims regularly features questions on cutting-edge scientific discoveries, especially those involving Indian scientists. Pulsars are a well-established concept in science & technology syllabus segments covering astronomy and space science. A new Indian-developed method for measuring cosmic distances adds to the growing list of ISRO/Indian science achievements relevant for prelims.
Key facts
- Pulsars are dense, rapidly spinning remnant cores of dead stars (neutron stars).
- They emit beams of radio waves similar to a lighthouse beam sweeping across the sea.
- Pulsars have an extraordinarily stable spin rate, making their radio pulses arrive at highly regular intervals.
- Indian scientists have developed a new method to measure distances in deep space using pulsar observations.
- Pulsars are among the most precise natural clocks known in the universe.
The dense and rapidly spinning remnant cores of dead stars are called pulsars; they emit beams of radio waves that sweep across the earthlike light from a lighthouse sweeps across ships at sea; pulsars have an extraordinarily fixed spinning rate, so the pulses arrive very regularly.
Concepts to know
A pulsar is a highly magnetised, rapidly rotating neutron star that emits beams of electromagnetic radiation (usually radio waves). Because their spin rates are extraordinarily stable, pulsars act as precise cosmic clocks and can be used for navigation and distance measurement in deep space.
A neutron star is the ultra-dense remnant left after a massive star undergoes a supernova explosion. It is composed almost entirely of neutrons and can have a mass greater than the Sun packed into a radius of about 10 km.
The cosmic distance ladder refers to successive methods used to measure distances in space, from nearby parallax measurements to standard candles like Cepheid variables and Type Ia supernovae. Pulsars can serve as a new rung in this ladder for deep-space measurement.
Radio astronomy is the study of celestial objects that emit radio waves. India's Giant Metrewave Radio Telescope (GMRT) near Pune is one of the world's premier facilities for radio astronomy, including pulsar studies.
GMRT, operated by the National Centre for Radio Astrophysics (NCRA-TIFR) near Pune, is one of the largest and most sensitive radio telescope arrays in the world, frequently used for pulsar research and other deep-space observations.
Linked previous-year questions
The UPSC questions this story connects to.
Which one of the following is a reason why astronomical distances are measured in light-years? (a) Distances among stellar bodies do not change. (b) Gravity of stellar bodies does not change. (c) Light always travels in a straight line. (d) The speed of light is always the same.
- a.Distances among stellar bodies do not change.
- b.Gravity of stellar bodies does not change.
- c.Light always travels in a straight line.
- d.The speed of light is always the same. ✓
Science & Tech · UPSC 2021Consider the following statements in respect of India advanced satellite INSAT–4A: 1. INSAT-4A was launched in December, 2005 from New Mexico. 2. The European Commercial Launch Service Provider Arianespace was associated with the launch of INSAT-4A. 3. Tata-Sky; a digital cable service provider; is associated with DTH television broadcasting service from INSAT-4A. Which of the statements given above are correct? (a) 1, 2 and 3 (b) 1 and 2 only (c) 2 and 3 only (d) 1 and 3 only
- a.1, 2 and 3
- b.1 and 2 only
- c.2 and 3 only ✓
- d.1 and 3 only
Science & Tech · UPSC 2006With reference to 'Astrosat', the astronomical observatory launched by India, which of the following statements is/are correct? 1. Other than USA and Russia, India is the only country to have launched a similar observatory into space. 2. Astrosat is a 2000 kg satellite placed in an orbit at 1650 km above the surface of the Earth. Select the correct answer using the code given below. (a) 1 only (b) 2 only (c) Both 1 and 2 (d) Neither 1 nor 2
- a.1 only
- b.2 only
- c.Both 1 and 2
- d.Neither 1 nor 2 ✓
Science & Tech · UPSC 2016Match the names of outstanding Indian scientists given in List I with area of their specialized work given in List II and select the correct answer by using the codes given below the lists: List-I List-II A. Dr. Raja Ramanna 1. Plant chemistry B. Dr. M.S. Swaminathan 2. Nuclear physics C. Prof. U.R Rao 3. Thermodynamics & astrophysics D. Prof. Meghnad Saha 4. Space research 5. Agricultural science Codes: (a) A-3; B-5; C-2; D-1 (b) A-2; B-1; C-4; D-3 (c) A-2; B-5; C-4; D-3 (d) A-3; B-1; C-4; D-2
- a.A-3; B-5; C-2; D-1
- b.A-2; B-1; C-4; D-3
- c.A-2; B-5; C-4; D-3 ✓
- d.A-3; B-1; C-4; D-2
Science & Tech · UPSC 1998Between India and East Asia, the navigation-time and distance can be greatly reduced by which of the following? 1. Deepening the Malacca straits between Malaysia and Indonesia. 2. Opening a new canal across the Kra isthmus between the Gulf of Siam and Andaman Sea. Which of the statements given above is/are correct? (a) 1 only (b) 2 only (c) Both 1 and 2 (d) Neither 1 nor 2
- a.1 only
- b.2 only ✓
- c.Both 1 and 2
- d.Neither 1 nor 2
Geography · UPSC 2011In the context of modern scientific research, consider the following statements about 'IceCube', a particle detector located at South Pole, which was recently in the news: 1. It is the world's largest neutrino detector, encompassing a cubic kilometer of ice. 2. It is a powerful telescope to search for dark matter. 3. It is buried deep in the ice. Which of the statements given above is/are correct? (a) 1 only (b) 2 and 3 only (c) 1 and 3 only (d) 1, 2 and 3
- a.1 only
- b.2 and 3 only
- c.1 and 3 only
- d.1, 2 and 3 ✓
Science & Tech · UPSC 2015
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