Bengaluru to experience Zero Shadow Day today
Bengaluru: Bengaluru will experience Zero Shadow Day on Thursday at exactly 12.17 pm. Objects will cast a shadow exactly downward, causing objects on the ground to have no visible shadow..According to astronomers at the Indian Institute of Astrophysics, Bengaluru (IIA), this phenomenon occurs twice a year, once around April 24 or 25 and a second time around August 18..At local noon, the sun will be at its zenith (highest point in the sky), but this highest point is not exactly overhead on most days. The sun transits north or south of it due to the 23.5-degree tilt of the Earth's axis of rotation with respect to the plane of Earth's revolution around the sun. On Zero Shadow Days, however, the sun is directly overhead, causing vertical objects to cast no visible shadows..When the sun transits directly above the Tropic of Cancer (+23.5° latitude), it is called the summer solstice (around June 21), and when the sun transits directly above the Tropic of Capricorn (-23.5° latitude), it is called the winter solstice (around December 22)..World Psycho-Oncology Day: Experts demand psychosocial care for cancer patients .The sun transits across the equator twice a year on days called equinoxes. The arc made by the sun in the sky changes throughout the year. The arc moves southwards starting on the summer solstice and passes over the equator around September 23 (autumnal equinox), subsequently transiting directly over the Tropic of Capricorn during the winter solstice. After this, the arc makes its journey northward. The arc's transit between one tropic and the other takes six months..Therefore, for people who live in the tropics (+23.5° to -23.5° latitude), the sun passes directly overhead twice a year — once when the arc transits northward and once when the arc transits southward..Zero Shadow Days occur on different days for different cities when the sun transits directly overhead based on their latitude..Activities planned at IIA.Talk: 10 am.Hands-on activities: 11.30 am.Computation session: 12.30 pm.IIA is coordinating with a team in Bhopal to compute the diameter of the Earth through shadow length measurement.
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
New Indian Express
7 hours ago
- New Indian Express
Moon-Mars conjunction to dazzle skywatchers
BENGALURU: Skywatchers are in for a celestial event in the early hours of June 30, when the Moon and Mars will appear unusually close to each other in what astronomers call a conjunction. While such alignments between the Moon and planets occur regularly, this particular one stands out for its timing as Mars edges closer to its opposition later this year, gradually becoming brighter in the night sky. In this phenomena, in the pre-dawn hours, observers with clear skies may witness a slender crescent Moon paired with the reddish glow of Mars, both positioned in the same region of the sky — separated by just about 3 degrees. Although the two bodies are actually million of kilometres apart, they will appear side by side from Earth due to a quirk of orbital alignment. Despite the event's potential, seasoned skywatchers and experts caution that those in Bengaluru and much of India may miss out due to monsoon conditions. 'Cloud cover and moisture-laden air during the early mornings can obscure the eastern horizon where the Moon and Mars will rise,' said an official from the Indian Institute of Astrophysics (IIA), adding that even a thin veil of clouds can completely wash out the view of the crescent Moon.' A conjunction happens when two celestial bodies appear to align in the sky from Earth's perspective. In this case, the Moon, which moves faster along its orbit, catches up and passes near Mars in the background sky. Such close approaches often go unnoticed, but when they involve bright planets and occur during dark-sky hours - like this one - they can create dramatic views. 'This conjunction is unique because of the geometry involved — the thin waning crescent Moon rising shortly before dawn, with Mars just above it, makes for a particularly delicate arrangement,' an official from the IIA said, adding that such well-positioned conjunctions are infrequent. While Moon-planet conjunctions are common, most are either obscured by daylight, occur too close to the horizon, or involve planets that are faint or too close to the Sun. What makes the June 30 event rare is a combination of factors - Mars is steadily brightening, the Moon is in a delicate crescent phase, and the timing - just before sunrise - provides a dark enough sky for good contrast, a senior official from the Jawaharlal Nehru Planetarium explained.
The Hindu
16 hours ago
- The Hindu
IIA researchers use commercial dish TV antennas to measure Sun's magnetic field
A team of scientists and engineers from the Indian Institute of Astrophysics (IIA) radio astronomy group has used a novel technique to measure the Sun's magnetic field using commercial dish TV antennas. The technique involves measuring the magnetic field in the solar chromosphere, the region between the Sun's photosphere and corona, using the commercial dish TV antennas. The team demonstrated the technique recently. According to the team, the antennas operate at a frequency of 11.2 GHz, which is in the radio astronomy band of the electromagnetic spectrum. They said that this novel and unique effort has paved the way for regular measurement of the Sun's magnetic field from its surface to the outer layers of its atmosphere. 'Measurement of the magnetic field in the solar chromosphere is a key link to establish the connection between the Sun's surface and its corona from where the space weather disturbances originate. We are glad to have established a comparatively low-cost facility in the institute's Radio Astronomy Field Station in Gauribidanur for this purpose,' R. Ramesh, senior IIA professor and in charge of the Gauribidanur radio astronomy field station, told The Hindu. Spurring other experiments Prof. Ramesh said that the affordable set-up is expected to spur the educational institutions in the country to establish a similar facility on their campus, thereby paving the way for affordable astronomy that can provide valuable scientific quality data in addition to being a test bed to develop new technology within the country. Students from BMS College of Engineering, Bengaluru, and Amrita Vishwa Vidyapeetam, Bengaluru Campus, were involved in the set-up in Gauribidanur as part of their academic project work. He said the set-up will cost ₹20 lakh. 'This is a paltry sum compared to the budget required to establish a similar facility for measuring the Sun's magnetic field via conventional optical astronomy techniques, either from ground or space platforms,' he added.
Hindustan Times
18-06-2025
- Hindustan Times
Sitharaman visits project site for infra-red observatory in Ladakh
Union finance minister Nirmala Sitharaman, on Tuesday, visited the project site for national large solar telescope (NLST) near strategic Pangong Lake in Meral area of Ladakh. The finance minister also took to X and related the information. 'Smt @nsitharaman visits the project site for National Large Solar Telescope (NLST), located near the Pangong lake in Merak, Ladakh at an altitude of around 4200m', she wrote on X. NLST is a proposed ground based 2-m class optical and near infra-red (IR) observational facility and the site provides significant periods of coronagraphic skies (high transparency), it read further Dr Annapurni Subramaniam, Director of Indian Institute of Astrophysics (IIA) was also present. On Sunday, Sitharaman had laid the foundation stone for a mini planetarium and Astro Globe at the Hanle Dark Sky Reserve in the Changthang region of the strategic region. The initiative, sanctioned under the special development package comes at an estimated cost of ₹276.65 lakh and aims to promote scientific education, astro-tourism, stargazing, night sky programs, and generate local employment, said an official spokesperson. At the Bhabha Atomic Research Centre's Major Atmospheric Cherenkov Experiment (MACE) Telescope facility in Hanle, Prof Annapurni Subramaniam, Director of the Indian Institute of Astrophysics (IIA), and Dr K.K. Yadav from the Astrophysical Sciences Division, BARC presented the telescope's current achievements and future plans. Applauding the efforts of IIA and the local community, Sitharaman remarked, 'This project symbolizes a collaborative spirit between the scientific and public community, a true matter of national pride.' She urged the development of programs tailored for the common public to spark interest in astrophysics through hands-on learning and proactively putting out content generated through these scientific centres. During her visit to Hanle, Sitharaman engaged with delegations of anganwadi workers, contractor associations, and BJP members from Nyoma, attentively listening to their concerns. At Rongo, she visited an animal husbandry site where she met with mostly female pashmina goat and yak herders. She distributed goat-shearing machines to support their livelihood. As part of the Dharti Aaba Janbhagidari Abhiyan, Sitharaman interacted with campaign beneficiaries. She also presented a ₹50 lakh cheque to Nyoma nomads under SBI's Corporate Social Responsibility initiative. The departments of sheep and animal husbandry hosted a live demonstration of the nomadic lifestyle. The department of social and tribal welfare showcased a mobile Anganwadi centre for nomadic children and displayed millet-based dishes prepared within the centre.
