School students in the national capital marked vernal equinox or the first day of spring by measuring the dimensions of Earth at the astronomical observatory Jantar Mantar.
SPACE, an organisation working towards development of science and astro-tourism in India, celebrated the day with school students and general public under 'Project Paridhi' at the ancient sun dial.
About 55 participants from 11 school replicated and took actual measurements of the shadows made by the sun to find the sun's angle and estimate the circumference of the Earth.
"This project was initiated by SPACE four years ago with the intention to increase awareness among Indians that science can be done without any complicated equipment," an official of SPACE said.
"With the help of this project conducted at our heritage site Jantar Mantar, SPACE has highlighted that such Indian monuments can be used as tools to demonstrate and get the common man interested in science," the official added.
An equinox occurs twice a year (around March 20 and September 22), when the plane of the Earth's equator passes the centre of the sun.
The name "equinox" is derived from the Latin aequus (equal) and nox (night), because around the equinox, night and day are about equal length as the sun shines directly on the equator.
"Session was well conducted by SPACE group members. The working of various yantras was well explained by SPACE educators. This is nice way to popularise hands-on science and promote learning in an informal atmosphere as a group activity," said V R Geetha, a student coordinator from Bal Bharti Public School.
"The session at Jantar Mantar was quite interesting. There was a lot more to explore at the location," said Aditi Sharma, a student coordinator from Sachdeva Public School, Rohini. "The information that I gathered was quite thrilling. The overall session was knowledgeable," she said.