The Sun will be closest to our planet today, giving an opportunity to astro-enthusiasts to carry out several experiments.
"At 5:53 am tomorrow (Perihelion Day), the Earth will be at its nearest point from the Sun. The distance at that time is 147 million km," Planetary Society of India General Secretary N Sri Raghunandan Kumar said on Wednesday.
Every January, the Earth is at perihelion, the closest from the Sun for the year and in July it is at aphelion, the farthest to the Sun for the year, he said.
The word perihelion comes from the Greek words "peri" (meaning "near") and "helios" (meaning "sun").
All planets, comets and asteroids in our solar system have elliptical orbits. Thus, they all have a closest and a farthest point from the Sun - a perihelion and an aphelion, he said.
Explaining the reason why the temperature does not rise on Perihelion Day even when the sunlight is more, Kumar said, "There are many reasons for it. Blame it on the tilt of the Earth's axis. Actually, our seasons are determined by the tilt of the Earth and not by how close the Earth is to the Sun. Sunlight raises the temperature of continents more than it does of the oceans."
Astro-ethusiasts are expected to gather at Jantar Mantar observatory and carry out experiments related to the distance between the Earth and the Sun.