Hanuman Chalisa holds great importance and is very revered and sacred not because it is a praise of Lord Hanuman but also because Tulsi Das has written some of the great life lessons in it. Of all the greatness Hanuman Chalisa gave certain facts even before its scientific discoveries.
One of such engaging facts is the distance between the sun and the earth. The 18th verse in the Hanuman Chalisa states that:
जुग सहस्त्र जोजन पर भानु,
लील्यो ताहि मधुर फल जानू
In English –
Juga sahastra jojan par bhaanu |
Leelyo taahi madhur phal jaanu |
The first line essentially means that:
juga means the sum of Four Yugas (1 complete Mahayuga) with a unit in divine years.
Satiyuga= 4800 divine years
Tretayuga=3600 divine years
Dwaparyuga=2400 divine years
Kaliyuga=1200 divine years
So 1 juga= 12000 years
Now next is sahastra (सहस्त्र) is common Sanskrit word meaning “1000”
Next is jojan also know as Yojan that equals to 8 miles…!!
let us calculate the distance of the sun from earth
Juga X Sahastra X jojan (in miles) = 12000 X 1000 X 8 = 9,60,00,000 miles
Now 1 mile= 1.6km
So 9,60,00,000 miles= 9,60,00,000 X 1.6 km = 15,36,00,000km.
The next sentence refers to the Lila of Hanuman as a kid where Hanuman assumed the Sun (भानु) to be a fruit and left from earth, to get hold of the sun to eat it.
Find the story here: http://www.lordhanuman.info/how-and-when-was-the-great-hanuman-chalisa-written-your-answer-is-right-here/
Hence it is certain that the 18th verse of Hanuman Chalisa gives the estimation of the earth’s distance from the sun.
Years later, in According to Records, For the first time in 1672, Jean Richer and Giovanni Domenico Cassini measured the distance between Earth and Sun as 22,000 times of Earth Radii.( Earth’s Radius is 6,371 Kms).
i.e 22000 * 6371 km = 140,162,000 km (140 Million Kms).
Today estimated distance by NASA is approximately 15,0000000 km which is close to above.