Elliptical orbits & accurate Heliocentric periods
Aryabhata 499CE

Ellipse Equations
Mahavira 850CE

Uniform Mean planetary motion & instantaneous velocity
Bhaskara II 1150CE

Partial heliocentric model
Neelakanta 1501 CE

First unified model for inner & outer planets
Neelakantha https://twitter.com/Rainmaker1973/status/1128634556385517568

Correct Equation of center & calculation of eccentric orbits
Neelakantha

"The earth is not encircled by the orbits of Mercury & Venus."
-Parameshvara 1410CE

Angular motion of planets
Jyestadeva 1530CE

"The motion of planets varies each second"
Sankara Varier~1530CE

A comparison of sidereal periods obtained by Aryabhata and Neelakantha with modern values- A relentless thousand year effort without any fabrication or historical inconsistency.

Kepler discerned the elegant law, but it is now known that he didn't make the observations of orbital periods crucial for his theorems. He did not acknowledge sources-Arab or Kerala manuscripts the Jesuits brought for him. He was, ultimately, a plagiarist. https://www.nytimes.com/1990/01/23/science/after-400-years-a-challenge-to-kepler-he-fabricated-his-data-scholar-says.html

-In 1581 Matteo Ricci wrote to Jesuit Petri Maffei requiring assistance of an “intelligent Brahmin” to understand local time keeping(jyotisa)

(Reproduced in Documenta Indica XII 472-477)

-Just seven years later in 1588 Tycho Brahe published the EXACT same model of Neelakantha!

-After his master Tycho died in 1601, Kepler took/appropriated Tycho's data and worked with it for years.

-There is a letter from Johann Schreck in 1618, of astronomical observations intended for the benefit of Kepler

-In 1626 Kepler wrote to Jesuit mathematician Paul Guldin EXPLICITLY requesting astronomical observations from India.

“If I could only obtain soon the observations on the eclipse from India or from any other place…”
C. Baumgardt, Kepler: Life and Letters, Philosophical Library

Whats more-

-Jesuits accepted the Tychonic/Neelakantha model!

-Jesuit astronomers in China used it

-Prominent jesuits supported it- Christopher Clavius, Grienberger, Scheiner, Maelcote etc

-EVEN after Kepler, Jesuits CONTINUED to staunchly follow it for more than a century!

Look at the smooth series of events/letters above! One leading to another.

Tycho, Jesuits & Kerala astronomers using the SAME planetary model. HOW can this be a coincidence? Connecting 3 simple dots is an endeavor of common sense, not doing so is the height of double standards.

So what about the eclipse & orbital observations?

"Calculated positions are found to deviate from the observed. The shastras declare the observed to be true. Hence the twice born adept at astronomy must strive to obtain positions by observation"
-Parameshvara
Drgganita 1.2-4

Hear the words of a poor man who did decades of hard work only to have it pilfered and be forgotten by the world-

"The planets have been observed by me for fifty five years and they differ from positions derived from Parahita ganitam"
-Nilakantha quotes his teacher Paramesvara

"Since Saka 1315(AD 1393) I have observed a number of eclipses; all these occured at times prior to calculated ones. This necessitated corrections in the computational process"
-Paramesvara(Siddhantadipika)

"Paramesvara studied under Madhava, Rudra and Narayana. He understood the factors causing difference between calculated & observed positions. After verifying the work of earlier teachers though observations of eclipses & planetary conjunctions, he composed Drgganita"
-Neelakantha

Ref-
Indian planetary model and its revision by Nilakantha: K Ramasubramaniam
Eclipse observatons of Paramesvara: K Chandrahari
Yuktibhasa of Jyestadeva: KV Sharma
History of Indian Mathematics:C. S. Seshadri
Transmission of Calculus: CKR
Mathematics in India: M. D. Srinivas

To be continued..

Nilakantha's model, now known as 'Tychonic model'. It was literally ONE step away from Truth. The Aryabhata school had ALL pieces of the puzzle-Eccentric orbits, accurate periods, theory of rotation, voluminous observatory data etc. But the very LAST step was made by plagiarists.