Leaving aside the controversies surrounding the dating of the Rig Veda, there is universal agreement on the fact that the wisdom contained therein is highly sacrosanct. Max Mueller, who had the dubious distinction of assigning the date as 1200 BC, is believed to have said, "Whatever maybe the date of the Vedic hymns, whether 1500 or 15000 BC, they have their own unique place in the literature of the world" 1. Several authors have propounded the case that the Vedas are encoded with scientific insights and riddles unbeknownst to the common man. The Vedic seers were so highly advanced that they deliberately camouflaged cosmic mysteries in their beautiful poems! This in many respects parallels what the Mayans are believed to have done via their myths and allegories. They were sky watchers who kept accurate record of the passage of time with respect to the celestial blueprint. 2 

Some of the more interesting concepts of astronomy encoded in the Vedas are nicely discussed by B. G. Sidharth 3. For instance, the lunar calendar followed by many different cultures around the world, is time and again mentioned in the Vedas. The concepts of synodic and sidereal motion were well known to the Rig Vedic composers. Synodic motion (time between 2 full moons) of the moon is 29.5306 days which equals 354 days in a year, and falls short of the solar year by 11 days. Rig Veda 1.25-8 says that Varuna knows the twelve Moons. He also knows the Moon of later birth. This is in reference to the intercalated month added periodically to reconcile the lunar year with the solar year! Thus 1 month (intercalary) has to be added to 3 lunar years or 3 months have to be added to 8 years 4. The lunar calendar is practical in terms of keeping track of time and certainly was followed by many ancient cultures! 

Sidereal motion (1 complete revolution around the earth) of the moon takes 27.3217 days. Thus along the path of the moon it traverses 27 nakshatras or group of stars. Here Sidharth brings in the myth that Daksha had 28 daughters and the Moon spends about one day in each nakshatra and takes a little over 27 days to complete its synodic cycle. Hence one nakshatra had to go and Daksha married off one of his daughters to Siva.  

A further significance of the number 27 can be seen in a circle drawn inside a square touching its sides. The circle is divided into twelve equal parts (12 x 30 = 360). They are named after the common zodiac signs for convenience. Then the circle is divided into 27 equal parts of 13 degrees 20 minutes (13^o 20' x 27 = 3600) accommodating 27 stars per asterism. 5

Interestingly this combination of 13 and 20 is found in the Mayan calendar, referred to as the Tzolkin.! The Mayans also had a 365 day calendar, known as the Haab which intermeshed with the Tzolkin. 

The most striking feature appears to be identification of the Precession of the Equinoxes, which simply put, alters the position of the star in the sky due to the spinning motion of the Earth, i.e. the celestial north Pole does not point towards the same star after a given period of time due to the wobble of the earth as it spins on its axis. The precession of the equinox appears to be the underlying theme in Giorgio de Santillana and Hertha von Dechend's masterpiece, Hamlet's mill, as being the encoded message in myths amongst many cultures. 6 Due to precession, the vernal equinox moves along the ecliptic by 1' in approximately 72 years. Coincidentally, the number of temples built around Angkor Wat is 72! The Chatur-yuga, 4,320,000 years is related to the precessional cycle, 25,867 years corresponding to a precession of 50.1 arc-seconds per year. This is amazingly close to the normally accepted value of 50.2 arc-seconds for the precessional constant.

Kak indicates that the distance from the Earth to the Sun is 10 times the diameter of the Sun, while the distance from Earth to the Moon is 108 times the diameter of the Moon. 7 This could be the reasoning behind the appearance of the number 108 in the Vedas and Upanishads. Interestingly 1¹x 2² x 3³ = 108, and is the number of beads in a rosary and also the number of stone figures leading up to the temple in Angkor. The number of verses in the Rig Veda total 10,800. The total number of bricks in a Vedic fire altar is also 10,800!

To paraphrase Santillana & Dechend , 'Again when one finds numbers like 108, reappearing under several multiples in the Vedas, in the temples of Angkor, in Babylon, in Heraclitus' dark utterances, and also in the Norse Valhalla it is not an accident. 

Sidharth also points out that 1¹x 2²x 3³ x4⁴x5⁵ = 86,400,000. Now in 1 day you have 86,400 seconds or 43,200 seconds in half a day (the Kalpa is 4,320,000,000). 

A verse from the Norse Poem 8, 'The lay of Grimnir' (Grimnismal 24) goes like this

Five hundred and forty doors 
Are built into bright Valhalla
Eight hundred warriors through one door 
Shall go out to fight with Fenris.

This would make it 432,000! This is also equal to the number of verses in the Rig-Veda (10,800) times the pada or lines (40). 

Bjorn Merker posits that the seven sages of the Vedas are Ursa Major, which may also figure as the seven-wheeled chariot with seven riders and horses of Rig Veda 1.164.3, and possibly even as the seven half-embryos of 1.164.36, which "themselves surrounded, surround it on all sides." As Ursa Major they would be surrounded by stars, and surround the pole star by going around it. 9 

This is a reflection of just a miniscule amount of information encoded in the infinite Brahman.

Acknowledgement
The translation from the Rig Veda at the beginning of this article is taken from W. Doniger, The Rig Veda: An anthology, Penguin Books, 1981