Humans make first observations of the skies.

~800 BC

Assyrian and Babylonian astronomical observations are recorded.

~650 BC
Earliest known recorded observations of Saturn are made in Mesopotamia.

~300 BC
Mythological view of Saturn as a god, by the Romans.

~150 AD
Hellenistic astronomer Claudius Ptolemaeus (Ptolemy) makes observations of Saturn. From these, he makes predictions of Saturn's future positions in sky.

700-800 AD 
Islamic astronomers working in Damascus and Baghdad observe and record Saturn's position. They find that Ptolemy's predictions were wrong.

Galileo notes the "triple planet" Saturn with his telescope.

Galileo observes Saturn again. This time, it appears as a single golden-hued disc.

8 June 1625
Gian Domenico Cassini was born in Perinaldo, Italy.

14 Apr 1629
Christiaan Huygens was born into a prominent Dutch family. He received the best education possible, including training by Descartes.

Cassini invited to work at observatory of Marquis Cornelio Malvasia, near Bologna, where he worked till going to France.

Cassini was elected chair of astronomy at the University of Bologna.

Huygens published first work - Theoremata de quadratura hyperboles, ellypsis et circuli - a geometrical work.

Cassini designed and had constructed a new and larger meridian for the church of San Petronio of Bologna. This helped to establish his reputation.

Huygens visits Paris to make contacts with lens makers. His successful aim for this trip was to improve the technique and design of his own lenses.

March 1655
Huygens made the discovers that would make him famous, including the discovery of Titan.

Huygens published De Saturni luna observation nova, to report his discoveries.

Cassini published Specimen observationum Bononiensium qaue novissime in D. Petronji templo ad astronomiae novae constitutionem haberi cepere.

Cassini presented a planetary system model in agreement with Tycho Brahe. Meanwhile, Huygens published Systema Saturnia. It contained more observations of Saturn and its "arms". He hypothesised that the "arms" were a ring surrounding the planet.

Jean-Baptist Colbert recruited Huygens as a founding member of the Academie Royale des Science.

July 1664
In his first discovery with a telescope, Cassini detected the shadow of Jupiter's satellites and studied their revolutions. He was able to calculate the period of Jupiter to be 9h 56m, only one minute off of the currently accepted 9h 55m.

Colbert offered Cassini membership in the Academie Royale des Science as a regular correspondent.

25 Feb 1669
Cassini departs for Paris to aid in the establishment of an observatory. This was the end of his life in Italy.

Sept 1671
Cassini discovered Japetus, the second satellite of Saturn.

Cassini discovered Rhea, the third satellite of Saturn.

Cassini discovered the rings of Saturn by observing a band of shadow on the planet's surface. He also discovered that the ring was divided in two smaller rings by, what is now known as, "Cassini's Division". He hypothesised that the rings were composed of a large number of individual corpuscles, an idea that has been proven correct.

21 Mar 1684
Cassini observed two more satellites of Saturn - Tethys and Dione.

Huygens died in The Hague.

14 Sept 1712
Cassini died in Paris.

Herschel discovers two satellites of Saturn - Mimas and Enceladus. He also notes the thinness of the rings.

Bond and Lassel discover the satellite Hyperion.

Bond, Bond and Daws discover inner ring.

Maxwell proves that the rings are not solid.

Keeler measures ring velocities.

Pickering discovers satellite Phoebe.

Wildt discovers methane and ammonia on Saturn.

Kuiper discovers methane and ammonia on Titan.

Pioneer 11 flies past Saturn.

Voyager 1 encounters Saturn.

Voyager 2 encounters Saturn.

Hubble Space Telescope's Wild Field and Planetary Camera images Saturn for the first time.

Hubble's Wide Field and Planetary Camera 2 images ring plane crossing.

Hubble images seen here were taken as the ring goes for just past edge-on (bottom) to fully open (top) - see background images.

The formal beginning of the Cassini-Huygens Space Mission was a Joint Working Group of the ESA and the NAS. European scientist proposed a Saturn orbiter and Titan probe mission.

US Solar System Exploration Committee recommended NASA include a Titan probe and radar mapper in core program.

Joint NASA/ESA assessment of Saturn probe and Titan probe was completed.

ESAs Science Program Committee approved Cassini for Phase A study. Conditional start in 1987.

Titan probe was renamed Huygens by ESA, as part of Horizon 2000 space science program.

NASA developing and designing Mariner Mark II spacecraft program. Cassini-Huygens Mission was chosen as one of first missions within the Mariner Mark II program.

Funding for Cassini was approved by the US Congress. NASA and ESA announced opportunity for scientists to propose scientific investigations for the mission.

Funding cap was placed on Mariner Mark II program, that effectively ended the program. This also forced the Cassini program to be restructed.

15 Oct 1997
Cassini-Huygens launched.

26 Apr 1998
Gravity Assist past Venus at 284k (176 miles).

24 June 1999
Gravity Assist past Venus at 600k (370 miles).

18 Aug 1999
Gravity Assist past Earth at 1,171k (727 miles).

30 Dec 2000
Gravity Assist past Jupiter at 9,723,890k (6,042,145 miles).

1 July 2004
Cassini-Huygens arrived at Saturn.

26 Oct 2004
Cassini-Huygens passes Titan for first time at 1,200k (746 miles).

25 Dec 2004
Huygens probe is released from Cassini spacecraft to begin a 21-day journey to the surface of Titan.

14 Jan 2005
Huygens probe descends to surface of Titan. Becomes first man-made object to land on a planet in the outer solar system.

15 Feb 2005
Cassini spacecraft has first of six encounters with Titain during year, they range in altitude from 1,025k (637 miles) to 60,000k (37,290 miles).

Cassini spacecraft continues to orbit Saturn and studying the moons, mainly Titan, with which it has 36 encounters during that time.

30 June2008
End of Prime Mission.

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