Jan '24
Titan, also known as Saturn VI, is a prograde moon and is the largest natural satellite of the outer planet, Saturn. Is is also the second largest moon in the Solar System, just behind Ganymede,[1] one of the Galilean moons belonging to the outer planet, Jupiter. This however is the only moon known in the Solar System to have a dense atmosphere and is even believed to have surface water,[2] the only other body to have received this classification after our own Earth. Titan was discovered on March 25, 1655 by the Dutch astronomer Christiaan Huygens.[3][4] It was the sixth moon ever discovered, after Earth's Moon and the Galilean moons of Jupiter.
Discovery
Titan was discovered on March 25, 1655, by the Dutch astronomer Christiaan Huygens. Huygens was inspired by Galileo's discovery of Jupiter's four largest moons in 1610 and his improvements in telescope technology. Christiaan, with the help of his elder brother Constantijn Huygens Jr., began building telescopes around 1650 and was able to discover the first observed moon orbiting Saturn with one of the telescopes that they built.
Name
After Giovanni Domenico Cassini published his discoveries of four more moons of Saturn between 1673 and 1686, astronomers fell into the habit of referring to these and Titan as Saturn I through V (with Titan then in fourth position). The International Astronomical Union numbers Titan as Saturn VI.
The name Titan, and the names of all seven satellites of Saturn then known, came from John Herschel (son of William Herschel, discoverer of two other Saturnian moons, Mimas and Enceladus), in his 1847 publication Results of Astronomical Observations Made during the Years 1834, 5, 6, 7, 8, at the Cape of Good Hope. Numerous small moons have been discovered around Saturn since then. Saturnian moons are named after mythological giants. The name Titan comes from the Titans, a race of immortals in Greek mythology.
Formation
Since Saturn is so close to the Asteroid belt, it is believed Titan was a stray carbonaceous, or C-type, asteroid, the most populous of the asteroids in the Asteroid belt. Since they were (and still are) so populous, it is believed that many of these asteroids collided and created friction, which generated heat that fused these asteroids together. Once the later-to-be-named Titan became large enough - in fact large enough to maintain hydrostatic equilibrium - it could not collect any more and was pushed into deep space through other impacts. It is not completely clear how it escaped Jupiter's strong gravitational pull, but it is believed to be due to the amount of perturbation caused by the existing moons causing the gravitational pull to be slowed and keeping Titan from staying with Jupiter and instead traveling to Saturn, where it was soon captured.[citation needed]
Titan may have also been formed by a co-accretion. According from the source material, this would explain it’s high eccentricity and the icy materials of other of Saturn’s large moons.[5]
Surface Features
The surface of Titan can only be seen through high-tech radar telescopes, for it is completely covered by a dense, orange atmosphere. The surface of Titan is in many ways similar to Earth's, and in some places even Earth's moon. There have been reported sand dunes on Titan's surface, which are very similar to the likes of those seen on Earth - the lining of sand is, in comparison, similar to those of the Namib Desert. The Shangri-la of Titan, a long and extremely dark surface feature (referred to as a dark albedo feature), can be compared to the mares of Earth's moon. There are many faculae on the surface of Titan including the Shikoku Facula and the Sotra Facula.
| Geology of Titan | |
|---|---|
| Seas | Kraken • Ligeia • Punga |
| Lakes | Abaya • Bolsena • Feia • Hammar • Jingpo • Kivu • Koitere • Ladoga • Mackay • Müggel • Neagh • Ontario • Sionascaig • Sotonera • Albano |
| Rivers | Vid Flumina • Eliva Flumina |
| Dry lakes | Eyre • Ngami • Wotytchugga |
| High albedo | Adiri • Dilmun • Quivira • Tsegihi • Xanadu |
| Low albedo | Mezzoramia • Shangri-La |
| Arcus | Hotei Arcus |
| Craters | Menrva • Selk • Sinlap |
| Faculae | Santorini • Shikoku |
| Freta | Bayta • Hardin • Seldon • Trevize |
| Insulae | Mayda Insula |
| Large ringed features | Gaubonito |
| Maculae | Ganesa Macula |
| Montes | Doom Mons • Erebor Mons • Misty Montes |
| Paterae | Sotra Patera |
| Plains and Regions | Arrakis Planitia • Tui Regio |
| Virgae | Perkunas Virgae |
Atmosphere
The atmosphere of Titan is the only fully developed atmosphere of any moon in the Solar System, and is also the densest of any moon. The atmosphere's presence was first discovered by Spanish astronomer Josep Comas Solà in 1903. The atmosphere is composed of 98.4% nitrogen, which makes it ~1.2 times more massive than Earth's atmosphere. The rest of the atmosphere is composed of trace gases including ethane, propane, carbon dioxide, and argon.[6]
Composition
The composition of Titan makes it more massive than any other moon belonging to Saturn (aka the Saturnian moons). The uppermost layer is the crust which is mostly covered in water-ice. There's an ocean located just beneath the ice. Oceans and lakes are found on the crust. Titan is so cold that the gas changes state and becomes a liquid. Under the crust is the upper mantle. It's unknown what is under the upper mantle.
At the south pole of Titan is a permanent hurricane that continues to expand today. It pushes matter into the atmosphere, making itself denser as it expands. Since clouds typically cover about 0.9% of Titan's surface, this hurricane is unique, for it covers quite a distance. Titan might have life, or it might not - but it does have rivers and rocks.
The night side of Titan, taken by Voyager.
Structure
Titan’s internal structure isn’t entirely known, but one model based on data from the Cassini-Huygens mission suggests Titan has five primary layers. The innermost layer is a core of rock (specifically, water-bearing silicate rock) about 2,500 miles (4,000 kilometers) in diameter. Surrounding the core is a shell of water ice—a special type called ice-VI that is only found at extremely high-pressures. The high-pressure ice is surrounded by a layer of salty liquid water, on top of which sits an outer crust of water ice. This surface is coated with organic molecules that have rained or otherwise settled out of the atmosphere in the form of sands and liquids. The surface is hugged by a dense atmosphere.
Exploration
Titan was a mysterious moon before it was first explored by Pioneer 11 and Voyager 1. Pioneer 11 data showed that Titan was probably too cold to support life, and Voyager 1 was able to discoverer key details about the atmosphere, like its density. If Voyager 1 didn’t target Titan, it is possible it could have gone to Pluto.
Cassini-Huygens visited Saturn in 2004, and started orbiting around Titan, and landed a probe on Titan, called Huygens. Huygens lasted a few hours on the surface, observing and conducting research. Cassini also made multiple flybys of Titan during its main and extended missions.
Flybys
| Probe | Closest Approach | Date |
|---|---|---|
| Pioneer 11 | 362,962 km | September 2, 1979 |
| Voyager 1 | 6,490 km | November 11, 1980 |
| Cassini-Huygens | Multiple Flybys | Multiple Flybys |
Landers
| Name | Date Landed |
|---|---|
| Huygens titan Lander | January 14, 2005 |
Atmospheric Composition
Structure: Atmosphere * Upper atmosphere * Thick tholin haze * Lower atmosphere Normal ice (1h) Liquid water ocean Ice-six (tetragonal crystals) Hydrous silicate core
| Molecule | Symbol | % (stratosphere) | % (lower troposphere) |
| Nitrogen | N2 | 98.4 | 95.0
97 |
| Methane | CH4 | 1.4 | 4.9
2.7±0.1 |
| Hydrogen | H2 | 0.2 | 0.1-0.2 |
Gallery
Bibliography
- ↑ https://web.archive.org/web/20200212021254/https://pdfs.semanticscholar.org/7ec3/29458f5dabfa6c370476df8236779941f93f.pdf
- ↑ Robert Brown; Jean Pierre Lebreton; Hunter Waite, eds. (2009). Titan from Cassini-Huygens. Springer Science & Business Media. p. 69.ISBN
- ↑ "Lifting Titan's Veil" (PDF). Cambridge. p. 4. Archived from the original (pdf) on February 22, 2005.
- ↑ "Titan". Astronomy Picture of the Day. NASA. Archived from the original on March 27, 2005.
- ↑ https://www.spacedaily.com/reports/Giant_impact_scenario_may_explain_the_unusual_moons_of_Saturn_999.html
- ↑ https://web.archive.org/web/20051202030828/https://saturn.jpl.nasa.gov/news/features/saturn-story/moons.cfm
| Moons of Saturn | |
|---|---|
| Ring Shepherds | S/2009 S 1 • Pan • Daphnis • Atlas • Prometheus • Pandora |
| Co-orbitals | Janus • Epimetheus |
| G Ring | Aegaeon |
| Alkyonides | Methone • Pallene • Anthe |
| Inner Large Moons | Mimas • Enceladus • Tethys • (Telesto • Calypso) • Dione • (Helene • Polydeuces) |
| Outer Large Moons | Rhea • Titan • Hyperion • Iapetus |
| Inuit | Kiviuq • Paaliaq • Siarnaq • Ijiraq • S/2005 S 4 • S/2019 S 1 • S/2020 S 1 • Tarqeq • S/2004 S 31 • S/2019 S 14 • S/2020 S 3 • S/2019 S 6 |
| Gallic | Albiorix • Bebhionn • S/2007 S 8 • S/2004 S 29 • Erriapus • Tarvos • S/2020 S 4 |
| Norse | Phoebe • S/2006 S 20 • S/2006 S 9 • Skathi • S/2007 S 5 • S/2007 S 7 • S/2007 S 2 • S/2004 S 37 • S/2004 S 47 • S/2004 S 40 • S/2019 S 2 • S/2019 S 3 • S/2020 S 7 • Skoll • S/2020 S 2 • S/2019 S 4 • S/2004 S 41 • S/2004 S 42 • Hyrrokkin • Greip • S/2004 S 13 • S/2007 S 6 • Mundilfari • S/2006 S 1 • S/2004 S 43 • S/2006 S 10 • S/2019 S 5 • Gridr • Bergelmir • Jarnsaxa • Narvi • Suttungr • S/2007 S 3 • S/2004 S 44 • S/2004 S 45 • Hati • S/2004 S 17 • S/2006 S 11 • S/2004 S 12 • Eggther • S/2006 S 13 • S/2007 S 9 • S/2019 S 7 • S/2019 S 8 • Farbauti • Thrymr • Bestla • S/2019 S 9 • S/2004 S 46 • Angrboda • S/2019 S 11 • Aegir • Beli • S/2019 S 10 • S/2019 S 12 • Gerd • S/2019 S 13 • S/2006 S 14 • Gunnlod • S/2019 S 15 • S/2020 S 6 • S/2004 S 7 • S/2006 S 3 • S/2005 S 5 • Skrymir • S/2006 S 16 • S/2006 S 15 • S/2004 S 28 • S/2020 S 8 • Alvaldi • Kari • S/2004 S 48 • Geirrod • Fenrir • S/2004 S 50 • S/2006 S 17 • S/2004 S 49 • S/2019 S 17 • Surtur • S/2006 S 18 • Loge • Ymir • S/2019 S 19 • S/2004 S 21 • S/2019 S 18 • S/2004 S 39 • S/2019 S 16 • S/2004 S 53 • S/2004 S 36 • Thiazzi • S/2019 S 20 • S/2006 S 19 • S/2004 S 26 • Fornjot • S/2004 S 51 • S/2020 S 10 • S/2020 S 9 • S/2004 S 34 • S/2019 S 21 • S/2004 S 52
|
| Outlier Prograde Satellites | S/2006 S 12 • S/2004 S 24 |
| Spurious Moons | Chiron • Themis • S/2004 S 6 • S/2004 S 4 • S/2004 S 3 • Peggy |