CLOUD WORLD: MISSION to TITAN
by Michael Hammerschlag
updated Jan '07
JPL's Torrence Johnson on TiTAN landing (realaudio) 4-27-06 Brown U 7:16min on lack of surface liquids, methane-ethane properties, acetylene icebergs; LAKES FOUND!!!! Jan 2007 Pic at bottom; HI-RES LANDING MOVIE -spectacular!
HAMMERNEWS.com LANDS SUCCESSFULLY- pics! 7:40am
Early Friday (Jan 14, 2005) morning (4:50am EST), the last grand space mission –the 11 year $3 billion Cassini mission to Saturn, dropped a landing probe into the most earthlike atmosphere in the Solar System, the heavy clouds of massive moon Titan. Titan is, with Ganymede, the largest moon in the solar system*- at 3200 mi. diameter, bigger than planets Mercury or Pluto, and possessed with an amazing primeval blanket of supercooled air- 94+ % nitrogen (Earth is 79%), 2-6% methane, and the remainder a dirty orange smog of complex organics. Though having only 1/7th the gravity of Earth, Titan’s atmosphere is 1.5 times Earth’s pressure at the surface (equal to 20ft underwater) and 4½ times as dense, and extends out 120 miles (compared to Earth’s 30 miles). But unlike Earth, the distant frigid world, which gets only 1% of the sunlight of Earth, is a bone chilling –178C (-290F, 95K), where the methane and ethane would be liquid, and very close to solid- leading to speculation of lakes, oceans, and volcanoes of methane or ethane. Radar pics of the surface from the flybys of Cassini didn’t seem to show any such thing- they’ve only shot a small portion of the surface, but Huygens pics seem to show a methane sea, shore, and shoals. The only other solid body in the solar system with an appreciable atmosphere, Venus, has sulfuric acid clouds in CO2 at 100 times Earth's pressure and hellish 700° temperatures.surface of Titan 8:00am 1/14/2005
Huygens Titan pic fm 10 mi 1/14
Although the extreme cold would prevent life, liquid organics react much better than gases or solids, which are too unconcentrated or immobile, so Titan is an organic cauldron with compounds and gases thought to be similar to the dawn life on Earth- 4 billion years ago. And it is an ice world: much of the moon is believed to be composed of a 50/50 (water) ice/rock mixture- the density is only 1.88 times that of water (Earth is 5.5, surface rocks about 2.8, and gas giant Saturn is only .7 and would float in water), so there may be liquid water at depths to combine the complex snow of organic compounds into amino acids and proteins.. the building blocks of DNA. “Methane is irreversibly destroyed by solar UV radiation at high altitudes in 50 million years,” says Johns Hopkins Univ. Cassini-Huygens scientist Darrell Strobel from Darmstadt, Germany, the European Space Agency’s Operation Center. (They built the Huygens) “If this process continued over the age of the solar system, that’s enough to create 200-300 meters (layer) of complex hydrocarbons (on the surface).” Cassini scientists have found diacetylene and benzene hundreds of miles out in the atmosphere, amazing for such large molecules, and can see high white cirrus like clouds. Titan keeps one side locked to its magnificent master Saturn and its spectacular rings (which is now the closest it gets to Earth-visible all night at opposition) and whips around it in 16 days at about 3 times the distance that the Moon is from Earth.
Titan methane lakes? fm 5 mi.1/14
Titan methane lakes? fm 5 mi.1/14
The discus shaped 9 ft. 700lb. shell of the Huygens probe, released Christmas Eve, will slam into the Titanic atmosphere at about 13,500mph (3¾ miles a second) at about 170 miles altitude, heat to 2700 degrees on the shuttle-like ceramic tiles, and violently slow (14G deceleration) to about 900 mph at 90 miles up, where a little 8ft parachute yanks off the top half of the discus and deploys a 27ft parachute. “Titan's atmosphere is much more extended (4 times farther for equivalent pressure) than Earth’s because of the low gravity,” says Strobel. At 65 miles, that parachute is cut away and a smaller 10ft parachute deploys, so that the lithium batteries won’t be used up in the 2 hour 20min drop to the surface. A gas chromatograph, and spectrometer will heat and analyze the atmospheric gases at many altitudes and cameras will madly blast away at the surface. 35 Plutonium pellet heaters keep the craft from freezing blind in the bitter alien skies, and Doppler-shift radio analysis may determine winds [over 310mph measured!] and rocking (inc. of a liquid landing). Radar and acoustic receptors will measure the distance to the surface, the speed of sound, the roughness and constitution of the surface (and depth?). clouds of Titan fm 750 mi Nov '04
rings in false color
Just above the surface brilliant lights are turned on for the spectrograph and cameras, as the discus crunches onto the surface at 12 ft/sec (15mph), blasting up data to the mother ship. The heated gas trap will vaporize the solid or liquid surface and analyze it with the spectrometer/chromatograph. The JPL/ESA scientists dream it might land in a methane and/or ethane lake (it floats), but admit that would quickly freeze it and damage components; hopefully many sensors would first measure the density, temperature, waves, electrical, optical, acoustic, and thermal characteristics. Even if it works perfectly, the surface life is only expected to be 2¼ hours [lasted longer], when Cassini, about 40,000 miles away, will disappear over the Titanic horizon; but Cassini will make over 40 more passes by it, as close as 590 miles.
The 6.3 ton (with fuel) Cassini, launched
in 1997, only could reach Saturn by using
convoluted gravity assists- twice from Venus,
once from earth, and once from Jupiter; so
it had to be built to take the furnace heat
inside Venus’s orbit as well as the billion
mile cold of Saturn. At the time, I thought
it was very risky- they shielded it from the sun by hiding
behind the dish antenna (the Galileo main
dish was crippled on its Jupiter mission).
Arriving at Saturn on June 30th, Cassini
had to twice pass through the hazardous bands
of ice and rock in the rings. Everything
has gone tremendously well: on New Years
Day, they flew by the bizarre moon of Iapetus,
one fourth of which looks like it is covered
with shiny asphalt, the rest light. The mission
should function till at least 2008, with
69 fly bys of the moons, and extensive photography
and analysis of Saturn’s moons, clouds, gases,
winds, magnetic fields, and unique rings;
and help to understand the dawn of life. Radar image of Titan surface fm Cassini
Started in 1983- this is the culmination of a quarter century effort for the cheering scientists in Darmstadt and Pasadena.
shore of methane lake with shoals? wider shot below
Jan 14 11:30pm The first Huygens picture from 16 km (~10mi) shows channels that they claim are rivers, but to me it looks like it could be the tops of clouds. Incredible, the pic of rocks- but surprising how much one rockfield looks like any other (Mars). The 5 mile high shot shows a jumble with what looks like patches of liquid, and the wide composite is a lake with whitecaps- the closeup even shows shoals. They lost one radio channel from the Huygens, but every bit of data was recieved from the other- with the 8 time redundant transmission, into the twin 2.2 gig hard drives on the Cassini- top of the line in 1996.
Jan 21 ESA Bulletin: "These channels merge into river systems running into lakebeds featuring offshore 'islands' and 'shoals' remarkably similar to those on Earth...However, the fluid involved is methane, a simple organic compound that can exist as a liquid or gas at Titan's sub-170°C temperatures, rather than water as on Earth.... Heat generated by Huygens warmed the soil beneath the probe and both the GCMS and SSP detected bursts of methane gas boiled out of surface material, reinforcing methane's principal role...Surface images show small rounded pebbles in a dry riverbed. Spectra measurements are consistent with a composition of dirty water ice rather than silicate rocks, rock-like solid at Titan's temperatures.
Titan's soil appears to consist at least in part of precipitated deposits of the organic haze that shrouds the planet. This dark material settles out of the atmosphere. When washed off high elevations by methane rain, it concentrates at the bottom of the drainage channels and riverbeds contributing to the dark areas seen in DISR images.
New, stunning evidence based on finding atmospheric argon 40 indicates that Titan has experienced volcanic activity generating not lava, as on Earth, but water ice and ammonia.
Instead of liquid water, Titan has liquid methane. Instead of silicate rocks, Titan has frozen water ice. Instead of dirt, Titan has hydrocarbon particles settling out of the atmosphere, and instead of lava, Titanian volcanoes spew very cold ice." landing site
composite panorama of surface as landing- methane lake w whitecaps (cu of shore above)
Michael Hammerschlag has written articles about the Voyager missions to the Outer planets, the SETI project, and worked on the Subaru telescope on the summit of Mauna Kea, Hawaii, the biggest astronomical complex on Earth.
Titan PICS from Cassini: http://saturn.jpl.nasa.gov/news/events/titana/index.cfm
TITAN Facts: http://kvtr.elte.hu/tnp/nineplanets/titan.html
Big JPL Press Release: http://saturn.jpl.nasa.gov/news/press-kits/cassini-arrival.pdf
Huygens Instruments: http://saturn.jpl.nasa.gov/spacecraft/instruments-huygens.cfm
European Space Agency- Huygens: http://www.esa.int/SPECIALS/Cassini-Huygens/index.html
State of Space ’97: http://members.surfbest.net/mikehammer/mhmir2.htm Mir problems, Cassini launch and foretold
Mars missions failures and shuttle disaster
moon Iapetus 888 mi. diameter tar-like color is on top of ice from organic dust accumulated in orbital passage according to JPL's Johnson
River and Delta System
GASES of TITAN ATMOSPHERE
melting point (°C) -182 -183 -188 -210
boiling point (°C) -162 -89 -42 -196
Methane Ethane Propane Nitrogen
formula CH4 C2H6 C3H8 N2
To determine Kelvin temp subtract number from 273