Huygens
- För andra betydelser, se Huygens (olika betydelser).
 Huygens, innan den skickades ut i rymden | |
| Status | Uppdrag slutfört |
|---|---|
| Typ | Landare |
| Organisation | ESA/NASA |
| Moderfarkost | Cassini |
| NSSDC-ID | 1997-061C[1] |
| Uppdragets varaktighet | ~20 dagar |
| Webbplats | Huygens hem |
| Landning | |
| Landning | Titan |
| Tidpunkt för landning | 14 januari, 2005 |
| Egenskaper | |
| Massa | 319 kg |
Huygens (efter Christiaan Huygens) är en rymdsond utsänd av ESA den 15 oktober, 1997 som den 14 januari, 2005 landade på en av Saturnus månar, Titan, efter att ha separerats från moderfarkosten Cassini den 25 december, 2004. Sonden kom in i atmosfären 11:13 och landade 13:45. Titan anses vara av extra vetenskapligt intresse eftersom dess atmosfär har stora likheter med Jordens innan livets uppkomst.
På farkosten fanns tolv vetenskapliga experiment. De mätte atmosfärens innehåll (på ett flertal olika sätt, både med avseende på olika gaskoncentrationer och aerosoler), vindhastigheter, planetytans egenskaper med mera.
De flesta mätningarna utfördes som planerat under den cirka 2 timmar långa nedstigningen. Om sonden skulle överleva själva landningen var ända sedan projektets planering en öppen fråga och det ansågs mest som en lyckosam bonus ifall man skulle få någon data från månens yta. Landningen gick dock bra och Huygens sände data och bilder via Cassini tillbaka till jorden under några timmar.
De signaler som sändes togs emot av Nasas Deep Space Network och vidarebefordrades till Esas kontrollstation i Darmstadt, Tyskland. De första signalerna togs emot klockan 17:19.
Vetenskapliga resultat
Mätningar från atmosfären visar att månens stratosfär består av en likformig blandning av metan och kvävgas. I troposfären ökar metanhalten med minskad höjd. Moln av metan finns på 20 kilometers höjd.
Nedfarten genom atmosfären gick ryckigare än förväntat på grund av en oväntad vindprofil på 25 kilometers höjd.
Galleri
Den här filmen är skapad med data som samlats in under Huygenssondens nerstigning och landning 14 januari 2005, kameran finansierades av NASA.
Rymdsonden Cassini med sina olika komponenter och Huygens
Bild från Titan tagen av Huygens.
Källor
Wikimedia Commons har media som rör Huygens.- ESA: Cassini-Huygens
Wikimedia Commons har media som rör Fotnoter
- ^ ”NASA Space Science Data Coordinated Archive” (på engelska). NASA. https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1997-061C. Läst 1 april 2020.
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Media som används på denna webbplats
Författare/Upphovsman: David Monniaux, Licens: CC BY-SA 3.0
The Huygens probe; scale 1 facsimile
This movie, built with data collected during the European Space Agency's Huygens probe on Jan. 14, 2005, shows the operation of the Descent Imager/Spectral Radiometer camera during its descent and after touchdown. The camera was funded by NASA.
The almost four-hour-long operation of the camera is shown in less than five minutes. That's 40 times the actual speed up to landing and 100 times the actual speed thereafter.
The first part of the movie shows how Titan looked to the camera as it acquired more and more images during the probe's descent. Each image has a small field of view, and dozens of images were made into mosaics of the whole scene.
The scientists analyzed Huygens' speed, direction of motion, rotation and swinging during the descent. The movie includes sidebar graphics that show:
- (Lower left corner) Huygens' trajectory views from the south, a scale bar for comparison to the height of Mount Everest, colored arrows that point to the sun and to the Cassini orbiter.
- (Top left corner) A close-up view of the Huygens probe highlighting large and unexpected parachute movements, a scale bar for comparison to human height.
- (Lower right corner) A compass that shows the changing direction of view as Huygens rotates, along with the relative positions of the sun and Cassini.
- (Upper right corner) A clock that shows Universal Time for Jan. 14, 2005 (Universal Time is 7 hours ahead of Pacific Daylight Time). Above the clock, events are listed in mission time, which starts with the deployment of the first of the three parachutes.
Sounds from a left speaker trace Huygens' motion, with tones changing with rotational speed and the tilt of the parachute. There also are clicks that clock the rotational counter, as well as sounds for the probe's heat shield hitting Titan's atmosphere, parachute deployments, heat shield release, jettison of the camera cover and touchdown.
Sounds from a right speaker go with the Descent Imager/Spectral Radiometer activity. There's a continuous tone that represents the strength of Huygens' signal to Cassini. Then there are 13 different chimes - one for each of instrument's 13 different science parts - that keep time with flashing-white-dot exposure counters. During its descent, the Descent Imager/Spectral Radiometer took 3,500 exposures.
The Huygens probe was delivered to Saturn's moon Titan by the Cassini spacecraft, which is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif. NASA supplied two instruments on the probe, the descent imager/spectral radiometer and the gas chromatograph mass spectrometer.
NASA's Voyager 1 took this photograph of Saturn on Oct. 18, 1980,34 million kilometers (21.1 million miles) from the planet. The photograph was taken on the last day that Saturn and its rings could be captured within a single narrow-angle camera frame as the spacecraft closed in on the planet for its nearest approach on Nov. 12. Dione, one of Saturn's inner satellites, appears as three color spots just below the planet's south pole. An abundance of previously unseen detail is apparent in the rings. For example, a gap in the dark, innermost ring, called the C-ring or crepe ring, is clearly shown. Material is seen within the relatively wide Cassini Division, separating the middle, B-ring from the outermost ring, the A-ring. The Encke Division is shown near the outer edge of the A-ring. The detail in the rings' shadows cast on the planet is of particular interest: the broad, dark band near the equator is the shadow of the B-ring; the thinner, brighter line is just to the south of the shadow of the less dense A-ring.
