Seasons Discovered on Neptuneís Moon Triton
2010 04 08

From: Space.com


The thin atmosphere of Neptuneís moon Triton varies in thickness with the seasons and in the throes of summer, despite its relatively large distance from the sun compared to other bodies in the solar system, new observations have found.

The European Southern Observatoryís Very Large Telescope, located in Chile, made infrared observations of Triton which show that summer is in full swing in the moonís southern hemisphere, and that the warmth of the summer sun causes Tritonís thin atmosphere to thicken.

"We have found real evidence that the sun still makes its presence felt on Triton, even from so far away," said Emmanuel Lellouch of the Observatoire de Paris in France and a member of the team that made the discovery.

The telescope also discovered the presence of carbon monoxide in Tritonís atmosphere and made the first ground-based detection of methane on the Neptunian moon.


Triton, Neptuneís largest natural moon, was the last solid object visited by the Voyager 2 spacecraft on its epic 10-year tour of the outer solar system. This view of Triton was made from topographic mapping of images obtained by Voyager. Credit: NASA/JPL/Universities Space Research Association/Lunar & Planetary Institute.

Of Neptuneís 13 moons, Triton is by far the largest, and, at about 1,700 miles (2,700 km) in diameter (or three quarters of the diameter of the Earthís moon), is the seventh largest moon in the whole solar system.

Since its discovery in 1846, Triton has fascinated astronomers because of its geologic activity, the many different types of surface ices, such as frozen nitrogen as well as water and dry ice (frozen carbon dioxide), and its unique retrograde motion (which means it rotates around its planet in the opposite direction of its planetís rotation).

On Triton, where the average surface temperature is about minus 391 degrees Fahrenheit (minus 235 Celsius), it is currently summer in the southern hemisphere and winter in the northern.

As Tritonís southern hemisphere warms up, a thin layer of frozen nitrogen, methane, and carbon monoxide on Tritonís surface sublimates into gas, thickening the icy atmosphere as the season progresses during Neptuneís 165-Earth-year orbit around the sun.

A season on Triton lasts a little over 40 years, and Triton passed the southern summer solstice in 2000.

Based on the amount of gas measured, Lellouch and his colleagues estimate that Tritonís atmospheric pressure may have risen by a factor of four compared to the measurements made by Voyager 2 in 1989, when it was still spring on the giant moon. The atmospheric pressure on Triton is now between 40 and 65 microbars ó 20,000 times less than on Earth.

Carbon monoxide was known to be present as ice on the surface, but Lellouch and his team discovered that Tritonís upper surface layer is enriched with carbon monoxide ice by about a factor of ten compared to the deeper layers, and that it is this upper "film" that feeds the atmosphere.

While the majority of Tritonís atmosphere is nitrogen (much like Earthís, which is 78 percent nitrogen), the methane in the atmosphere, first detected by Voyager 2, and only now confirmed in this study from Earth, plays an important role as well.

"Climate and atmospheric models of Triton have to be revisited now, now that we have found carbon monoxide and re-measured the methane," said team member Catherine de Bergh, also of the Observatoire de Paris.

The new observations of Tritonís atmosphere are detailed in the March 15 issue of the journal Astronomy & Astrophysics.

Pluto, often considered a cousin of Triton and with similar conditions, is receiving renewed interest in the light of the carbon monoxide discovery, and astronomers are racing to find this chemical on the even more distant dwarf planet.

Article from: Space.com



Voyager 2 flyby Animation - Neptune and Triton (1989)

Video from: YouTube.com


Neptuneís moon Triton - Interesting Facts

Video from: YouTube.com



Related Articles
Real Sound of Neptune - New Voyager Recording ;)
Global Warming on Mars, Pluto, Triton and Jupiter
Does gravity change with the seasons?
Hubble shows Pluto "turning red" - Planet X?
Scientists discover Earth-like, water-rich planet: study
Earth-like planet discovered outside solar system‎
Suicidal planet seems on death spiral into star
Mars May Still Be A Living Planet, Methane In Atmosphere Reveals
NASA uses probes to hunt for ancient planet that may prove Earth moon origins
Obamaís Plan To "Geo-Engineer" The Planet Mirrors CFR Policy Documents
Odd Cloud on Neptune Seen Splitting Into Two


Latest News from our Front Page

Magaluf bar where British girl was filmed performing sex acts on 24 men is shut down after police investigation into video
2014 07 26
Is this what the youth in Britain and Europe is spending their their energy, money, efforts and innocence on? The young girl, pictured, was lured into performing multiple sex acts after organisers offered a free drink although she thought a holiday was on offer* Council officials launched an official investigation after the video went viral Playhouse bar in Magaluf and entertainment ...
Prejudice is a Form of Common Sense - Hard-Wired Into the Human Brain, Says ASU Study
2014 07 26
Contrary to what most people believe, the tendency to be prejudiced is a form of common sense, hard-wired into the human brain through evolution as an adaptive response to protect our prehistoric ancestors from danger. So suggests a new study published by Arizona State University researchers in the May issue of the "Journal of Personality and Social Psychology," which contends that, ...
The State is a Bully
2014 07 24
In the history of Western philosophy and social theory, no really silly idea has been more successful than the theory of the social contract. It is in fact not a theory of the social contract. It is a theory of the political contract. It is the idea, promoted by Thomas Hobbes, John Locke, and Jean-Jacques Rousseau, that, at some point in ...
NATO Exercise in Ukraine Coincided with MH-17 Shoot-down
2014 07 24
Rapid Trident was omitted from the flurry of coverage on the shoot-down MH-17. From the U.S. Army in Europe website: Rapid Trident supports interoperability among Ukraine, the United States, NATO and Partnership for Peace member nations. The exercise helps prepare participants to operate successfully in a joint, multinational, integrated environment with host-nation support from civil and governmental agencies. ...
Warning of íimminentí terror attack in Norway
2014 07 24
Norwegians were warned Thursday of the concrete possibility of a terror attack occurring in that country at the hands of people with connections to an extremist group in Syria. A press conference was called in Oslo, Norway on Thursday where an announcement was made of a "possible concrete threat" to national security in that country from terrorists related to an extremist ...
More News Ľ