Seasons Discovered on Neptune’s Moon Triton
2010 04 08

From: Space.com


The thin atmosphere of Neptune’s 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 Observatory’s Very Large Telescope, located in Chile, made infrared observations of Triton which show that summer is in full swing in the moon’s southern hemisphere, and that the warmth of the summer sun causes Triton’s 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 Triton’s atmosphere and made the first ground-based detection of methane on the Neptunian moon.


Triton, Neptune’s 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 Neptune’s 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 Earth’s 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 planet’s 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 Triton’s southern hemisphere warms up, a thin layer of frozen nitrogen, methane, and carbon monoxide on Triton’s surface sublimates into gas, thickening the icy atmosphere as the season progresses during Neptune’s 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 Triton’s 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 — 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 Triton’s 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 Triton’s atmosphere is nitrogen (much like Earth’s, 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 Triton’s 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


Neptune’s 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
Obama’s Plan To "Geo-Engineer" The Planet Mirrors CFR Policy Documents
Odd Cloud on Neptune Seen Splitting Into Two


Latest News from our Front Page

Extremists to have Facebook and Twitter vetted by anti-terror police
2014 09 30
Theresa May to announce new Extremist Disruption Orders to strengthen counter-terrorism if the Tories win the next general election Extremists will have to get posts on Facebook and Twitter approved in advance by the police under sweeping rules planned by the Conservatives. They will also be barred from speaking at public events if they represent a threat to “the functioning of democracy”, ...
Scottish Independence: Protesters demand revote
2014 09 30
Pro-independence campaigners gathered outside the Scottish Parliament for the second day in a row, this time to demand a revote of the September 18 referendum. While yesterday’s “Rally For A Revote” saw the return of Saltires and Yes banners to Holyrood, it did not match the turnout for the “Voice Of The People” rally held on Saturday, when up 3000 people ...
Water rationing hits California: limit of 50 gallons per person per day or face fines of $500
2014 09 29
Millions of Californians are about to be hit with strict water rationing -- daily "allocation" numbers that represent the maximum amount of water you’re allowed to use for any purpose. Households that exceed the allocation limit will face stiff fines of hundreds of dollars per violation. "In July, the State Water Resources Control Board passed stage one emergency regulations, giving powers ...
Much of Earth’s Water is Older than the Sun
2014 09 29
Much of the water on Earth and elsewhere in the solar system likely predates the birth of the sun, a new study reports. The finding suggests that water is commonly incorporated into newly forming planets throughout the Milky Way galaxy and beyond, researchers said — good news for anyone hoping that Earth isn’t the only world to host life. “The implications of ...
Did the Vikings Get a Bum Rap?
2014 09 29
A Yale historian wants us to rethink the terrible tales about the Norse. This illustration shows the stereotype of Viking marauders wreaking mayhem, even on clergy. The scene depicts the monastery at Clonmacnoise, Ireland. The Vikings gave no quarter when they stormed the city of Nantes, in what is now western France, in June 843—not even to the monks barricaded in the ...
More News »