Neptunes south pole is warmer by 10 degrees, reveals study

An international team of astronomers have using the European Southern Observatorys (ESOs) Very Large Telescope (VLT), discovered that Neptunes south pole is much hotter than the rest of the planet.

Washington, Sept 19 : An international team of astronomers have using the European Southern Observatory's (ESO's) Very Large Telescope (VLT), discovered that Neptune's south pole is much hotter than the rest of the planet.

The team found that the warm south pole is providing an avenue for methane to escape out of the planet's deep atmosphere.

"The temperatures are so high that methane gas, which should be frozen out in the upper part of Neptune's atmosphere, the stratosphere, can leak out through this region," said Glenn Orton of NASA's Jet Propulsion Laboratory, Pasadena, California.

In their study in the September 18 issue of the journal of Astronomy and Astrophysics, Orton and his team report that the temperature at Neptune's south pole is hotter than anywhere else on the planet by about 10 degrees Celsius (18 degrees Fahrenheit).

The average temperature on Neptune is about minus 200 degrees Celsius (minus 392 degrees Fahrenheit).

Neptune, the farthest known planet of our solar system, is located about 30 times farther away from the Sun than the Earth is. Only about one thousandth of the sunlight received by our planet reaches Neptune. Yet, the small amount of Sunlight Neptune does receive significantly affects the planet's atmosphere.

During their study, the researchers found that these temperature variations were consistent with seasonal changes.

A Neptunian year lasts about 165 Earth years. It has been summer in the south pole of Neptune for about 40 years now, and scientists predict that as winter turns to summer at the north pole, an abundance of methane would leak out of a warm north pole in about 80 years.

"Neptune's south pole is currently tilted toward the Sun, just as the Earth's south pole is tilted toward Sun during summer in the southern hemisphere," said Orton.

"But on Neptune, the antarctic summer lasts 40 years instead of a few months, and a lot of solar energy input during that time can make big temperature differences between the regions in continual sunlight and those with day-night variations.

"This is a likely factor in Neptune having the strongest winds of any planet in the solar system; sometimes, the wind blows there at more than 2,000 kilometres per hour," said Orton.

Orton said, the new observations have also revealed mysterious high-latitude "hot spots" in the stratosphere that have no immediate analogue in other planetary atmospheres.

The scientists believe this feature was generated by upwelling gas from much deeper in the atmosphere.

Methane is not the primary constituent of Neptune's atmosphere, which, as a giant planet, is mostly composed of the light gases, hydrogen and helium.

Yet, it is the methane in Neptune's upper atmosphere that absorbs the red light from the Sun and reflects the blue light from the Sun back into space, making the planet appear blue.

ANI