Pluto has ‘methane dunes’

‘Nitrogen ice cannot be ruled out’

TAMPA, June 2, (AFP): Pluto is covered with surprising dunes made of methane ice, which have formed relatively recently despite the frigid dwarf planet’s very thin atmosphere, international researchers said Thursday.

Pluto’s atmosphere has a surface pressure 100,000 times lower than Earth’s, which researchers suspected might be too little to allow tiny grains of solid methane to mobilize and become airborne.

Yet mild winds blowing across Pluto’s surface at speeds of some 19-25 miles (30-40 kilometers) per hour have forged these ripples at the border of an ice plain and mountain range, said the report in the journal Science.

“The likely source of the dune grains is methane ice blown from nearby mountains,” said the Science report. “Although nitrogen ice cannot be ruled out.”

The dunes are scattered across a belt-like area some 45 miles (75 kilometers) across, and were spotted with NASA’s New Horizons spacecraft when it flew by in 2015, said the report.

“When we first saw the New Horizons images, we thought instantly that these were dunes but it was really surprising because we know there is not much of an atmosphere,” said co-author Jani Radebaugh, associate professor in the department of geological sciences at Brigham Young University.

“However despite being 30 times further away from the Sun as the Earth, it turns out Pluto still has

“Philly is committed to upholding at (the) local level the same commitment made by the US in the Paris climate agreement,” tweeted the sixth largest US city’s mayor, Jim Kenney, a Democrat.

Since then, the City of Brotherly Love has cut energy consumption in municipal buildings, started replacing street lamps with LED lights, and launched a major green energy overhaul of its celebrated museum of art.

But these actions represent just a drop in the bucket, faced with the 18 million tons of carbon spewed into the atmosphere by Philadelphia each year. Although emissions have declined, there is only so much the city can do.

Here, 85 percent of residents heat their homes with natural gas, a fossil fuel that is abundant in the rocks beneath Pennsylvania. Cars and trucks rumble through downtown — and more than half of the electricity the city gobbles up each day is produced by oil- and coal-powered power plants.

“It can’t be done by cities and states. We do need a completely clean, carbonfree grid to meet this goal,” said Christine Earth-like characteristics.”

Other cosmic bodies that are known to have dunes — besides Earth — include Mars and Venus, as well as Saturn’s moon Titan and the comet 67P/ Churyumov-Gerasimenko.

“We knew that every solar system body with an atmosphere and a solid rocky surface has dunes on it, but we didn’t know what we’d find on Pluto,” said lead author Matt Telfer, lecturer in physical geography at the University of Plymouth.

“It turns out that even though there is so little atmosphere, and the surface temperature is around -230 Celsius (-382 Fahrenheit), we still get dunes forming.”

Scientists also believe the dunes, which seem undisturbed, likely formed within the last 500,000 years, possibly much more recently.

On Earth, to form such dunes with sand requires stronger winds, said co-author Eric Parteli, lecturer in Computational Geosciences at the University of Cologne.

“The considerably lower gravity of Pluto, and the extremely low atmospheric pressure, means the winds needed to maintain sediment transport can be a hundred times lower,” he said.

On Pluto, solar radiation also causes temperature gradients in the granular ice layer, which contributes to the ability of dunes to form.

“Together, we have found that these combined processes can form dunes under normal, everyday wind conditions on Pluto,” Parteli said.

Knapp, director of the office of sustainability for the city of Philadelphia.

“We’re going to take the pieces of cleaning that grid up as much as we can, but someone still higher than us needs to set the policy that that’s what’s going to happen.”

Philadelphia is among some 2,700 cities, states and businesses that declared “We Are Still In” when it comes to the 190-plus nation Paris accord, signed in 2015.

The movement emphasizes progress, such as how carbon dioxide emissions fell in 2017 to their lowest point in 25 years, and how gigawatts of solar and wind energy have been installed as coal use declines.

In Philadelphia, a city of 1.6 million people, such gains are evident, but are also happening at a far slower pace than many would like. (AFP)

Pope to address oil majors:

The Vatican will host executives of the world’s top oil companies for a conference next week on climate change and the transition away from fossil fuels, a Vatican source said on Friday.

Three baby lions are pictured in their enclosure during their first public outing at the zoo in Frankfurt am Main, western Germany, on May 30, 2018. The lion cubs

were born on April 14, 2018 at the zoo. (AFP)