Icy basin in Pluto may be a natural sinkhole

‘Big heart’ caused depression

CAPE CANAVERAL, Florida, Dec 1, (Agencies): The deep icy basin in Pluto’s heart-shaped region may be a natural sinkhole.

In a study published Wednesday, a team led by University of Maryland astronomer Douglas Hamilton suggests the basin may have resulted from the weight of surface ice.

Computer modeling by the researchers indicates an ice cap formed at that location early in Pluto’s history. All that ice may have caused the underlying crust to slump, creating the 600-mile-wide basin in the left lobe of the heart, now called Sputnik Planitia. Other models point to a crater caused by an impact.

“Pluto’s big heart weighs heavily on the small planet, leading inevitably to depression,” Hamilton said in a statement. He noted that the Greenland Ice Sheet on Earth created a basin in similar manner.

NASA’s New Horizons spacecraft unveiled Pluto during last year’s historic flyby.

Two weeks ago, another study in the same journal, Nature, suggested an ocean beneath Sputnik Planitia, named after Earth’s first man-made satellite. Hamilton said that still could be the case.

“While we cannot conclude definitively that there is an ocean under Pluto’s icy shell, we also cannot state that there is not one,” Hamilton said.

Launched in 2006, New Horizons is now more than 374 million miles from Pluto and enroute to another much smaller object in the so-called Kuiper Belt on the frozen fringes of the solar system; that close encounter is set for 2019. Mission Control is located at Johns Hopkins University.

Hamilton

Cassini embarks on Saturn mission:

Consider it a cosmic carousel with countless rings up for grabs.

NASA’s Saturn-orbiting spacecraft, Cassini, has begun an unprecedented mission to skim the planet’s rings. On Tuesday, Cassini got a gravitational assist from Saturn’s big moon Titan. That put the spacecraft on course to graze Saturn’s main outer rings over the next five months.

The first orbit of this new venture begins Wednesday night. Then on Sunday, an engine firing by Cassini should seal the deal, with the spacecraft making its first ring crossing.

Launched nearly 20 years ago, Cassini will swoop down through the outer edge of rings every seven days. The spacecraft should make 20 dives through April, observing some of Saturn’s many mini moons and even sampling ring particles and gases.

This will be Cassini’s last hurrah before a suicide plunge into Saturn next September.

New algorithm boosts crowd-mapping:

Humanitarian workers delivering aid to regions hit by natural disasters might find it a little easier to reach people most in need of help following new advances in crowd-sourced mapping technology, researchers said on Wednesday.

Traditional maps often do not give rescue workers the information they need when disasters strike, such as which buildings and bridges have been destroyed.

Crowd-mapping, where volunteers on the ground send real-time information about which roads are open and where people could be trapped following earthquakes or hurricanes, has become increasingly popular with aid groups, US researchers said.