'Supermoon': Biggest Full Moon of 2014

An astrophotographer captured this photo of the supermoon rising behind a lighthouse and some observers on Aug. 10, 2014.

Credit: Mark Gee

Photographers around the world ventured outside Sunday (Aug. 10) to snap photos of the bright, full "supermoon" rising in the night sky.

August's full moon, called a supermoon because it is occurred when the moon was closest to Earth in its orbit, wowed skywatchers, inspiring some of them to turn their cameras skyward to catch breathtaking views of the biggest full moon of 2014.

Some photographers had to wait for a break in the clouds to capture their images, while others chased the moon to different observing sites.

NASA Cassini prepares for its biggest remaining burn

This is an artists concept of Cassini during the Saturn Orbit Insertion (SOI) maneuver, just after the main engine has begun firing. 

Credit: NASA/JPL

NASA's Cassini spacecraft will execute the largest planned maneuver of the spacecraft's remaining mission on Saturday, Aug. 9.

The maneuver will target Cassini toward an Aug. 21 encounter with Saturn's largest moon, Titan.

The main engine firing will last about a minute and will provide a change in velocity of 41 feet per second (12.5 meters per second).

This is the largest maneuver by Cassini in five years. No other remaining maneuver comes close, in the amount of propellant it will consume and the amount by which it will change the spacecraft's velocity.

By contrast, the smallest maneuvers Cassini routinely executes are about 0.4 inches (10 millimeters) per second.

The large size of the Aug. 9 burn is needed to begin the process of "cranking down" Cassini's orbit, so that the spacecraft circles Saturn nearer to the plane of the rings and moons.

Previously, with each Titan flyby, mission controllers adjusted the spacecraft's orbit to be increasingly inclined, carrying Cassini high above Saturn's polar regions.

The upcoming maneuver starts reversing that trend, making the orbit increasingly close to the equator.

Although Cassini has occasionally performed similar large propulsive maneuvers during its decade in the Saturn system, Titan itself has proven to be the workhorse for steering Cassini around Saturn.

It is not uncommon for the spacecraft to receive a gravitational assist, or boost, from Titan that rivals or exceeds the 96-minute engine burn Cassini performed in 2004 to insert itself into Saturn orbit.

The Cassini mission recently celebrated a decade studying Saturn, its rings, moons and magnetosphere.

Tamu Massif: Monster volcano is one of the biggest in Solar System

MCS reflection Line A–B, across the axis of Tamu Massif. 

Credit: Nature

Geologists on Thursday announced they had uncovered a stupendous volcano that is the biggest in the world and rivals the greatest in the Solar System.

Dubbed Tamu Massif, the volcano is part of the Shatsky Rise, a deep plateau on the floor of the Pacific located around 1,600 kilometres (1,000 miles) east of Japan, they said.

It comprises a single, immense, rounded dome in the shape of a shield, formed of hardened lava from an eruption around 144 million years ago.

It covers around 310,000 square kilometres (119,000 square miles)—the equivalent area of Britain and Ireland combined—and slopes upwards to a height of around 3.5 kms (2.2 miles) above the sea floor.

"Tamu Massif is the largest known single, central volcano in the world," the team reported in the journal Nature Geoscience.

The slope of lava layers within Tamu Massif indicate that it formed from a central volcanic vent.

William Sager, University of Houston

In area, "it is... approximately the same as the British Isles or Olympus Mons on Mars, which is considered the largest volcano in the Solar System."

It adds: "Although Olympus Mons seems to be a giant because it is more than 20 kms (12 miles) in height, its volume is only around 25 percent larger."

Olympus Mons, in addition, has relatively shallow roots, whereas Tamu Massif delves some 30 kilometres (18 miles) into Earth's crust.

Ocean surveyors had until now surmised Tamu Massif to be a vast system of multiple volcanoes, a kind that exists in about a dozen locations around the planet.

The realisation that it was a single volcano of truly massive size only came to light when the team, led by William Sager at Texas A&M University, sought an overview.

They assembled data from rock samples, taken from an ocean-floor drilling project, and a chart of the seabed, provided by deep-penetration seismic scanners aboard a survey ship.

Put together, the findings suggest mega-volcanoes found in other parts of the Solar System have cousins on Earth, says the paper.

"The Earth variety is poorly understood because these monsters found a better place to hide—beneath the sea," it argues.

In an email exchange with AFP, Sager said it seemed unlikely that Tamu Massif was still active.

"The bottom line is that we think that Tamu Massif was built in a short (geologically speaking) time of one to several million years and it has been extinct since," he said.

"One interesting angle is that there were lots of oceanic plateaus (that) erupted during the Cretaceous Period (145-65 million years ago) but we don't see them since. Scientists would like to know why."

Other volcanic leviathans could be lurking among the dozen or so large oceanic plateaux around the world, he thought.

More information: dx.doi.org/10.1038/ngeo1934