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Fri, 18 Aug 2017
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NASA Scientist Finds a New Way to the Center of Mass of the Earth

Humans have yet to see Earth's center, as did the characters in Jules Verne's science fiction classic, "Journey to the Center of the Earth." But a new NASA study proposes a novel technique to pinpoint more precisely the location of Earth's center of mass and how it moves through space.

Knowing the location of the center of mass, determined using measurements from sites on Earth's surface, is important because it provides the reference frame through which scientists determine the relative motions of positions on Earth's surface, in its atmosphere and in space. This information is vital to the study of global sea level change, earthquakes, volcanoes and Earth's response to the retreat of ice sheets after the last ice age.

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Geologists may have found 'new' meteor crater - Montana

Two geologists from Washington traveled to north-central Montana last week after an accidental discovery of what they believe is a "new" meteorite impact crater, located just southeast of Thornhill Butte.

The Havre Daily caught up with the two St. Martin University students at Havre's Fifth Street Grind and Short Stop Thursday. The discoverers were on their way to a local laundry to dry their clothes, drenched in the previous day's rain, before heading back out in their home-built buggy, "the Mule" designed for rugged terrain.

Joe D'Alelio and Gabriel Mainwaring of Shelton, Wash. Said they had been using Google Earth to locate fossil hunting grounds when "dumb luck" led the satellite view to scan over a formation familiar, yet very exciting. "We zoomed in and saw it had the form of a meteorite impact crater," D'Alelio said.

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Physicist cracks women's random but always lucky choice of X chromosome

A University of Warwick physicist has uncovered how female cells are able to choose randomly between their two X chromosomes and why that choice is always lucky.

Human males have both a X and a Y chromosome but females have two X chromosomes. This means that in an early stage in the development of a woman's fertilised egg the cells need to silence one of those two X chromosomes. This process is crucial to survival and problems with the process are related to serious genetic diseases.

Both X chromosomes in a cell have a suicide gene called XIST which, if activated, seals the chromosome behind a barrier of RNA preventing the activation of any other gene. Researchers believe that this suicide gene can be itself blocked by a plug of proteins forming on top of its specific location on the chromosome but they had little idea as to why this should happen randomly to one X chromosome's gene and not the other.

Star

Matter Flashed at Ultra Speed: Robotic Telescope Measures Speed of Material Ejected in Cosmic Death

Using a robotic telescope at the ESO La Silla Observatory, astronomers have for the first time measured the velocity of the explosions known as gamma-ray bursts. The material is travelling at the extraordinary speed of more than 99.999% of the velocity of light, the maximum speed limit in the Universe.

"With the development of fast-slewing ground-based telescopes such as the 0.6-m REM telescope at ESO La Silla, we can now study in great detail the very first moments following these cosmic catastrophes," says Emilio Molinari, leader of the team that made the discovery.

Gamma-ray bursts (GRBs) are powerful explosions occurring in distant galaxies, that often signal the death of stars. They are so bright that, for a brief moment, they almost rival the whole Universe in luminosity. They last, however, for only a very short time, from less than a second to a few minutes. Astronomers have long known that, in order to emit such incredible power in so little time, the exploding material must be moving at a speed comparable with that of light, namely 300 000 km per second. By studying the temporal evolution of the burst luminosity, it has now been possible for the first time to precisely measure this velocity.

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The problem of space junk

When it launched its first satellite, humankind not only opened a window on the Universe, but also unveiled a sort of garbage chute, which is quickly turning near-Earth space into a gigantic waste dump filled with space and rocket debris.

At altitudes of 200 kilometers and more, we find the last stages of launch vehicles, booster sections, nose cones and decommissioned and retired satellites. Add to that the ruins of exploded spacecraft, household refuse from manned craft and orbiting stations, and such "smaller items" as bolts, washers and even tools lost by astronauts as they work outside their craft.

Near-Earth space contains about 26,000 large man-made objects and three to five times as many small elements (assembly units, jettisoned cover lids, etc.). They constantly collide with each other, and each such collision increases the number of fragments by several times.

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Mysterious signal hints at subsurface ocean on Titan

The tentative detection of low frequency radio waves on Saturn's icy moon, Titan, could signal an underground ocean of liquid water, a new study says. If so, it would be good news for the possibility of life beneath the surface of this bizarre world.

Titan's crust is thought to be made largely of water ice, kept rock hard by the prevailing surface temperature of -178° Celsius. But theoretical models of the moon's interior suggest that ammonia-rich water deep beneath the surface could stay liquid, perhaps forming a global ocean.

Telescope

NASA rover finds 'astonishing' evidence for Mars' watery past

The strongest evidence yet that ancient Mars was much wetter than it is now has been unearthed by NASA's Spirit rover.

A patch of Martian soil kicked up and analyzed by Spirit appears to be rich in silica, which suggests it would have required water to produce.

©AP photo/HO/NASA
A photo released by NASA ,shows a patch of bright-toned soil found by the Mars Rover Spirit so rich in silica that scientists propose water must have been involved in concentrating it. The silica-rich patch, informally named 'Gertrude Weise' after a player in the All-American Girls Professional Baseball League, was exposed when Spirit drove over it during the 1,150th Martian day, or sol, of Spirit's Mars surface mission (March 29, 2007). One of Spirit's six wheels no longer rotates, so it leaves a deep track as it drags through soil. Most patches of disturbed, bright soil that Spirit had investigated previously are rich in sulfur, but this one has very little sulfur and is about 90 percent silica.

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Mars rover finds "puddles" on the planet's surface

A new analysis of pictures taken by the exploration rover Opportunity reveals what appear to be small ponds of liquid water on the surface of Mars.

The report identifies specific spots that appear to have contained liquid water two years ago, when Opportunity was exploring a crater called Endurance. It is a highly controversial claim, as many scientists believe that liquid water cannot exist on the surface of Mars today because of the planet's thin atmosphere.

©Ron Levin
Smooth bluish areas on a Martian crater floor could be ponds, according to two scientists. The area is approximately 1 square metre.

Satellite

Israel's Space Agency: We'll launch more satellites by 2010

Following launching of Ofek-7 into space, officials say more advanced satellites will be launched in coming years

©Defense Ministry
Ofek-7 being launched

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Ice ages dried up African monsoons

When ice ages held Europe in their grip, Africa also felt the pinch - though in a different way.

It has long been suspected that there is a connection between the west African monsoon and climate at higher latitudes - especially over geological timescales, says David Lea at the University of California, Santa Barbara. "But until now, there hasn't been enough supporting evidence." Now Lea, with team leader Syee Weldeab and colleagues, has reconstructed the most detailed history of the monsoon yet, spanning 155,000 years and two ice ages.