Inter-stellxr-blog - Lost Among The Stars

Magnetic mystery of Earth's early core explained

Competing ideas suggest how sloshing motions could maintain a primordial magnetic field.

Geophysicists call it the new core paradox: They can’t quite explain how the ancient Earth could have sustained a magnetic field billions of years ago, as it was cooling from its fiery birth.

Now, two scientists have proposed two different ways to solve the paradox. Each relies on minerals crystallizing out of the molten Earth, a process that would have generated a magnetic field by churning the young planet’s core. The difference between the two explanations comes in which particular mineral does the crystallizing.

Silicon dioxide is the choice of Kei Hirose, a geophysicist at the Tokyo Institute of Technology who runs high-pressure experiments to simulate conditions deep within the Earth. “I’m very confident in this,” he reported on 17 December at a meeting of the American Geophysical Union in San Francisco, California.

But David Stevenson, a geophysicist at the California Institute of Technology in Pasadena, says that magnesium oxide — not silicon dioxide — is the key to solving the problem. In unpublished work, Stevenson proposes that magnesium oxide, settling out of the molten early Earth, could have set up the buoyancy differences that would drive an ancient geodynamo.

The core paradox arose in 2012, when several research teams reported that Earth’s core loses heat at a faster rate than once thought1, 2. More heat conducting away from the core means less heat available to churn the core’s liquid. That’s important because some studies suggest Earth could have had a magnetic field more than 4 billion years ago —  just half a billion years after it coalesced from fiery debris swirling around the newborn Sun. “We need a dynamo more or less continuously,” Peter Driscoll, a geophysicist at the Carnegie Institution for Science in Washington DC, said at the meeting.

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clouds on mars, photographed by mars express, 16th january 2014.

around 43°s 258°e, one the eastern icaria planum. details from a sequence of 5 monochrome images, colourized with a bit of art and a bit of science.

image credit: esa. animation & colourization: ageofdestruction.

ISS Symphony

What is this? http://space-pics.tumblr.com/ source:http://imgur.com/r/Astronomy/WhU2y3g

Hiro:... Hey tadashi.

Tadashi: yeah?

Hiro: is that a mirror in your pants?

Tadashi: what?

Hiro: cause i can see me in 'em.

Tadashi:...

Tadashi:...

Hiro: well?

Tadashi:... Get out.

The rings of Saturn as seen from the Cassini space probe. (via)

The forward bulkhead and tunnel for Exploration Mission 1 undergoing paint priming, October 9, 2015. The EM-1 Orion capsule is being fabricated at the Michoud Assembly Facility in New Orleans, Louisiana. Seven major components are welded together to create the capsule’s pressure vessel. It then gets shipped to Kennedy Space Center in Florida where it undergoes final assembly and outfitting of key systems.

Boeing 747 carrying space shuttle Endeavor

Scientists spot the closest Earth-sized exoplanet yet

Scientists have discovered a new exoplanet that, in the language of “Star Wars,” would be the polar opposite of frigid Hoth, and even more inhospitable than the deserts of Tatooine. But instead of residing in a galaxy far, far away, this new world is, galactically speaking, practically next door. The new planet, named GJ 1132b, is Earth-sized and rocky, orbiting a small star located a mere 39 light-years from Earth, making it the closest Earth-sized exoplanet yet discovered. Based on their measurements, the scientists have determined that the planet is a roasting 500° F (260° C), and it is likely tidally locked, meaning that it has a permanent day and night side — presenting the same face to its star, much like our Moon is locked to Earth.

Read more ~ Astronomy Magazine

Image: In this artist’s rendering of GJ 1132b, a rocky exoplanet similar to Earth in size and mass, circles a red dwarf star. GJ 1132b is relatively cool at about 450° F (230° C) and could potentially host an atmosphere. At a distance of only 39 light-years, it will be a prime target for additional study with Hubble and future observatories like the Giant Magellan Telescope.    Credit: Dana Berry