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Primeur weekly 2018-08-13

Focus

DEEP-EST project is exploring the nuts and bolts of mildly disruptive modular supercomputing architecture ...

Gidel's FPGAs only use 1% of their capacity for lossless compression and encryption ...

German HPC and EuroHPC, a question of competitive collaboration benefiting science ...

Quantum computing

NSF launches effort to create practical quantum computer ...

The Rigetti 128-qubit chip and what it means for quantum ...

Quantum chains in graphene nanoribbons ...

Tying electrons down with nanoribbons ...

Focus on Europe

Falling moons: When proto-Earth met its makers - German and Israeli supercomputers spend 100 weeks crunching astronomical numbers ...

PRACE SHAPE Programme supports three further SMEs ...

High Performance Computing for a better agriculture ...

ExCAPE: developing new medicines with high performance computing ...

RDA Grants for Early Careers and Experts - Join the 12th RDA Plenary, 5-8 November 2018, Botswana as part of the International Data Week 2018 ...

Middleware

NetApp and NVIDIA supercharge deep learning with new AI architecture ...

Ohio Supercomputer Center hosting sixth meeting of the MVAPICH Users Group ...

Julia 1.0 has now been released ...

Hardware

Supermicro opens new era of petascale computing with a family of all-flash NVMe 1U systems scalable up to a petabyte of high performance storage ...

DDN building new flash enterprise virtualisation and analytics division with 100 new hires planned through September ...

Co-construction of the future university: Sugon signs with XJTLU ...

Intel launches world's densest, totally silent solid state drive ...

Intel's vision for the future of memory and storage with Optane + QLC ...

University of Texas at Arlington researcher working to use computer cache to speed up memory access ...

Applications

Blue Waters professor Kaiyu Guan receives AGU Early Career Award ...

NCSA Brown Dog project wins Best Technical Paper at PEARC18 ...

2018 NCSA Blue Waters Symposium presentations now available ...

Supercomputer simulations show new target in HIV-1 replication ...

Falling moons: When proto-Earth met its makers - German and Israeli supercomputers spend 100 weeks crunching astronomical numbers

6 Aug 2018 Tübingen - The Moon is Earth's only natural satellite. Its creation still raises many questions for astrophysical research - indeed, the Moon may not have been alone in the skies of primeval Earth. Recent studies have shown that there was once a number of smaller moons - known as moonlets - yet we do not know what became of them.

Working with Dr. Uri Malamud and Professor Hagai Perets of the Israeli Institute of Technology in Haifa and Christoph Burger of the University of Vienna, University of Tübingen's Christoph Schäfer has been investigating to find out what happened to Earth's moonlets. The researchers' complex simulations show that they could have fallen to Earth in collisions which changed the composition of Earth's mantle. Their study has been published in the latest edition ofMonthly Notices of the Royal Astronomical Society.

According to the currently-accepted theory, the Moon was created some 4.5 billion years ago in a collision between the proto-Earth and another proto-planet the size of Mars. Astrophysicists call this proto-planet Theia. That led to the formation of a disc around the Earth, composed of material thrown out of both bodies by the collision. The material in the disc eventually conglomerated into the Moon we know today.

But the latest research shows that the Earth was subject to not one, but several such major collisions; and that smaller bodies hit the proto-Earth even more frequently. These processes led to the formation of several moonlets, which the researchers have assumed to have each been between one-sixth and half of the Moon's mass.

The astrophysicists have been investigating their fate. "There are two possibilities: The moonlets may have joined up under the force of gravity to form larger objects, or - the other possibility - they may have been pulled down to the Earth", Christoph Schäfer explained. "Those are the two options we are looking at first and foremost."

To simulate the collisions of the moonlets with the Earth, the researchers used a computer programme developed under Christoph Schäfer's direction at the Tübingen Institute of Astronomy and Astrophysics by Professor Wilhelm Kley's working group. The calculations themselves were conducted in the Tübingen BinAC computer cluster and the TAMNUN cluster in Israel. The Tübingen physicists' programme used smooth particle hydrodynamics to model the processes, and graphics processing units to accelerate the highly complex computations. Christoph Burger of the Vienna University Institute for Astronomy and Astrophysics wrote the code for the complicated initial conditions for the simulations.

The astrophysicists assumed a simplified model of the proto-Earth and a falling moonlet - in which both had an iron core and a silicate mantle. The core was set at one-third of the mass of each body. The group carried out more than 70 simulations of a moonlet colliding with the Earth, varying parameters such as the angle of impact, the size of the moonlet, and the rotational velocity of the Earth. "In total, the calculations took more than 100 weeks of computing time", stated Uri Malamud.

In Haifa, Uri Malamud analyzed the results of the simulations. He determined which fragments of the bodies would have been able to escape from the system, which would have entered a captured orbit around the Earth, and which would remain after hitting the Earth. He also calculated the change in the Earth's rotation period caused by the collision. "Our results show that when a moonlet strikes the Earth, the incoming material is not homogeneously distributed. This kind of collision can therefore lead to asymmetries and inhomogenities in the composition of the Earth's mantle", stated Uri Malamud. This collaborative research gives us a more complete picture of how the Moon was created and places it into the broader context of planetary formation in the solar system.

Uri Malamud, Hagai B Perets, Christoph Schäfer, and Christoph Burger are the authors of the paper titled " Moonfalls: collisions between the Earth and its past moons ". The paper has been published inMonthly Notices of the Royal Astronomical Society.
Source: University of Tübingen

Back to Table of contents

Primeur weekly 2018-08-13

Focus

DEEP-EST project is exploring the nuts and bolts of mildly disruptive modular supercomputing architecture ...

Gidel's FPGAs only use 1% of their capacity for lossless compression and encryption ...

German HPC and EuroHPC, a question of competitive collaboration benefiting science ...

Quantum computing

NSF launches effort to create practical quantum computer ...

The Rigetti 128-qubit chip and what it means for quantum ...

Quantum chains in graphene nanoribbons ...

Tying electrons down with nanoribbons ...

Focus on Europe

Falling moons: When proto-Earth met its makers - German and Israeli supercomputers spend 100 weeks crunching astronomical numbers ...

PRACE SHAPE Programme supports three further SMEs ...

High Performance Computing for a better agriculture ...

ExCAPE: developing new medicines with high performance computing ...

RDA Grants for Early Careers and Experts - Join the 12th RDA Plenary, 5-8 November 2018, Botswana as part of the International Data Week 2018 ...

Middleware

NetApp and NVIDIA supercharge deep learning with new AI architecture ...

Ohio Supercomputer Center hosting sixth meeting of the MVAPICH Users Group ...

Julia 1.0 has now been released ...

Hardware

Supermicro opens new era of petascale computing with a family of all-flash NVMe 1U systems scalable up to a petabyte of high performance storage ...

DDN building new flash enterprise virtualisation and analytics division with 100 new hires planned through September ...

Co-construction of the future university: Sugon signs with XJTLU ...

Intel launches world's densest, totally silent solid state drive ...

Intel's vision for the future of memory and storage with Optane + QLC ...

University of Texas at Arlington researcher working to use computer cache to speed up memory access ...

Applications

Blue Waters professor Kaiyu Guan receives AGU Early Career Award ...

NCSA Brown Dog project wins Best Technical Paper at PEARC18 ...

2018 NCSA Blue Waters Symposium presentations now available ...

Supercomputer simulations show new target in HIV-1 replication ...