Rocky planets such as Earth and Mars are born when small particles smash together to form larger, planet-sized clusters in a planet-forming disk, but researchers are less sure about how gas-giant planets such as Jupiter and Saturn form. Is core accretion--the process that creates their smaller, terrestrial cousins--responsible? Or could an alternate model known as disk instability--in which the planet-forming disk itself actually fragments into a number of planet-sized clumps--be at work? Could both be possible under different circumstances?
Recent work from the Carnegie Institutions Department of Terrestrial Magnetism explores both possibilities. This and other relevant work regarding planet formation is presented at the NASA Astrobiology Science Conference (AbSciCon) 2006 at the Ronald Reagan Building in Washington, D.C. March 26-30. See http://abscicon2006.arc.nasa.gov/ for details.
Carnegie Fellow Hannah Jang-Condell1 has devised a method to catch the early stages of gas-giant core accretion in the act. If actively accreting cores exist, they should leave a gravitational "dimple" in the planet-forming disk--even if the cores are only a fraction the size of Jupiter. Since disk instability would result in planet-sized fragments straight away, the existence of these young, intermediate-sized cores would be a clear indicator of core accretion.
Alan Boss | EurekAlert!
Astronomers find unexpected, dust-obscured star formation in distant galaxy
24.03.2017 | University of Massachusetts at Amherst
Gravitational wave kicks monster black hole out of galactic core
24.03.2017 | NASA/Goddard Space Flight Center
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
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