Earth's Center Is 1,000 Degrees Hotter Than Previously Thought, Synchrotron X-Ray Experiment Shows
Scientists have determined the temperature near the Earth’s center to be 6000 degrees Celsius, 1000 degrees hotter than in a previous experiment run 20 years ago. These measurements confirm geophysical models that the temperature difference between the solid core and the mantle above, must be at least 1500 degrees to explain why the Earth has a magnetic field.
For more information about this study, see the press release from the European Synchrotron Radiation Facility.
Ocean Volcanic Rocks Contain Samples of Recycled Crust
Scientists have long believed that lava erupted from certain oceanic volcanoes contains materials from the early Earth’s crust. But decisive evidence for this phenomenon has proven elusive. New research from a team including Carnegie’s Erik Hauri demonstrates that oceanic volcanic rocks contain samples of recycled crust dating back to the Archean era 2.5 billion years ago. Their work is published in Nature.
Oceanic crust sinks into the Earth’s mantle at so-called subduction zones, where two plates come together. Much of what happens to the crust during this journey is unknown. Model-dependent studies for how long subducted material can exist in the mantle are uncertain and evidence of very old crust returning to Earth’s surface via upwellings of magma has not been found until now.
For more information about these results, see the press release from the Carnegie Institution.
All through the galaxy, we find stars that pulsate. Gravity makes stars
spherically symmetric. Because of this symmetry, we can describe the
pulsations with mathematical functions called spherical harmonics. The
patterns of these functions depend on two numbers, usually called the
spherical degree ("l") and the azimuthal order ("m").
The spherical degree changes the total number of hot and cool zones on the
surface. The azimuthal order can only be between "-l" and "+l", and
changes how the hot and cool zones are distributed on the surface of the
From a distance, we can only see the brightness of a star change when the
spherical degree is small. Play with the values of "l" and "m" to see some
of the different ways stars can pulsate.
I am Katrien, a Belgian astronomer. I have been working in several European countries and I am currently based in Paris, France. My research is very exciting as I study stars that pulsate! This means...more
Hi to all from the IAC80 telescope on the island of Tenerife, hidden away on the Canary Islands. Last month, one of my friends, Katrien, was here and she told you a little about observing stars that pulsate....more
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The introduction of telescopes to the study of astronomy opened up the universe, but it took some time for astronomers to realize how vast the universe could be. Telescopes revealed that our night sky...more