2020
October
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Astronomers are searching for the super planet

Again and again, astronomers proudly present exoplanets that would be suitable for life as we know it – i.e. made of solid rock and illuminated by their stars in such a way that water exists on their surface in a liquid state. But is our home planet really ideal for the development of life? After all, when the sun was still young and shone with a third less power, it was still quite cold here until CO2 finally created a greenhouse effect.

A study under the direction of the scientist Dirk Schulze Makuch of the Washington State University and the Technical University of Berlin, which was published recently in the magazine Astrobiology, therefore now describes characteristics of potential “overhabitable” planets, to which also those belong, that are older, somewhat larger, somewhat warmer and possibly more humid than Earth. Life could also more easily flourish on planets orbiting slower changing stars with longer lifetimes than our Sun.

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Why Jupiter’s storms behave so strangely

At the south pole of Jupiter there is an impressive sight – even for a gas giant covered with colored bands, which carries a red spot larger than the earth. Near its south pole, a cluster of swirling storms has formed, arranged in a geometric pattern. Since they were first sighted by the NASA space probe Juno in 2019, the storms have puzzled scientists. Basically, they resemble hurricanes on Earth. However, storms on our planet do not gather at the poles and swirl around each other as a pentagon or hexagon.

Now a research team in the laboratory of Andy Ingersoll, Caltech Professor of Planetary Research, has discovered why Jupiter’s storms behave so strangely. They used formulas derived from a proof written almost 150 years ago by Lord Kelvin, a British mathematical physicist and engineer. Ingersoll, who was a member of the Juno team, says that Jupiter’s storms are remarkably similar to those that strike the east coast of the United States every summer and fall, only they are much larger.

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Black holes reveal themselves in the X-ray spectrum

Black holes are the remnant of stars with more than eight solar masses. Everything we know points to their existence – the theory of relativity, cosmology, etc. And yet, only one supermassive black hole – with a mass of more than 6 billion solar masses – has been “photographed” to date with the help of surrounding radiation in the radio wavelength range. But stellar-mass black holes have not yet been seen.

That’s why scientists are pleased that an international team of astrophysicists has now found distinct signatures of the event horizon of black holes that clearly distinguish them from neutron stars – objects comparable in mass and size with black holes, but that do not have an event horizon. This is by far the strongest evidence to date of the existence of stellar-mass black holes.

The team, made up of Mr. Srimanta Banerjee and Professor Sudip Bhattacharyya of the Tata Institute for Fundamental Research, India, and Professor Marat Gilfanov and Professor Rashid Sunyaev of the Max Planck Institute for Astrophysics, Germany, and the Space Research Institute of the Russian Academy of Science, Russia, published this research in a paper in the Monthly Notices of the Royal Astronomical Society.

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Fresh frozen items delivered to Enceladus’s north pole too

No, unfortunately nobody’s opened a new Ben and Jerry’s on Saturn’s icy moon Enceladus. Not yet, at least. But a new paper just published in the magazine, Icarus, shows again just how valuable the images are from the joint NASA-ESA mission Cassini, even years after the probe was intentionally crashed into Saturn. Specifically, Cassini also delivered the most detailed global infrared images ever taken of Saturn’s moon Enceladus. Combined with photos of Cassini’s other cameras, they provide convincing evidence that the northern hemisphere of the moon is covered with relatively fresh ice from its interior.

The scientists that were part of the Cassini mission discovered in 2005 that enormous geysers of ice particles and vapor are shooting out from an ocean beneath its icy crust. The new spectral map shows that infrared signals can be clearly correlated with this geological activity that can be easily seen at its south pole. There, ice and vapor from the liquid interior are being ejected out in the so-called “tiger stripes.”

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