Category Astronomy/Space

Early Planetary Migration Can Explain Missing Planets

An illustration of various types of known exoplanets
An illustration of the variations among the more than 5,000 known exoplanets discovered since the 1990s. (Image courtesy of NASA/JPL-Caltech)

Model accounts for scarcity of planets with masses between super-Earths and mini-Neptunes. Computer simulations by Rice University scientists and their collaborators are the first to integrate a model of planet formation and evolution that explains two puzzling observations of exoplanets orbiting distant stars: the rarity of worlds about 1.8 times larger than Earth and the near-identical size of adjacent planets in hundreds of planetary systems.

A new model that accounts for the interplay of forces acting on newborn planets can explain two puzzling observations that have cropped up repeatedly among the more than 3,800 planetary systems catalog...

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Earth’s Oldest Stromatolites and the Search for Life on Mars

Hand sample of Dresser Formation stromatolite, showing a complex layered structure formed of hematite, barite, and quartz, and a domed upper surface (arrow).

The earliest morphological traces of life on Earth are often highly controversial, both because non-biological processes can produce relatively similar structures and because such fossils have often been subjected to advanced alteration and metamorphism. Stromatolites, layered organo-sedimentary structures reflecting complex interplays between microbial communities and their environment, have long been considered key macrofossils for life detection in ancient sedimentary rocks; however, the biological origin of ancient stromatolites has frequently been criticized...

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Oldest Planetary Debris in Our Galaxy found in New Study

Oldest planetary debris in our galaxy found from new study
Artist’s impression of the old white dwarfs WDJ2147-4035 and WDJ1922+0233 surrounded by orbiting planetary debris, which will accrete onto the stars and pollute their atmospheres. WDJ2147-4035 is extremely red and dim, while WDJ1922+0233 is unusually blue. Credit: University of Warwick/Dr Mark Garlick. Credit: University of Warwick/Dr Mark Garlick

Astronomers led by the University of Warwick have identified the oldest star in our galaxy that is accreting debris from orbiting planetesimals, making it one of the oldest rocky and icy planetary systems discovered in the Milky Way.

Their findings are published today (Nov...

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Polarized X-rays Reveal Shape, Orientation of Extremely Hot Matter around BlackHole

CygX-1 black hole
An artist’s impression of the Cygnus X-1 system, with the black hole appearing in the center and its companion star on the left. New measurements from Cygnus X-1, reported Nov. 3 in the journal Science, represent the first observations of a mass-accreting black hole from the Imaging X-Ray Polarimetry Explorer (IXPE) mission, an international collaboration between NASA and the Italian Space Agency. (Image: John Paice)

Researchers’ recent observations of a stellar-mass black hole called Cygnus X-1 reveal new details about the configuration of extremely hot matter in the region immediately surrounding the black hole.

Matter is heated to millions of degrees as it is pulled toward a black hole. This hot matter glows in X-rays...

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