Humans are arguably the most peculiar species that has ever existed.
Acknowledging the unique aspects of human evolution underscores our extraordinary place in the grander scheme—a species with one foot in the natural world and the other in a realm of conscious self-awareness and purpose. This dual heritage suggests„.
The discovery could help better understand the origin and evolution of magnetic fields in the cosmos, a mystery that has baffled astronomers for decades.
Related: Scientists reveal never-before-seen map of the Milky Way’s central engine (image)
The new study was led by National Astronomical Observatories of the Chinese Academy of Sciences (NAOC) scientists Xu Jun and Han Jinlin.
SPECULOOS-3 b is practically the same size as our planet,” said Dr. Michaël Gillon. “A year, i.e. an orbit around the star, lasts around 17 hours. Days and nights, on the other hand, should never end.
What types of exoplanets can dwarf stars possess? This is what a recent study published in Nature Astronomy hopes to address as a team of international researchers announced the discovery of SPECULOOS 3 b, which is an Earth-sized exoplanet located approximately 55 light-years from Earth orbiting an ultra-cool dwarf star. What makes this study unique is astronomers know very little about dwarf stars and the exoplanets that could potentially orbit them, despite the number of dwarf stars outnumbering Sun-like stars throughout the cosmos. This study holds the potential to help astronomers better understand the formation and evolution of exoplanets around smaller stars and what the implications for finding life beyond Earth.
“SPECULOOS-3 b is practically the same size as our planet,” said Dr. Michaël Gillon, who is a professor at the University of Liège and first author of the study. “A year, i.e. an orbit around the star, lasts around 17 hours. Days and nights, on the other hand, should never end. We believe that the planet rotates synchronously, so that the same side, called the day side, always faces the star, just like the Moon does for the Earth. On the other hand, the night side hand, would be locked in endless darkness.”
WASP-193 b is the second least dense planet discovered to date, after Kepler-51 d, which is much smaller,” said Dr. Khalid Barkaoui. “Its extremely low density makes it a real anomaly among the more than five thousand exoplanets discovered to date.
Can gas giant exoplanets larger than Jupiter have less density than the latter? This is what study published today in Nature Astronomy hopes to address as a team of international researchers discovered WASP-193 b in 2023, which is located just under 1,200 light-years from Earth and orbits its parent star (slightly larger than our Sun) in only 6.25 days. What’s unique about WASP-193 b is that it exhibits a radius almost 1.5 times that of Jupiter, the largest planet in our solar system, but whose mass is only 14 percent of Jupiter and whose density is just under 4 percent of Jupiter, as well. This study holds the potential to help astronomers better understand the formation and evolution of exoplanets, which continue to challenge our understanding of solar system architecture.
WASP-193 b has a density of approximately 0.059 grams per centimeter cubed (g/cm3), which is comparable to cotton candy. For context, Jupiter has a density of 1.33 g/cm3, Saturn has a density of 0.69 g/cm3, Uranus has a density of 1.27 g/cm3, and Neptune has a density of 1.64 g/cm3. Therefore, despite being larger than Jupiter, WASP-193b’s density is far less than the largest gas giant in our solar system.
A recent study suggests that the near-collapse of the geomagnetic field during the Ediacaran period may have played a role in the diversification of life on Earth. This coincided with a significant increase in oxygen levels, which could have provided a favorable environment for the development of new species. The ultra-weak geomagnetic field may have allowed for increased solar radiation, leading to higher oxygen production through photosynthesis. This discovery sheds light on the potential impact of Earth’s magnetic field on the evolution of life.
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Putting more meat on the theory that dinosaurs’ closest living relatives are modern-day birds, molecular analysis of a shred of 68-million-year-old Tyrannosaurus rex protein — along with that of 21 modern species — confirms that dinosaurs share common ancestry with chickens, ostriches, and to a lesser extent, alligators.
The work, published this week in the journal Science, represents the first use of molecular data to place a non-avian dinosaur in a phylogenetic tree that traces the evolution of species. The scientists also report that similar analysis of 160,000-to 600,000-year-old collagen protein sequences derived from mastodon bone establishes a close phylogenetic relationship between that extinct species and modern elephants.
“These results match predictions made from skeletal anatomy, providing the first molecular evidence for the evolutionary relationships of a non-avian dinosaur,” says co-author Chris Organ, a postdoctoral researcher in organismic and evolutionary biology at Harvard University.
We discuss a perturbative and non-instantaneous reheating model, adopting a generic post-inflationary scenario with an equation of state w. In particular, we explore the Higgs boson-induced reheating, assuming that it is achieved through a cubic inflaton-Higgs coupling ϕ|H|2. In the presence of such coupling, the Higgs doublet acquires a ϕ-dependent mass and a non-trivial vacuum–expectation–value that oscillates in time and breaks the Standard Model gauge symmetry. Furthermore, we demonstrate that the non-standard cosmologies and the inflaton-induced mass of the Higgs field modify the radiation production during the reheating period. This, in turn, affects the evolution of a thermal bath temperature, which has remarkable consequences for the ultraviolet freeze-in dark matter production.