Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: evolution – Page 50

SPECULOOS Project Discovers Earth-Sized Planet Around Ultra-Cool Star

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.”

Exploring WASP-193 b: A Cotton Candy-like Exoplanet

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.

Near-Collapse of Geomagnetic Field May Have Contributed to Diversification of Life on Earth

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.

Molecular analysis confirms T. Rex’s evolutionary link to birds

face_with_colon_three year 2008.

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.

Higgs Boson-Induced Reheating and Dark Matter Production

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.

10 Brilliant Insights from Daniel Dennett

Daniel Dennett, who died in April at the age of 82, was a towering figure in the philosophy of mind. Known for his staunch physicalist stance, he argued that minds, like bodies, are the product of evolution. He believed that we are, in a sense, machines—but astoundingly complex ones, the result of millions of years of natural selection.

Dennett wrote more than a dozen books, some of them aimed at a scholarly audience but many of them directed squarely at the inquisitive non-specialist—including bestsellers like Consciousness Explained, Breaking the Spell, and Darwin’s Dangerous Idea. Reading his works, one gets the impression of a mind jammed to the rafters with ideas. As Richard Dawkins put it in a blurb for Dennett’s last book, a memoir titled I’ve Been Thinking: “How unfair for one man to be blessed with such a torrent of stimulating thoughts.”

Study Shedding New Light on Earth’s Global Carbon Cycle could Help Assess Liveability of Other Planets

Research has uncovered important new insights into the evolution of oxygen, carbon, and other vital elements over the entire history of Earth – and it could help assess which other planets can develop life, ranging from plants to animals and humans.

The study, published today in Nature Geoscience and led by a researcher at the University of Bristol, reveals for the first time how the build up of carbon-rich rocks has accelerated oxygen production and its release into the atmosphere.

Until now the exact nature of how the atmosphere became oxygen-rich has long eluded scientists and generated conflicting explanations.

/* */