Astro Blog

By Leah Crane , NewScientist.  Excerpt: Astronomers have found six new worlds that look like planets, but formed like stars. These so-called rogue worlds are between five and 15 times the mass of Jupiter, and one of them may even host the beginnings of a miniature solar system. ...From their observations, the researchers determined that planetary mass  brown dwarfs  make up about 10 per cent of the objects in NGC 1333. That is far more than expected based on models of star formation, so there may be extra processes, such as turbulence, that drive the formation of these rogue worlds. ...One of the brown dwarfs is particularly unusual – it has a ring of dust around it just like the one that formed the planets in our solar system. At about five Jupiter masses, it is  the smallest world  ever spotted with such a ring, and it may mark the beginnings of a strange, scaled-down planetary system around a failed star... .  Full article at https://www.newscientist.com/article/2445279-jwst-found-r

By Vashan Wright ,  Matthias Morzfeld , and  Michael Manga , PNAS - Proceedings of the National Academy of Sciences.  Abstract: Large volumes of liquid water transiently existed on the surface of Mars more than 3 billion years ago. Much of this water is hypothesized to have been sequestered in the subsurface or lost to space. We use rock physics models and Bayesian inversion to identify combinations of lithology, liquid water saturation, porosity, and pore shape consistent with the constrained mid-crust (∼11.5 to 20 km depths) seismic velocities and gravity near the InSight lander. A mid-crust composed of fractured igneous rocks saturated with liquid water best explains the existing data. Our results have implications for understanding Mars’ water cycle, determining the fates of past surface water, searching for past or extant life, and assessing in situ resource utilization for future missions.  Full article at https://www.pnas.org/doi/10.1073/pnas.2409983121 . 

By Daniel Clery , Science.  Excerpt: For years, astronomers thought it was the Milky Way’s destiny to collide with its near neighbor the Andromeda galaxy a few billion years from now. But a new simulation finds a 50% chance the impending crunch will end up a near-miss, at least for the next 10 billion years. ...It’s been known that Andromeda is heading toward our home Galaxy since 1912, when astronomer Vesto Slipher noted that its light is blue-shifted.... ...It wasn’t until the era of orbiting observatories that astronomers could judge Andromeda’s overall velocity in 3D.... It was, they calculated, heading pretty much straight at the Milky Way at a speed of 110 kilometers per second. ...A  study from 2008  suggested a Milky Way–Andromeda merger was inevitable within the next 5 billion years...ending up in...the resulting elliptical, which the researchers dub “Milkomeda.” The Milky Way, seen today as a bright band across the sky, would be replaced by a “milky blob” marking the dense co

By Hannah Richter , Science.  Excerpt: One of the classic tropes of science fiction is  terraforming Mars : warming up our cold neighbor so it could support human civilization. The idea might not be so far-fetched,  research published today  in Science Advances suggests. Injecting tiny particles into Mars’s atmosphere could warm the planet by more than 10°C in a matter of months, researchers find—enough to sustain liquid water. Although the scheme would require about 2 million tons of particles per year, they could be manufactured from readily available ingredients found in martian dust....  Full article at https://www.science.org/content/article/terraforming-mars-could-be-easier-scientists-thought .