Astro Blog

https://eos.org/articles/mercury-isnt-alone-in-orbit-and-scientists-dont-know-why By Jure Japelj , Eos/AGU.  Excerpt: A cloud of dust traces the innermost planet’s orbital path. By all accounts, it shouldn’t be there. ...In a new study  published  in the  Planetary Science Journal,  scientists tried to trace the genesis of Mercury’s dust. And although they still don’t know how this improbable cloud formed, they do know that it probably has a different origin story than the one escorting our own planet. ...Earth’s dust ring formed from the immense cloud of dust, called a zodiacal or interplanetary dust cloud, that pervades the space between planets. ...Earth and Venus are massive enough to stall migrating dust, but Mercury is not. That close to the Sun, phenomena including solar winds, solar light, and strong magnetic fields should, quite literally, kick the dust up, and Mercury isn’t large enough to trap the celestial debris in its gravitational pull. ...Using ...

https://www.theguardian.com/science/2023/feb/22/universe-breakers-james-webb-telescope-detects-six-ancient-galaxies By Hannah Devlin , The Guardian.  Excerpt: The  James Webb space telescope  has detected what appear to be six massive ancient galaxies, which astronomers are calling “universe breakers” because their existence could upend current theories of cosmology. The objects date to a time when the universe was just 3% of its current age and are far larger than was presumed possible for galaxies so early after the big bang. If confirmed, the findings would call into question scientists’ understanding of how the earliest galaxies formed....

https://www.nytimes.com/2023/02/16/science/auroras-jupiter-moons.html By Robin George Andrews , The New York Times.  Excerpt: New research shows auroras can also be seen on the Galilean moons of Jupiter:  hypervolcanic Io ,  icy Europa , quirky Callisto and  gigantic Ganymede . ...other than  Ganymede , the big moons of Jupiter lack magnetic bubbles. Instead, their auroras owe their existence to Io. Its noxious atmosphere — partly supplied by the moon’s  epic volcanic eruptions  — regularly sheds into space. The castoffs mingle with sunlight and become electrically excited. Plenty gets captured by  Jupiter’s colossal magnetic bubble , but some of it slams back into Io’s atmosphere, or into the other three moons’ gassy sheaths. Those impacts are what ignite the moons’ auroral lights....

https://eos.org/articles/wind-could-power-future-settlements-on-mars By Alakananda Dasgupta , Eos/AGU.  Excerpt: Using a sophisticated global climate model adapted to Mars, space scientists explore the hidden potential of wind energy on the Red Planet. ...there’s the question of where to find a viable and steady source of energy that would be required for any  human mission to Mars . The answer to that question may be blowing in the Martian wind, according to a new study. ...with the atmospheric density of Mars being 1% that of Earth, much larger turbine blades would be needed to generate sufficient energy. ...Now, a study published in  Nature Astronomy  has suggested that wind energy could, indeed, be harnessed to power human settlements on Mars. “We were excited to find that there are many locations across the planet where winds are strong enough to provide a really stable power resource” and compensate for a shortfall in solar power using wind turbines, said...

https://www.nytimes.com/2023/02/08/science/quaoar-rings-roche-limit.html By Kenneth Chang , The New York Times.  Excerpt: Quaoar, which orbits the sun in the distant Kuiper belt, is the latest small object shown to have a ring like the ones around Saturn. ...Quaoar (pronounced KWA-wahr ...is a little less than half the diameter of Pluto and about a third of the diameter of Earth’s moon. It is likely to be big enough to  qualify as a dwarf planet , pulled by its gravity into a round shape. ...The ring is not visible in telescope images. Rather, astronomers found it indirectly, when distant stars happened to pass behind Quaoar, blocking the starlight. From 2018 through 2021, Quaoar passed in front of four stars, and astronomers on Earth were able to observe the shadow of the eclipses, also known as stellar occultations. However, they also observed some dimming of the starlight before and after the star blinked out. That pointed to a ring obscuring part of the light, an inte...