Astro Blog

https://eos.org/articles/exoplanets-may-support-life-in-the-terminator-zone By lakananda Dasgupta , Eos/AGU.  Excerpt: A new study finds that the intersection between a searing dayside and a freezing nightside could be habitable. The results were presented at  AGU’s Fall Meeting 2022  and were  published recently  in  The Astrophysical Journal . The finding could widen the search for habitable planets in the universe....

https://www.fraknoi.com/astronomy/eclipsed-earth-rise-from-the-moon/ Source:    Andrew Fraknoi blog Excerpt:  On April 20, the Japanese Hakuto-R spacecraft took a remarkable image of the Earth from orbit around the Moon, showing a total eclipse of the Sun in progress near Australia. Unfortunately, the spacecraft, which would have been the first commercial mission to land on the Moon, appears to have crashed on the Moon when the controllers attempted touch down on April 25. Still, this beautiful image, showing our colorful Earth on the limb of the Moon will stand as a testament to the mission. (They are not the first to fail to land a capsule on the Moon, and they probably won’t be the last.) Click the little arrow on the side of the photo and you will be taken to a closer-up image of the Earth that shows more clearly the dark shadow of the Moon during the April 20th eclipse. That view is from DSCOVR, a climate-monitoring satellite (belonging the National Oceanic and Atmo...

https://www.nytimes.com/2023/04/25/science/mars-deimos-moon-photos.html By Jonathan O’Callaghan , The New York Times.  Excerpt: Deimos, the smaller of the two moons of Mars, might be a chip off the old block — quite literally. That’s the conclusion drawn by scientists in the United Arab Emirates, whose Hope orbiter — also called the Emirates Mars Mission and the country’s first interplanetary spacecraft — just snapped the best views of Deimos ever taken by human spacecraft. ... Mars has two irregularly shaped moons , and neither is mighty. Phobos, the larger of the two, is about 17 miles in diameter at its widest, and orbits closer to the red planet at an altitude of about 3,700 miles. Deimos is just nine miles across on its longest side, and completes an orbit of Mars every 30 hours at an altitude of 15,000 miles. The moons’ small size and quirky dimensions led to suggestions that they may be asteroids captured by Mars long ago. Not so, say researchers analyzing data recorded by H...

https://eos.org/articles/hydrogen-may-push-some-exoplanets-off-a-cliff ] By Julie Nováková , Eos/AGU.  Excerpt: With the discovery of more than 5,000 confirmed exoplanets, astronomers understand more and more about what kinds of planets exist and why. But the data deluge has also thrown into relief the kinds of planets that  don’t  seem to exist. In particular, there is a steep decrease in the abundance of planets larger than approximately 3 Earth radii, a pattern nicknamed the “ radius cliff .” ...new research published in the  Planetary Science Journal  has shown how high-pressure, high-temperature chemical reactions might put a cap on planet growth. ...Missions like NASA’s  Kepler  and  Transiting Exoplanet Survey Satellite  have revealed a curious mystery: Planets 3 times Earth’s size are about 10 times more abundant than planets that are only slightly larger. ...In a first-of-its-kind experiment, researchers placed a thin foil of pr...

https://skyandtelescope.org/astronomy-news/does-earth-have-new-quasi-moon/ By David Chandler, Sky & Telescope Magazine.  Excerpt: Recently discovered asteroid 2023 FW 13  has created a bit of a stir among asteroid watchers. It turns out to be on an orbit that is not only in a 1:1 resonance with the Earth, but follows a path that actually circles Earth — albeit on an orbit that is so eccentric that it sweeps out halfway to Mars and in halfway to Venus. There’s no formal definition for objects such as this, which are sometimes called quasi-moons or quasi-satellites. They follow a path around Earth, but usually for no more than a few decades. Perhaps the best known of these objects, known as Kamoʻoalewa, was  found in 2016 , and is considered the smallest, closest, and most stable known quasi-satellite. It has an orbit that has been in a stable resonance with Earth for almost a century, and will remain so for centuries to come, according to calculations by Paul Chodas (J...

https://www.science.org/content/article/spacecraft-explore-habitability-jupiter-s-ocean-moons By Paul Voosen, Science.  Excerpt: Ganymede, Jupiter’s largest moon, is practically a planet. Larger than Mercury, it is the only moon with its own magnetic field, produced by churning molten iron in its core. Its icy crust, more than 100 kilometers thick, ...And beneath the crust, many researchers believe, is a salty ocean, kept warm by the moon’s inner heat and Jupiter’s gravitational kneading. ...Ganymede is one of three jovian moons that may hold hidden oceans, all potential habitats for life. They are the targets of the $1.6 billion  Jupiter Icy Moons Explorer  (Juice), a European Space Agency (ESA) mission set for a 13 April launch on an Ariane 5 rocket from French Guiana. ...Juice will take 8 years to reach Jupiter. It will spend another 3 years promenading among the moons, eventually ending up in a tight orbit around Ganymede—the first time a spacecraft will orbit a moon ...