Astro Blog

https://www.science.org/content/article/giant-plume-spotted-erupting-moon-saturn-might-contain-ingredients-life By Ron Cowen, Science.  Excerpt: NASA’s JWST space telescope has observed a 10,000-kilometer-long plume of water vapor jetting into space from Saturn’s moon Enceladus—the largest spray ever detected from the icy world, which is just one-seventh the diameter of Earth’s Moon. ...Planetary scientists view Enceladus as a prime target in the search for extraterrestrial life because beneath its icy crust the moon houses a salty ocean—a good medium for the ingredients of life to mix. ...Researchers describe the results  today in a NASA press release  and in a  paper  accepted at Nature Astronomy. ...NASA’s Cassini mission, which in 2005 discovered the plumes on Enceladus  ... flew through them  seven times during its 13-year mission, discovering organic molecules such as methane and formaldehyde, and hydrogen, a potential energy source for microbes.... 

https://www.fraknoi.com/astronomy/a-star-blows-up-in-nearby-galaxy/ By Andrew Fraknoi.  Excerpt: In a galaxy not so “far, far away,” called the Pinwheel Galaxy (or by its catalog number, M101,) astronomers have seen a star explode. Some 21 million lightyears from us — which, believe it or not, is “close” as far as astronomers are concerned — a massive star ended its life by blowing most of itself into smithereens. We call such an explosion a  supernova,  a word that has entered popular culture as the name of at least five movies and a jazz album. This supernova was only discovered on May 19th, and is still getting brighter and brighter. Some of these explosions can become so bright that they outshine their entire galaxy. We’ll have to see how bright this one gets. ...Our best estimates are that the star that blew up had enough material in it to make 15 of our Suns. ...We estimate that one such supernova goes off in a galaxy like our Milky Way once every 50-75 years. But M101 is a bigge

https://www.nytimes.com/2023/05/12/science/saturn-moons-jupiter.html By Jonathan O’Callaghan , The New York Times.  Excerpt: This month, the International Astronomical Union is set to recognize 62 additional  moons of Saturn  based on a batch of objects discovered by astronomers. The small objects will give Saturn 145 moons — eclipsing Jupiter’s total of 95. ...The growing number of moons also highlights potential debates over what constitutes a moon. “The simple definition of a moon is that it’s an object that orbits a planet,” Dr. Sheppard said. An object’s size, for the moment, doesn’t matter. ...In March, Dr. Sheppard was also responsible for finding  12 new moons of Jupiter , which took it temporarily above Saturn in the scuffle to be the biggest hoarder of moons. That record was short-lived, it seems....

https://www.nasa.gov/feature/goddard/2023/webb-looks-for-fomalhaut-s-asteroid-belt-and-finds-much-more By NASA.  Excerpt: Astronomers used NASA’s James Webb Space Telescope to image the warm dust around a nearby young star, Fomalhaut, in order to study the first asteroid belt ever seen outside of our solar system in infrared light. But to their surprise, the dusty structures are much more complex than the asteroid and Kuiper dust belts of our solar system. Overall, there are three nested belts extending out to 14 billion miles (23 billion kilometers) from the star; that’s 150 times the distance of Earth from the Sun. The scale of the outermost belt is roughly twice the scale of our solar system’s Kuiper Belt of small bodies and cold dust beyond Neptune. The inner belts – which had never been seen before – were revealed by Webb for the first time. ...The team’s results are being published in the journal  Nature Astronomy . See also  New York Times article .... 

https://skyandtelescope.org/astronomy-news/four-of-uranuss-moons-might-contain-briny-oceans/ By Emily Lakdawala, Sky & Telescope.  Excerpt: A  new paper re-analyzing Voyager observations  suggests that four of Uranus’ five icy satellites also host oceans: Ariel, Umbriel, Titania, and Oberon. (Only small Miranda, intermediate in size between Saturn’s Mimas and Enceladus, appears not to.) The oceans are desperately thin: less than 30 kilometers (20 miles) thick inside Ariel and Umbriel (both of which are about 1,000 kilometers across, similar in size to Saturn’s Tethys and Dione), and less than 50 kilometers thick within Titania and Oberon (which are larger at about 1,500 kilometers, similar to Saturn’s Rhea and Iapetus). If the oceans exist, they would be left over from much larger liquid layers that formed when the moons first formed. ...They’d be extremely briny, hyper-concentrated with whatever dissolved materials helped to lower the temperature at which water would otherwise fre

https://skyandtelescope.org/astronomy-news/star-caught-swallowing-a-planet/ By Camille M. Carlisle, Sky & Telescope.  Excerpt: For the first time, astronomers have witnessed a star eat an exoplanet. The dinner bell has struck for a star in the constellation Aquila, the Eagle. Reporting in the May 4th  Nature , Kishalay De (MIT) and a team of astronomers watched the star belch and brighten in a way that suggests  it swallowed a closely orbiting planet . The star in question is a nondescript Sun-like star about 12,000 light-years away. Pre-outburst observations indicate it was slightly bloated, perhaps twice as wide as the Sun, and entering its golden years. This time in a star’s life can be a dangerous one for planets. As the star finishes fusing the hydrogen in its core, it brightens and swells. Eventually, it can swell enough to engulf the closest worlds, destroying them in a fiery furnace..... See also Science article  A dying star consumes a planet, foreshadowing Earth’s fate [