Posts

Webb Captures Stellar Gymnastics in The Cartwheel Galaxy. [

https://www.nasa.gov/feature/goddard/2022/webb-captures-stellar-gymnastics-in-the-cartwheel-galaxy By  NASA, ESA, CSA, STScI .  Excerpt: NASA’s James Webb Space Telescope has peered into the chaos of the Cartwheel Galaxy, revealing new details about star formation and the galaxy’s central black hole. Webb’s powerful infrared gaze produced this detailed image of the Cartwheel and two smaller companion galaxies against a backdrop of many other galaxies. ...The Cartwheel Galaxy, located about 500 million light-years away in the Sculptor constellation, is a rare sight. Its appearance, much like that of the wheel of a wagon, is the result of an intense event – a high-speed collision between a large spiral galaxy and a smaller galaxy not visible in this image. ...The collision most notably affected the galaxy’s shape and structure. The Cartwheel Galaxy sports two rings — a bright inner ring and a surrounding, colorful ring. These two rings expand outwards from the center of the collision, li

A Unified Atmospheric Model for Uranus and Neptune

https://eos.org/research-spotlights/a-unified-atmospheric-model-for-uranus-and-neptune By  Morgan Rehnberg , Eos/AGU.  Excerpt:  In a new model, three substantial atmospheric layers appear consistent between the ice giants.  The ice giants, Uranus and Neptune, are the least understood planets in the solar system. They remain the only worlds that an orbital spacecraft has not visited. Our limited understanding of them derives largely from the flyby of NASA’s  Voyager 2  probe and subsequent observations with the  Hubble Space Telescope . Yet the ice giants may be most representative of the extrasolar planets in our local vicinity. Why these planets appear so different in color despite having very similar physical properties, including vertical temperature profile and atmospheric composition, is a mystery. Past investigations have attributed Neptune’s deeper blue largely to excess absorption in the red and near infrared from atmospheric methane. ... Irwin et al .  attempt to fill this ga

NASA Reveals Webb Telescope's First Images of Unseen Universe

https://webbtelescope.org/news/news-releases By NASA, ESA, Canadian Space Agency.  Excerpt: The first images and spectroscopic data from NASA’s James Webb Space Telescope have revealed unprecedented and detailed views of the universe. Webb’s first images and spectra, including downloadable files, can be found at  https://webbtelescope.org/news/first-images .… See zoomable image of Webb's First Deep Field (very early galaxies); Deepest Image of Universe ; Spectrum of an exoplanet ; Southern Ring Nebula (dying star); Stephan’s Quintet (merging galaxies); star-forming region NGC 3324  in the Carina Nebula; and Science Magazine article  Webb telescope wows with first images .

Webb Telescope Will Look for Signs of Life Way Out There

https://www.nytimes.com/2022/07/02/science/webb-telescope-exoplanets-atmosphere.html Source:     Carl Zimmer , The New York Times Excerpt:  The first question astronomers want to answer about exoplanets: Do they have atmospheres friendly to life? ... Identifying an atmosphere in another solar system would be remarkable enough. But there is even a chance — albeit tiny — that one of these atmospheres will offer what is known as a biosignature: a signal of life itself. ... Scientists are still debating what a reliable biosignature would be. Earth’s atmosphere is unique in our solar system in that it contains a lot of oxygen, largely the product of plants and algae. But oxygen can also be produced without life’s help, when water molecules in the air are split. Methane, likewise, can be released by living microbes but also by volcanoes.

Zhurong Rover Spots Evidence of Recent Liquid Water on Mars

https://eos.org/articles/zhurong-rover-spots-evidence-of-recent-liquid-water-on-mars ]  By Katherine Kornei , Eos/AGU.  Excerpt: Mars is hardly a verdant world today, yet evidence abounds that liquid water  once flowed over the Red Planet . Now, the latest rover to arrive on Mars’s surface—Zhurong, part of China’s  Tianwen-1 mission —has spotted hydrated minerals that point to liquid water persisting well into the Red Planet’s most recent geologic period. These results,  published in  Science Advances , contribute to our understanding of when liquid water flowed on Mars, the research team has suggested.…

Why Did Sunspots Disappear for 70 Years? Nearby Star Holds Clues

https://eos.org/articles/why-did-sunspots-disappear-for-70-years-nearby-star-holds-clues By Kimberly M. S. Cartier , Eos/AGU. Excerpt: Every 11 years, the number of spots dotting the surface of the Sun increases and decreases like clockwork. Astronomers have been tracking the 11-year sunspot cycle for more than 400 years, using it to better understand the chaotic magnetic field the Sun puts out. (The current solar cycle, number 25, started in 2019.) The timing of the solar cycle is remarkably consistent: Sunspot numbers rise and fall, rise and fall…except for that time that they disappeared and weren’t seen again for 70 years. That period of time, from 1645 to 1715, is known as the  Maunder Minimum , named after 19th century British astronomers Edward and Annie Maunder. Astronomers still don’t understand why the Sun ceased making sunspots for 70 years, but a new analysis of more than 5 decades of measurements of nearby stars has identified one that might be undergoing its own Maunder-l

Astronomers may have detected a ‘dark’ free-floating black hole

https://news.berkeley.edu/2022/06/10/astronomers-may-have-detected-a-dark-free-floating-black-hole/ By Robert Sanders , UC Berkeley News.  Excerpt: If, as astronomers believe, the death of large stars leave behind black holes, there should be hundreds of millions of them scattered throughout the Milky Way galaxy. The problem is, isolated black holes are invisible. Now, a team led by University of California, Berkeley, astronomers has for the first time discovered what may be a free-floating black hole by observing the brightening of a more distant star as its light was distorted by the object’s strong gravitational field — so-called gravitational microlensing. The team, led by graduate student Casey Lam and  Jessica Lu , a UC Berkeley associate professor of astronomy, estimates that the mass of the invisible compact object is between 1.6 and 4.4 times that of the sun. Because astronomers think that the leftover remnant of a dead star must be heavier than 2.2 solar masses in order to co