Astro Blog

https://www.nytimes.com/2022/09/30/science/europa-nasa-juno-photos.html By  Kenneth Chang , The New York Times.  Excerpt: Juno, a NASA spacecraft that has been orbiting Jupiter since 2016, zipped within 219 miles of Europa’s surface early on Thursday, speeding by at more than 30,000 miles per hour. Less than 12 hours later, the four images taken during the flyby, the closest observations of the moon since January 2000, were back on Earth. “They’re stunning, actually,” said Candice J. Hansen-Koharcheck, a scientist at the Planetary Science Institute in Tucson, Ariz., who is responsible for the operation of the spacecraft’s primary camera,  JunoCam . ...All four images were available  on Juno’s website .… 

https://www.nasa.gov/press-release/nasa-s-dart-mission-hits-asteroid-in-first-ever-planetary-defense-test NASA RELEASE 22-100.  Excerpt: After 10 months flying in space, NASA’s Double Asteroid Redirection Test (DART) ...successfully impacted its asteroid target on Monday, the agency’s first attempt to move an asteroid in space. Mission control at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, announced the successful impact at 7:14 p.m. EDT. As a part of NASA’s overall  planetary defense  strategy, DART’s impact with the asteroid Dimorphos demonstrates a viable mitigation technique for protecting the planet from an Earth-bound asteroid or comet, if one were discovered. ...said NASA Administrator Bill Nelson “As NASA studies the cosmos and our home planet, we’re also working to protect that home, and this international collaboration turned science fiction into science fact, demonstrating one way to protect Earth.” DART targeted the asteroid moonlet Dimorphos, a

https://www.nasa.gov/feature/goddard/2022/new-webb-image-captures-clearest-view-of-neptune-s-rings-in-decades By NASA  Laura Betz   (Goddard Space Flight Center, Greenbelt, MD), Hannah Braun and Christine Pulliam (Space Telescope Science Institute, Baltimore, MD).  Excerpt: ...Webb’s extremely stable and precise image quality permits these very faint rings to be detected so close to Neptune. ...Compared to the gas giants, Jupiter and Saturn, Neptune is much richer in elements heavier than hydrogen and helium. This is readily apparent in Neptune’s signature blue appearance in  Hubble Space Telescope images  at visible wavelengths, caused by small amounts of gaseous methane. Webb’s  Near-Infrared Camera  (NIRCam) images objects in the near-infrared range from 0.6 to 5 microns, so Neptune does not appear blue to Webb. In fact, the methane gas so strongly absorbs red and infrared light that the planet is quite dark at these near-infrared wavelengths, except where high-altitude clouds are p

https://eos.org/articles/impact-crater-off-the-african-coast-may-be-linked-to-chicxulub By  Katherine Kornei , Eos/AGU.  Excerpt: In the world of impact craters, Chicxulub is a celebrity: The 180-kilometer-diameter maw, in the Gulf of Mexico, was created by a cataclysmic asteroid impact at the end of the Cretaceous that spelled the demise of most dinosaurs. But researchers have now uncovered another crater off the coast of West Africa that might well be Chicxulub’s cousin. The newly discovered feature, albeit much smaller, is also about 66 million years old. That’s a curious coincidence, and scientists are now wondering whether the two impact structures might be linked. Perhaps Chicxulub and the newly discovered feature—dubbed Nadir crater—formed from the breakup of a parent asteroid or as part of an impact cluster, the team suggested. These results were  published in  Science Advances .… 

https://www.science.org/content/article/nasa-s-unprecedented-asteroid-deflection-mission-more-billiards-space-scientists-say By Zack Savitsky, Science Magazine.  Excerpt: On 26 September, an act of targeted violence will unfold 11 million kilometers from Earth, as a spacecraft about the size of a vending machine smashes into a small asteroid at 6 kilometers per second. Unlike some asteroids that stray worrisomely close to Earth’s orbit, Dimorphos—the 160-meter moon of a larger body—is an innocent bystander, posing no threat to our world. But the looming assault represents humanity’s first-ever field test of a planetary defense mission: NASA’s Double Asteroid Redirection Test, or DART. The hope is that the collision will nudge Dimorphos into a closer orbit around its 780-meter partner, Didymos, shortening its nearly 12-hour orbital period by a few minutes. A successful strike would support the idea that, in the future, similar efforts could deflect threatening asteroids onto safer cours

https://www.science.org/content/article/webb-telescope-takes-its-first-direct-image-exoplanet By Daniel Clery, Science Magazine.  Excerpt: A research team analyzing early data from the James Webb Space Telescope has revealed the instrument’s initial images of a planet beyond our Solar System, a success that closely follows last week’s unveiling of Webb’s first  measurements from the atmosphere of a different exoplanet . The newly imaged young gas giant, seven times the mass of Jupiter, is captured still glowing hot after its formation. The planet’s infrared emissions traveled 350 light-years before the photons were gathered by Webb’s gold-plated mirrors. In a paper  posted today on the arXiv preprint server , the Webb astronomers exhibit several images of the planet, called HIP 65426 b, at a range of wavelengths (shown in insets, above) that have heretofore been invisible to Earthbound telescopes because of our planet’s infrared-blocking atmosphere. ...the high quality of these first i