2023年7月8日 Stickney Crater Image Credit: HiRISE, MRO, LPL (U. Arizona), NASA Explanation: Stickney Crater, the largest crater on the martian moon Phobos, is named for Chloe Angeline Stickney Hall, mathematician and wife of astronomer Asaph Hall. Asaph Hall discovered both the Red Planet’s moons […]
2023年7月7日 The Double Cluster in Perseus Image Credit & Copyright: Mårten Frosth Explanation: This pretty starfield spans about three full moons (1.5 degrees) across the heroic northern constellation of Perseus. It holds the famous pair of open star clusters, h and Chi Persei. Also cataloged as
2023年7月5日 A Map of the Observable Universe Image Credit & Copyright: B. Ménard & N. Shtarkman; Data: SDSS, Planck, JHU, Sloan, NASA, ESA Explanation: What if you could see out to the edge of the observable universe? You would see galaxies, galaxies, galaxies, and then, well, quasars, which
2023年7月4日 Aurora over Icelandic Waterfall Image Credit & Copyright: Cari Letelier Explanation: It seemed like the sky exploded. The original idea was to photograph an aurora over a waterfall. After waiting for hours under opaque clouds, though, hope was running out. Others left. Then, unexpecte
2023年7月3日 Venus in Ultraviolet from Akatsuki Image Credit & Copyright: JAXA, Planet-C Project Team; h/t: Mehmet Hakan Özsaraç Explanation: Why is Venus so different from Earth? To help find out, Japan launched the robotic Akatsuki spacecraft which entered orbit around Venus late in 2015 after a
2023年7月2日 Milky Way and Aurora over Antarctica Image Credit & Copyright: LI Hang Explanation: It was one of the better skies of this long night. In parts of Antarctica, not only is it winter, but the Sun can spend weeks below the horizon. At China‘s Zhongshan Station, people sometimes ven
2023年7月1日 Three Galaxies in Draco Image Credit & Copyright: David Vernet, Jean-François Bax, Serge Brunier, OCA/C2PU Explanation: This tantalizing trio of galaxies sometimes called the Draco Group, is located in the northern constellation of (you guessed it) Draco, the Dragon. From left to righ
2023年6月30日 Orbits of Potentially Hazardous Asteroids Illustration Credit: NASA, JPL-Caltech Explanation: Are asteroids dangerous? Some are, but the likelihood of a dangerous asteroid striking the Earth during any given year is low. Because some past mass extinction events have been linked to asteroi
2023年6月29日 A Message from the Gravitational Universe Illustration Credit: NANOGrav Physics Frontier Center; Text: Natalia Lewandowska (SUNY Oswego) Explanation: Monitoring 68 pulsars with very large radio telescopes, the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) has unc
