北极星与ZTF彗星的迹线

北极星与ZTF彗星的迹线

ByNASA中文

2023年2月3日 Polaris and the Trail of Comet ZTF Image Credit & Copyright: David Ibarra Gomez Explanation: Stars trace concentric arcs around the North Celestial Pole in this three hour long night sky composite, recorded with a digital camera fixed to a tripod on January 31, near Àger, Lleida, Spain. On that date Comet C/2022 E3 (ZTF) was near its northernmost declination in planet Earth’s sky. That put the comet about 10 degrees from Earth’s North Celestial Pole making the comet’s position circumpolar, always above the horizon, from all locations on planet Earth at more than 10 degrees northern latitude. In the startrail image, the extension of Earth’s axis of rotation into space is at the left. North star Polaris traces the short, bright, concentric arc…

北天极与古树

北天极与古树

ByNASA中文

2022年7月28日 North Celestial Tree Image Credit & Copyright: Jeff Dai (TWAN) Explanation: An ancient tree seems to reach out and touch Earth’s North Celestial Pole in this well-planned night skyscape. Consecutive exposures for the timelapse composition were recorded with a camera fixed to a tripod in the Yiwu Desert Poplar Forests in northwest Xinjiang, China. The graceful star trail arcs reflect Earth’s daily rotation around its axis. By extension, the axis of rotation leads to the center of the concentric arcs in the night sky. Known as the North Star, bright star Polaris is a friend to northern hemisphere night sky photographers and celestial navigators alike. That’s because Polaris lies very close to the North Celestial Pole on the sky. Of course it can be…

扎根于旋转行星

扎根于旋转行星

ByNASA中文

2022年7月8日 Roots on a Rotating Planet Image Credit & Copyright: Marcella Giulia Pace Explanation: With roots on a rotating planet, an old tree is centered in this sequence of 137 exposures each 20 seconds long, recorded one night from northern Sicily. Digital camera and fisheye lens were fixed to a tripod to capture the dramatic timelapse, so the stars trailed through the region’s dark sky. Of course that makes it easy to spot the planet’s north celestial pole. The extension of Earth’s axis of rotation into space is toward the upper left, at the center of the concentric star trail arcs. The Milky Way is there too. The plane of our galaxy stretches across the wide field of view from north to east (left to…

风车与星像迹线

风车与星像迹线

ByNASA中文

2020 April 17 The Windmill and the Star Trails Image Credit & Copyright: Antonio Gonzalez Explanation: Stars can’t turn these old wooden arms, but it does look like they might in this scene from a rotating planet. The well-composed night skyscape was recorded from Garafia, a municipality on the island of La Palma, Canary Islands, planet Earth. The center of the once working windmill, retired since 1953, is lined-up with the north celestial pole, the planet’s rotation axis projected on to the northern sky. From a camera fixed to a tripod, the star trails are a reflection of the planet’s rotation traced in a digital composite of 39 sequential exposures each 25 seconds long. Brought out by highlighting the final exposure in the sequence, the…

红色行星的星迹

红色行星的星迹

ByNASA中文

2019 November 30 Star Trails for a Red Planet Image Credit & Copyright: Dengyi Huang Explanation: Does Mars have a north star? In long exposures of Earth’s night sky, star trails make concentric arcs around the north celestial pole, the direction of our fair planet’s axis of rotation. Bright star Polaris is presently the Earth’s North Star, close on the sky to Earth’s north celestial pole. But long exposures on Mars show star trails too, concentric arcs about a celestial pole determined by Mars’ axis of rotation. Tilted like planet Earth’s, the martian axis of rotation points in a different direction in space though. It points to a place on the sky between stars in Cygnus and Cepheus with no bright star comparable to Earth’s…