What makes a meteor a fireball? First of all, everyone agrees that a fireball is an exceptionally bright meteor. Past that, the International Astronomical Union defines a fireball as a meteor brighter than apparent magnitude -4, which corresponds (roughly) to being brighter than any planet — as well as bright enough to cast a human-noticeable […]
It’s only 50 light-years to 51 Pegasi. That star’s position is indicated in this snapshot from August, taken on a hazy night with mostly brighter stars visible above the dome at Observatoire de Haute-Provence in France. Twenty-six years ago, in October of 1995, astronomers Michel Mayor and Didier Queloz announced a profound discovery made at […]
This NASA/ESA Hubble Space Telescope image features two interacting galaxies that are so intertwined, they have a collective name – Arp 91. via NASA https://ift.tt/3uRoMXg
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 NGC 869 (top) and NGC 884, both clusters are about 7,000 light-years away and contain stars much younger and hotter than the […]
The seven-member Expedition 65 crew gathered for a portrait inside the International Space Station. via NASA https://ift.tt/3uXKA3y
Slide your telescope just east of the Lagoon Nebula to find this alluring field of view in the rich starfields of the constellation Sagittarius toward the central Milky Way. Of course the Lagoon nebula is also known as M8, the eighth object listed in Charles Messier’s famous catalog of bright nebulae and star clusters. Close […]
This artist’s conception illustrates a Jupiter-like planet alone in the dark of space, floating freely without a parent star. via NASA https://ift.tt/2YmNPpr
Where do the dark streams of dust in the Orion Nebula originate? This part of the Orion Molecular Cloud Complex, M43, is the often imaged but rarely mentioned neighbor of the more famous M42. M42, seen in part to the upper right, includes many bright stars from the Trapezium star cluster. M43 is itself a […]
SpaceX Cargo Dragon resupply ship is pictured as it backs away from the International Space Station. via NASA https://ift.tt/3AeeAcv
Sunrise at the South Pole is different. Usually a welcome sight, it follows months of darkness — and begins months of sunshine. At Earth’s poles, it can take weeks for the Sun to rise, in contrast with just minutes at any mid-latitude location. Sunrise at a pole is caused by the tilt of the Earth […]