Items tagged with: astronomy
M106: A Spiral Galaxy with a Strange Center
Image Credit: NASA, ESO , NAOJ, Giovanni Paglioli; Assembling and Processing: R. Colombari and R. Gendler
Explanation: What's happening at the center of spiral galaxy #M106? A swirling disk of stars and gas, M106's appearance is dominated by blue spiral arms and red dust lanes near the nucleus, as shown in the featured image. The core of M106 glows brightly in radio waves and X-rays where twin jets have been found running the length of the galaxy. An unusual central glow makes M106 one of the closest examples of the Seyfert class of galaxies, where vast amounts of glowing gas are thought to be falling into a central massive black hole. M106, also designated #NGC4258, is a relatively close 23.5 million light years away, spans 60 thousand light years across, and can be seen with a small telescope towards the constellation of the Hunting Dogs (Canes Venatici).
#astrophotography #astronomy #space #APOD #galaxy
Who really is the earth's closes neighbour?
As it turns out, by some phenomenon of carelessness, ambiguity, or groupthink, science popularizers have disseminated information based on a flawed assumption about the average distance between planets. Using a mathematical method that we devised, we determine that when averaged over time, Earth’s nearest neighbor is in fact Mercury.
By using a more accurate method for estimating the average distance between two orbiting bodies, we find that this distance is proportional to the relative radius of the inner orbit. In other words, Mercury is closer to Earth, on average, than Venus is because it orbits the Sun more closely. Further, Mercury is the closest neighbor, on average, to each of the other seven planets in the solar system.
For two bodies with roughly coplanar, concentric, circular orbits, the average distance between the two bodies decreases as the radius of the inner orbit decreases. It’s clear from this corollary, and from the table, that Mercury (average orbital radius of 0.39 AU), not Venus (average radius of 0.72 AU), is the closest planet to Earth on average. In fact, Mercury is even the closest planet to Neptune. (And yes, to Pluto too: Though the corollary doesn’t work as well for the dwarf planet, with its orbital inclination of 17° and eccentricity of 0.25, its nearest neighbor is also Mercury.)
#Science #Astronomy #PlanetarySystem #News #Mercury #Venus #Earth
APOD: 2003 June 24 - The Sun's Surface in 3D
How smooth is the Sun? The new Swedish 1-m Solar Telescope, deployed in the Canary Islands only last year, allows imaging of objects less than 100-km across on the Sun's surface. When pointed toward the Sun's edge, surface objects now begin to block each other, indicating true three-dimensional information. Close inspection of the image reveals much vertical information, including spectacular light-bridges rising nearly 500-km above the floor of sunspots near the top of the image. Also visible in the above false-color image are hundreds of bubbling granules, each about 1000-km across, and small bright regions known as faculas.
#astronomy #picture #space #NASA #APOD