Ask Astro : Does dark energy create the voids between galaxy clusters? Looking for galaxies in all the wrong places. Capturing the cosmos: How to be an astrophotographer. Sky This Month : November Chiricahua Astronomy Complex: An observing mecca for amateurs. Neutron stars: A cosmic gold mine. Ask Astro : Can a black hole form without a parent star? Cosmos: Origin and Fate of the Universe. Astronomy's Moon Globe. Galaxies by David Eicher. Astronomy Puzzles.
Jon Lomberg Milky Way Posters. Astronomy for Kids. Want to leave a comment? Only registered members of Astronomy. Registration is FREE and only takes a couple minutes. Login or Register now. Most recent Oldest to newest. At its nearest, it appears the largest in the sky of all the planets; at its most distant, numerous other planets can appear larger. However, Venus is always the brightest.
The multiple thick layers of sulfuric acid clouds play a tremendous role in pushing Venus to its extremes. This cloud cover winds up playing a vital role in the brightness of Venus as seen from Earth as well.
The Soviet Union's series of Venera landers are the only spacecraft to ever land and transmit data The longest-lived of all the landers exceeded the two-hour mark before the instruments overheated and contact was lost. To date, no spacecraft has survived for longer on the Venusian surface, where temperatures reach degrees Fahrenheit C.
Saturn is many times fainter than Jupiter, despite being almost the same size and nearly the same reflectivity: a function of its much greater distance both from the Sun and from Earth. Venus, meanwhile, is 63, times brighter than the faintest planet, Neptune. This is where things start to get interesting.
There are two types of albedo that scientists talk about:. Bond albedo , which is the ratio of the total reflected radiation compared to the total incoming solar radiation, and. Geometric albedo , which is how much light actually gets reflected compared to a flat, ideally reflective surface.
By both measures, Venus is by far the most reflective planet in the Solar System, with albedos that are each more than double the next closest planet. This high level of reflectivity makes it appear intrinsically brighter than any other planet in the Solar System, with only a few ice-rich moons, like Saturn's Enceladus, possessing a higher total albedo.
The phases of Venus, as viewed from Earth, can enable us to understand how Venus always appears from Reaching a maximum elongation of 47 degrees away from the Sun, Venus is at its largest and brightest in the thin crescent phase, but when it's more distant and smaller, it's fuller, remaining the brightest object, other than the Moon, in Earth's night sky.
On this date, the clock hour from 1 a. The mnemonic is: "Spring Ahead, Fall Back. Mercury — enjoys its very best morning apparition of this month. Each morning thereafter it rises a couple of minutes earlier, climbs noticeably higher and also gets noticeably brighter. On Nov. For several mornings both before and after this date, Mercury will appear to rise prior to the onset of twilight, in a dark sky, about 1 hour 45 minutes before sunup. At a brilliant magnitude of At around 5 a. After greatest elongation, Mercury will slide rapidly back toward the sun.
By the 24th it's again rising about 75 minutes before sunrise, but still should be bright enough You are commenting using your WordPress. You are commenting using your Google account. You are commenting using your Twitter account. You are commenting using your Facebook account. Notify me of new comments via email. Notify me of new posts via email. This site uses Akismet to reduce spam. Learn how your comment data is processed.
Skip to content Anyone, even the most casual observer, looking at the evening sky in the last month will have noticed the brilliant white planet Venus shining in the west. The Intensity, which is the amount of radiated power falling on a unit area, falls as the square of the distance Clearly the more radiation falling on a planet the brighter it is, all other factors being equal.
This depends on: the diameter of the planet — factor 3A, its distance from Earth — factor 3B and its phase i. Examples of phase for the Moon The way that these three factors interplay to make Venus the brightest object in the sky is best illustrated if we take the examples of the three brightest planets Venus, Mars and Jupiter. And finally… I hope you have enjoyed reading this post and have plenty of clear skies to observe Venus in these difficult times, when many of my readers are having to remain at home due to corona virus.
Notes on Magnitude When discussing the brightness of objects in the sky, astronomers use a scale called magnitude, where the lower the magnitude the brighter the object.
In the standardised scale for example a bright star having magnitude 1 is 9 times brighter than a star of magnitude 4. This is because 2. Like this: Like Loading Published by Steve Hurley. Next Post Staying on the Moon.
Excellent, many thanks. A very nice article, I read it with much pleasure. Lokking forward to following posts! Sorry, have to correct myself, I meant phase Also with the closest Mars opposition does it occupy a larger apparent image size than does Venus when Venus is at its brightest Venus of course then being a crescent rather than a round image like Mars at opposition Like Liked by 1 person. Some Interesting questions. Yes, the weather conditions on Mars, can affect its albedo. Thank you for taking time to share such insightful information.
Thank you for your kind comments Like Liked by 1 person. Venus bright? Mars admired her looks anyhow. Likewise near Peterborough!
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