July 31, 2014

Astro event: A Close Planetary Conjunction.

Mars & venus at closest conjunction. (Created by Author in Starry Night).

Mars & venus at closest conjunction. (Created by Author in Starry Night).

 

   The dusk planetary action continues this week with a close conjunction of the planets Mars and Venus. Our two nearest planetary neighbors in space have been playing a game of apparent cat and mouse in the dusk skies, approaching each other within two degrees of arc July 31st, receding, and then approaching again. Closest approach is around August 19th, when both planets are within 1° 45’ of each other as seen from our Earthly vantage point. This is one of the better planetary conjunctions of the year, and a good study in comparative planetary characteristics and orbital mechanics. [Read more...]

31.08.09: An Edge on Saturn.

Saturn's rings in darkness during the recent August 10th equinox. (Credit:NASA/JPL/Cassini Imaging Team).

Saturn's rings in darkness during the recent August 10th equinox. (Credit:NASA/JPL/Cassini Imaging Team).

A rather odd event is transpiring in the Saturnian system, one that only happens a couple of times in our lifetime; its rings are vanishing. Not really, of course; we are merely passing through the super-fine ring plane as viewed from the Earth. The exact date of the “crossing” as viewed from Earth is Friday, September 4th, when the 20 meter thick rings will be exactly edge on and vanish from all but the largest telescopes. Just a few weeks ago, Saturn passed equinox, when the rings were edge on to the Sun and hence, not illuminated across their 100,000+ km expanse. This happens every 14 to 15 years during the planet’s 29.7 year orbit. [Read more...]