July 27, 2017

Mercury-Spotting during the First Elongation of 2013.

Mercury as seen by Messenger during its

3rd flyby in 2009.

(Credit: NASA/JPL).

I SEE IT! Catching a glimpse of fleeting Mercury can be an unforgettable experience; orbiting the Sun once every 88 days, the innermost planet never strays far from its perch low in the dawn or dusk sky. February offers your first shot at catching the world low in the dusk as it approaches its first of six elongations in 2013. Though not the best of 2013 for most viewers worldwide (see below), this month’s elongation does offer roughly equal prospects for both northern and southern hemisphere observers as the ecliptic approaches near-perpendicular to the horizon headed towards the March equinox. And as you’ll see, this apparition will set us up for some of the best prospects for catching Mercury later this spring. [Read more...]

Astro-Event: A Spectacular Dawn Appulse.

Venus versus Regulus: the view on October 3rd.

(All simulations created by the Author in Starry Night).

It’s a question we have posed before, worthy of a sequel to Arthur Upgreen’s alternate astronomy book Many Skies; what would Venus look like if it had a moon? As a kid, I remember a science book on the solar system looking back at the Earth-Moon system from Venus, assuming that you could get above the cloud tops. At greatest elongation, Earth’s Moon would be 9’ arc minutes from the planet’s -3.6 magnitude disk this month and would itself shine at +0.5 magnitude… what a view that would be! [Read more...]

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...]