Northwest sky on Sunday at 6.30pm
While many people have never seen it, Mercury is quite easy to spot if you know where to look, writes Ian Griffin.
I am in Tekapo for what I hope will be a splendid weekend of planetary observing at the at the Mount John Observatory. For the next couple of nights, I aim to spend as much time as I can obtaining high-resolution pictures of Mars, Jupiter and Saturn using one of the 0.6m telescopes.
I am also hoping to observe Mercury during my Tekapo sojourn. After spending much of the past few months in the morning sky, the innermost planet has just started to become visible after sunset.
Over the next few weeks, it will get higher in the sky with each passing night until it reaches its greatest evening elongation from the sun on August 27.
This week, Mercury is low in the northwestern sky in the hour after sunset. It is presently moving through the constellation of Leo the Lion. While many people have never seen it, Mercury is actually quite easy to see with the unaided eye if you know where to look.
Over the next few evenings, it will move closer and closer to Regulus, which is the brightest star in Leo.
On Thursday night the star and the planet will be separated in the sky by less than 1 degree. Of course, this is just a line of sight effect; while the distance to Mercury is just 10 light minutes, Regulus is more than 79 light years from Earth.
