Planet Watch: January 2017

One of the most fascinating set of objects in the sky for millennia have been the planets.  Planets have been known to civilization for many thousands of years.  The term 'Planet' comes from the Ancient Greek word: planētēs, which means wanderer.  When we look at the skies today it seems as though these star-like objects do in fact wander across the sky relative to the background celestial arrangement.

In the February edition of Planet Watch we will discuss how the planets got their names.

Much to the consternation of a veritable selection of the population, Pluto is not a planet.  It is considered to be a dwarf planet.  A link to the IAU resolution is provided below:

https://www.iau.org/static/resolutions/Resolution_GA26-5-6.pdf

Excluding the Earth, there are 5(or 6) planets visible to the naked eye.  Uranus is on the cusp of naked eye visibility and can be seen with great eyes and perfect skies, certainly not achievable in any area with even the smallest amount of light pollution.

The purpose of the Planet Watch is to describe where exactly the planets are at this date and the vicinity throughout the month.  This will allow you the opportunity to see them and point them out to friends and neighbours.

Mercury

Mercury is typically the most difficult to see as it is always in the direction of morning or evening twilight.  Also, since it is always near the horizon the atmosphere generally hazes out a good viewing.

However, it is approaching its greatest elongation west (GEW) on January 19, 2017.  The greatest elongation means the planet is at its greatest angle in the sky away from the Sun.  On January 19, 2017 Mercury will be 24° from the Sun.

If you would like to attempt a sighting look toward the SE sky an hour sky chart below shows the SE sky an hour before sunrise.

Location of Mercury, Saturn and Jupiter at 07:38 January 5, 2017

Venus

Venus is the easiest planet to see in the night sky at its current position.  After sunset, look toward the S/SW sky and it will be the brightest object until it sets at 20:57.  The sky chart is provided in the image below.

Mars

Mars is also fairly easy to see.  It is just up and to the left of the easily seen Venus.  It is much dimmer, but you should be able to observe the rusty tint to it.  It will set an hour after Venus at 21:59. The sky chart is provided in the image below.

Location of Mars and Venus at 17:38 January 4, 2017

Jupiter

Jupiter is very easy to see if you stay up really late or wake up early as it appears directly South about an hour before the sun rises.  It is important to note that it is just above Alpha Virginis (also known as Spica), the 16th brightest star in the night sky.  A pair of 10x50 binoculars held steady might be enough to show the four observable Galilean Moons of Jupiter.  The sky chart is provided with Mercury above.  Provided below is a picture I took using my cell phone in an 8" reflector telescope.

Jupiter

Saturn

As discussed previously, Saturn makes its appearance about an hour before sunrise with Mercury and Antares.  The sky chart is provided with Mercury above.  Provided below is a picture I took using my cell phone in an 8" reflector telescope.

Saturn

Uranus and Neptune

Uranus and Neptune are visible only through optical instruments (see note about Uranus above).  Uranus is currently 36' SE of the star Zeta Piscium, a naked eye star from country skies.  Neptune sits about 2.75° SW of Mars in which it was in conjunction on New Year's Day.

If you are going out planet hunting I wish you the best of luck, especially with early morning Mercury (I have not seen it yet).  I'm hoping you can pull in all of the naked eye planets this month.