Moon Passes Mars

   Over the next 2 evenings, Wednesday October 17th and Thursday the 18th the waxing gibbous Moon will be passing the planet Mars coming within about 2-3o from Mars.


   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.


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It’s the Autumn Equinox on Mars

   Tuesday May 22nd is the autumnal equinox on the planet Mars as the planet transitions from summer during its 684 Earth day orbit around the Sun.
   Seasons on Mars are marked by the planet’s heliocentric longitude coordinates using the position of Mars along its orbit around the Sun. At the Martian spring equinox Mars is at 0o longitude.
   Each seasonal start/ending point is 90 degrees apart, but because of an elliptical-shaped orbit each Martian season is of varying lengths. Mars is at its greatest distance from the Sun, aphelion, before it reaches the Martian summer solstice when Mars is at 70o longitude. Perihelion, its closest to the Sun, is when Mars is at 250o longitude.
   Eccentricity of Mars and Earth for comparison.
Mars: 0.0934 – Earth: 0.0167

   I’m not exactly sure why this particular date is used but by international agreement astronomers have selected 11 April, 1955 as 0 degrees for year 1 of this Martian calendar. What this means is that on Tuesday May 22nd, Earth time, it is the start of autumn of year 34 using the aforementioned calendar system.

Year 34
0 degrees — Spring Equinox — May 05 2017
90 degrees — Summer solstice — November 20 2017
180 degrees — Fall Equinox — May 22 2018
270 degrees — Winter Solstice — October 16 2018

Year 35
0 degrees — Spring Equinox — March 23 2019
90 degrees — Summer solstice — October 08 2019
180 degrees — Fall Equinox — April 08 2020
270 degrees — Winter Solstice — September 02 2020

Year 36
0 degrees — Spring Equinox — February 07 2021
90 degrees — Summer solstice — August 25 2021
180 degrees — Fall Equinox — February 24 2022
270 degrees — Winter Solstice — July 21 2022

   Learn a little (or a lot) more about the exploration of Mars at the NASA Journey to Mars web site.

   Learn a little (or a lot) more about Mars at the NASA/JPL Mars Curiosity mission web site.
   Or read about the InSight mission currently on its way to Mars.

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to go to bobs-spaces.

2016 Martian Winter Solstice

A Martian Year

A Martian Year – at One Earth Month Intervals

   Monday November 28th is the winter solstice on the planet Mars as the planet transitions from autumn to winter during its 684 Earth day orbit around the Sun. Seasons on Mars are marked by the planet’s heliocentric longitude coordinates using the position of Mars along its orbit around the Sun. Each seasonal start/ending point is 90 degrees apart, but because of its elliptical-shaped orbit each Martian season is of varying lengths.

   I’m not exactly sure why this particular date is used but by international agreement astronomers have selected 11 April, 1955 as 0 degrees for year 1 of this Martian calendar. What this means is that on Monday November 28th, Earth time, it is the start of winter for year 33 using the aforementioned calendar system.

Year 33
0 degrees — Spring Equinox — June 18 2015
90 degrees — Summer solstice — January 03 2016
180 degrees — Fall Equinox — July 04 2016
270 degrees — Winter Solstice — November 28 2016
Year 34
0 degrees — Spring Equinox — May 05 2017
90 degrees — Summer solstice — November 20 2017
180 degrees — Fall Equinox — May 20 2018
270 degrees — Winter Solstice — October 16 2018

mars-capricornus-ani
   On the evening of Monday November 28th the planet Mars will be over the southwestern horizon at sunset and Mars will set a couple of hours later. Mars is within the constellation of Capricornus the Sea Goat.

   Learn a little (or a lot) more about the exploration of Mars at the NASA Journey to Mars web site.

Here is approximately 3 minutes worth of Mars from the Orbit performance.

   

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.

Mars at Solar Conjunction

mars-solar-conjunction-above   Sunday June 14th the planet Mars will be at solar conjunction, on the opposite side of the Sun from the Earth. Mars will reappear on the west side of the Sun as a morning planet next month and gradually will become more visible in the morning skies.
    So while Mars is out of sight for observers it is also out of ‘radio sight’ for all of the spacecraft at Mars – either on the surface or in orbit. For about a two week period between June 7th to 21st mission controllers will stop sending messages to the spacecraft at Mars, however the orbiters will continue their science observations and collecting data. The rovers on Mars on the other hand will not rove until after the radio silence period.

   
   
   
   

Caution: Objects viewed with an optical aid are further than they appear.
Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

Mars Ends Retrograde Motion

Click on graphic to see it full size.

Click on graphic to see it full size.

   Since the first of this past March the ‘red planet’ (love saying that!!) Mars has been moving in retrograde near the star Spica in Virgo. Retrograde, or retrograde motion, is an apparent reversal of an outer planet or dwarf planet’s regular orbital motion eastward around the Sun – as viewed from Earth. On Wednesday 21 May Mars ends its retrograde motion and resumes its regular or direct motion (eastward). Mars is also recently past opposition in April and so it is still near its maximum apparent magnitude (brightness) of -0.75. Nearby, for comparison, is the 3rd magnitude star Porrima.
Read more about the retrograde motion of Mars in a previous blog.

   
   
   
Caution: Objects viewed with an optical aid are further than they appear.
   Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

Mars at Opposition

mars-opposition-2014-ani   Tuesday 8 April the planet Mars reaches a point in its orbit around the Sun called opposition. This is an arrangement of Mars, Earth, and the Sun that places the three in a pattern with the Earth in between Mars and the Sun. Think full Moon and that is a good mental picture of Mars, or any of the outer planets, at opposition.

Click on graphic to see it full size.

Click on graphic to see it full size.

   At opposition, like with a full Moon, Mars will rise at approximately local sunset time and Mars will set at local sunrise time – visible above the horizon all night.
Finding Mars is fairly easy especially if you follow the ‘old’ mnemonic “Follow the arc to Arcturus, then speed to Spica.”

   This is a short 3-minute video I made as part of a live musical performance called “Orbit” that was performed at the Gottleib Planetarium in Kansas City Missouri in May 2011. This is a piece from the much longer tour of the solar system performance and video and shows a fly-by of Mars.

   
   
   
Caution: Objects viewed with an optical aid are further than they appear.
   Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

It’s Summer – On Mars

A Martian Year

A Martian Year – at One Earth Month Intervals

   Sunday January 3rd is the summer solstice on the planet Mars as the planet transitions from spring to summer during its 684 Earth day orbit around the Sun. Seasons on Mars are marked by the planet’s heliocentric longitude coordinates using the position of Mars along its orbit around the Sun. Each seasonal start/ending point is 90 degrees apart, but because of its elliptical-shaped orbit each Martian season is of varying lengths. At the Martian summer solstice Mars is at 90 degrees longitude.
Click on graphic to see it full size.

Click on graphic to see it full size.

   I’m not exactly sure why this particular date is used but by international agreement astronomers have selected 11 April, 1955 as 0 degrees for year 1 of this Martian calendar. What this means is that on Sunday January 3rd, Earth time, it is the start of summer for year 33 using the aforementioned calendar system.

Year 33
0 degrees — Spring Equinox — June 18 2015
90 degrees — Summer solstice — January 03 2016
180 degrees — Fall Equinox — July 04 2016
270 degrees — Winter Solstice — November 28 2016
Year 34
0 degrees — Spring Equinox — May 05 2017
90 degrees — Summer solstice — November 20 2017
180 degrees — Fall Equinox — May 20 2018
270 degrees — Winter Solstice — October 16 2018

Learn a little (or a lot) more about Mars at the NASA/JPL Mars Curiosity mission web site.

Here is approximately 3 minutes worth of Mars from the Orbit performance.

   
   
   
Caution: Objects viewed with an optical aid are further than they appear.
   Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.