2016 Martian Summer Solstice

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.

   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 the exploration of Mars at the NASA Journey to Mars 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.

2015 June Solstice

21june-ecliptic   Northern hemisphere spring comes to an end and its summer begins on Sunday June st at 16:38 UT (11:38 am CDT) when the Sun ‘reaches’ the celestial coordinates of 23.5o north declination and 6 hours right ascension. With respect to the Earth’s surface the Sun is described as over the Tropic of Cancer, 23.5o, north latitude of the Earth’s equator. At this same time the Sun is still within the boundaries of the constellation Taurus the Bull – but just barely. Interestingly about 12 hours later, June 22nd at 2 UT (June 21st – 9 pm CDT) the Sun ‘will move’ into the region of Gemini as it crosses the boundary between Gemini and Taurus.
   According to the pseudoscience of astrology the Sun, at this date, would be entering the astrological sign of Cancer the Crab.
Just had to include this!!   We know that it is the Earth’s orbital motion around the Sun that causes the sun’s apparent eastward motion among the stars in the background. This is how the Sun ‘reaches’ a celestial coordinate, how it ‘crosses’ the boundaries between constellations, or how it is ‘in’ a constellation.
   With respect to the southern hemisphere this is the end of their summer and start of their fall season. So thinking globally my preference has been to use the name of the month to designate the season change. Hence the use of the term June Solstice rather than summer solstice.

   
   
   
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 Spring on Mars

A Martian Year

A Martian Year – at One Earth Month Intervals

   Thursday June 18th at 13 UT (8 am CDT) is the spring equinox on the planet Mars as the planet transitions from 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. At the Martian spring equinox Mars is at 0o longitude. Each seasonal start/ending point is 90 degrees apart, but because of its 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.
   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 Thursday June 18th at 13 UT (8 am CDT) Earth time, is the start of spring for year 33 using the Earth-designed Martian calendar system.

   Mars is currently at solar conjunction, on the opposite side of the Sun, and will not be visible until later next month, July.

Year 32
0 degrees — Spring Equinox — Jul 31 2013
90 degrees — Summer solstice — Feb 14 2014
180 degrees — Fall Equinox — Aug 17 2014
270 degrees — Winter Solstice — Jan 11 2015
Year 33
0 degrees — Spring Equinox — Jun 18 2015
90 degrees — Summer solstice — Jan 03 2016
180 degrees — Fall Equinox — Jul 04 2016
270 degrees — Winter Solstice — Nov 28 2016
Year 34
0 degrees — Spring Equinox — May 05 2017
90 degrees — Summer solstice — Nov 20 2017
180 degrees — Fall Equinox — May 22 2018
270 degrees — Winter Solstice — Oct 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.

June Solstice

Sun's Apparent Motion Along the Ecliptic

Sun’s Apparent Motion Along the Ecliptic – from Taurus to Gemini

   Northern hemisphere spring comes to an end and its summer begins at 5:51 am CDT (10:51 UT) on Saturday 21 June as the Sun ‘reaches’ the celestial coordinates of 23.5o north declination and 6 hours right ascension. With respect to the Earth’s surface the Sun is described as over the Tropic of Cancer, 23.5o, north latitude of the Earth’s equator. At this same time the Sun is still within the boundaries of the constellation Taurus the Bull – but just barely. Interestingly about 9 hours later, (3 pm CDT – 20 UT), the Sun ‘will move’ into the region of Gemini as it crosses the boundary between Gemini and Taurus.
   We know that it is the Earth’s orbital motion around the Sun that causes the sun’s apparent eastward motion amongst the stars in the background. This is how the Sun ‘reaches’ a celestial coordinate, how it ‘crosses’ the boundaries between constellations, or how it is ‘in‘ a constellation.
   With respect to the southern hemisphere this is the end of their summer and start of their fall season. So thinking globally my preference has been to use the name of the month to designate the season change. Hence the use of the term June Solstice rather than summer solstice.

   Follow the seasons by observing how vegetation changes during 1 year. The video below was produced by an Earth orbiting satellite operated by the NASA/NOAA Suomi National Polar Orbiting Partnership (NPP). It is a really interesting narrated tour of the Earth from orbit over a variety of geographic features and landscapes.

Just had to include this!!

Just had to include this!!

   
   
   
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.

June Solstice

Sun's Apparent Motion Along the Ecliptic

Sun’s Apparent Motion Along the Ecliptic – from Taurus to Gemini

   Northern hemisphere spring comes to an end and its summer begins at 12:04 am CDT (05:04 UT) on 21 June as the Sun ‘reaches’ the celestial coordinates of 23.5oN and 6 hours right ascension. With respect to the Earth’s surface the Sun is described as over the Tropic of Cancer, 23.5oN of the Earth’s equator. At this same time the Sun is still within the boundaries of the constellation Taurus the Bull – but just barely. Interestingly 9 hours later, (9:00 am CDT – 14 UT), the Sun ‘will move’ into the region of Gemini as it crosses the boundary between Gemini and Taurus.
   We know that it is the Earth’s orbital motion around the Sun giving rise to the sun’s apparent eastward motion amongst the stars in the background. This is how the Sun ‘reaches’ a celestial coordinate, how it ‘crosses’ the boundaries between constellations, or how it is ‘in‘ a constellation.
   With respect to the southern hemisphere this is the end of their summer and start of their fall season so thinking globally my preference has been to use the name of the month to designate the season change. Hence the use of the term June Solstice rather than the limited to northern hemisphere term summer solstice.

   Follow the seasons by observing how vegetation changes during 1 year. The video below was produced by an Earth orbiting satellite operated by the NASA/NOAA Suomi National Polar Orbiting Partnership (NPP). It is a really interesting narrated tour of the Earth from orbit over a variety of geographic features and landscapes.

Just had to include this!!

Just had to include this!!

   
   

   Click here to go to the Qué tal in the Current Skies web site for more observing information.