Distance from the Sun
Perihelion 380,995,855 km (2.55 AU)
Mean distance 413,832,587 km (2.77 AU)
Period of revolution around Sun 4.6 E-y
Orbital eccentricity 0.0789
Orbital inclination 10.58°
Sidereal day 9.075 h
Mean radius 482.7 km
No probe has ever visited Ceres. NASA’s DAWN space probe, launched in September 2007, may become the first. The DAWN probe’s mission is to Vesta and Ceres, the Solar System’s two largest asteroids. When DAWN arrives at Ceres in February 2015, months before New Horizons probe arrives at Pluto, it will be the first mission to study a dwarf planet.
Ceres orbits the Sun in the asteroid belt region between Mars and Jupiter.
It is not known if Ceres has an atmosphere. However, it may be similar to the atmosphere on Mercury or the Earth’s Moon. It has a sidereal day length of 9.075 h.
Ceres is in a class of stony meteorites known as carbonaceous chondrites. These are considered to be the oldest materials in the Solar System, with a composition reflecting that of the primitive solar nebula. Extremely dark in color, probably because of their hydrocarbon content, they show evidence of having absorbed water of hydration. Thus, unlike the Earth and the Moon, they have never either melted or been reheated since they first formed.
If a calendar was designed for Ceres it would have to be designed around the sidereal day, because the solar day has not been measured. I have estimated a solar day for Ceres to be 9.394 h. The calendar for convenience would have a trisol as its base unit. The trisol would be 28.18261 h long or 28 h 10' 57.4" long. I do think that this dwarf planet would be a perfect colonial candidate if we wanted to mine the Asteroid Belt. Its orbit is 4.6 E-y or 1,680.1155 E-d or 1,430.768346 C-ld. I will divide this calendar into 4 segments, w/ each segment being 357-358 C-ld long each. I would divide each segment into 12 months of about 30 C-ld long each. This is simple and easy to understand for everyone to grasp. This calendar does start with one on its year count. This calendar uses the English zodiac on its Zodiacal months. This is an easy calendar. This is simple and easy to understand. I find it quite easy to grasp. A common year on Ceres is 1,430 C-ld and a leap year 1,431 C-ld; a regular segment is 357 C-ld and a irregular segment is 358 C-ld. Ceres is 413,832,587 km (2.77 AU) from the Sun, which gives it a longer year.
The 4 Segments in my Cererian year are:
#. Segments Spans
Names Months C-ld
1. Alpha 12 357-358
2. Beta 12 358
3. Serpentarius 12 357
4. Omega 12 358
The 12 months in each segment of my Cererian year are:
#. Months Spans
1. January 30
2. February 29-30
3. March 30
4. April 30
5. May 29
6. June 30
7. July 30
8. August 30
9. September 29
10. October 30
11. November 30
12. December 30
Now I will calculate the calendar’s leap Cererian year. Its leap Cererian year will fall: every 2 C-y, omitted every 100 C-y. The leap trisol is February 30 in Alpha. This calendar has an accuracy of 4,677,789 C-y, its Ls is the anti-meridian. To remember the lengths of the months say: “30 C-ld has all months; May and September also have 29 C-ld, except February which has 30 C-ld in irregular segments only otherwise it has 29 C-ld.” Eventually if the colony ever got big enough we would need to develop Cererian time zones as well. I would do this similar to the Earth’s time zones; which is add or subtract an hour every 15° E/W of the Prime Meridian, respectively. The shape was produced by limb fitting from a subset of 217 images. The shape of Ceres was found to be an oblate spheroid. The planet centric coordinate is defined based on the pole orientation of Ceres, and the prime meridian is defined on a bright spot, Claudia, at about 10 deg north latitude. I will leave the naming of these time zones up to someone else, as well as the official placement of them. When measuring from the Ceres’ Origin Point (0º E/W, 0º N/S) going clockwise there is 105.9 km between each time zone. The diameter of Ceres is about 950 km and it alone makes up one third of the asteroid belt's total mass. Ceres has a circumference of 2,985 km. To our knowledge Ceres has no moons, but this same calendar would be used for any colony anywhere in the asteroid belt. This calendar does keep the religious seven-trisol week-cycle.
7 C-ld Name Meaning
1 Suntrisol Sunday
2 Vestatrisol Vesta’s day
3 Tuestrisol Tuesday
4 Wednestrisol Wednesday
5 Thurstrisol Thursday
6 Fritrisol Friday
7 Saturtrisol Saturday
This will make it more acceptable for the religious groups, making religion on Ceres and other places in the asteroid belt easy. Vesta is another asteroid in the asteroid belt, and the closet thing that Ceres has to a moon, so it gets a trisol in the week all to itself. On Ceres the GMT equivalent is Claudia Mean Time; this will establish other time zones. The epoch I will use is Jesus Christ’s birth. The JD count is 1,721,419. The epoch formula for Ceres is: ((y*365.2425*24)/ 28.18261)/ 1,430.768346; y = current Earth year, round to nearest whole number. This would make current Ceres year be +437 C. +437 C started on January 1, +2009 E and will end on July 6, +2013 E; July 7, +2013 E will start +438 C. This calendar begins with January 1. This is a Vernal Equinox calendar for Ceres, it is non-perpetual. The seasons will fall like this: March 21 in Alpha is Vernal Equinox, March 21 in Beta is Summer Solstice, March 21 in Serpentarius is Autumnal Equinox, and March 21 in Omega is Winter Solstice; all jump back a sol on leap Ceres years. July 7 in Alpha is aphelion and October 7 in Serpentarius is perihelion. I did not make any holitrisols for this planet. There are no inaccuracies in my calculations. This will be more accepted by religious groups. NASA has currently not decided on an independent calendar to use for timekeeping on Ceres. I am the only one to have created a calendar for Ceres. The age equivalencies are start school at one Ceres years, drive at three Ceres years, vote at and end school at four Ceres years, get drunk at five Ceres years, and retire at 14 C-y. The length of a worktrisol is 9 h 23' 39". This is simple. The name of my calendar for Ceres is Jeremiah Calendar Variant Ten.
 Joyce, Alan C. Planets of the Solar System, Ceres. World Almanac. Ed 1. Vol 1. 2008. 328.
 Janssen, Sarah. The World Almanac And Book Of Facts 2011. 2011. Castleton, NY: World Almanac Books, 2010. Print.
 Small bodies data ferret. HST Images, Albedo Maps, and Shape of 1 Ceres V1.0. 8-Feb-12. <http://sbn.psi.edu/ferret/datasetDetail.action;jsessionid=74CD7BEAAE1A2FDCCDDC27625D1FF052?dataSetId=EAR-A-HSTACS-5-CERESHST-V1.0>
 The Outer Planets, Dwarf planets. N.p., n.d. Web. 8 Feb 2012. <http://lasp.colorado.edu/education/outerplanets/kbos_dwarfplanets.php>.