Star Calendar Planets:
Moon follows a sinus path tipped 5 degrees to the ecliptic, which is itself tipped 23 ½ degrees to the celestial equator. The phase of these two tipping curves slowly changes, a cycle of phase-shift taking 18.6 years. When the Moon and Sun’s (vernal) ascending nodes coincide (additive phase relationship) the Moon soars above, and plunges below, the equator with a declination range of 57 degrees – as in 2005-6. This year, some 9 years later, the curves instead subtract and we have a minimum range of declination for the Moon; being just 36-37 degrees (compared to the Sun’s steady 47 degrees). This is also referred to as a “minor lunar standstill”. Moon’s descending node will correspond with vernal equinox in March this year. For 2015, the very highest declination the Moon will achieve will be only 18 2/3 degree; on Jan 3rd.
Mercury sweeps up to meet Venus on the 11th and may be looked for in the early evenings of the following week with reasonable expectation if one has a good horizon in the WSW. Already by the 21st Mercury will be hard to find despite a helpful but very thin, young Moon nearby. February’s morning apparition will be poor but May’s will be the best for the year.
Venus continues her magnificent evening ascent at a stately pace. She will be an evening feature until June.
Sun is nearest earth on the 3rd and its disk is actually larger. Total solar eclipses are rarer in January; more common in July when more distant/smaller. The Sun also progresses faster against the backdrop of stars at this time of year.
Mars has a year 684 Earth-days long (or 668 Mars-days) during which it also has seasons. Martian solstice occurs on our Jan 11th, with the Martian North turned away from the Sun. Oddly the northern Martian winter is longer than the southern – as interpreted by the outbreak of reflective frost and dry ice at the respective poles. Martian seasons are more dramatically modified by their relationship to its apsides (proximity to the Sun) than Earth’s.
Jupiter is moving retrograde, approaching its maximum brightness for an opposition in Cancer early next month.
Saturn continues to dominate the SE before sunrise. The Moon will again pass very near on the 16th. Continue reading