Earth’s small brother planet crosses the celestial equator on January 29, at 12 by Universal Time.
The red dot of Mars serves today as an almost exact marker of the point where the ecliptic and the celestial equator intersect. This – the vernal equinox point, anciently called the First Point of Aries but now in Pisces – is the point the Sun will reach at the March 20 equinox. We use it as the “origin” or zero point for our system of mapping the sky: both longitude, parallel to the ecliptic, and right ascension, parallel to the celestial equator, are measured eastward from it.
This is how the inner planets are now arranged, so that we see Mars and Venus east of the Sun.
Spatial view, from 15° above the ecliptic plane, of the planets’ paths in January, with sightlines from Earth. The dashed line and ram’s-horns symbol mark the vernal equinox direction, which at this moment is parallel to the Earth-Mars direction.
Mars will be in the northern celestial hemisphere for the next 270 days, traveling its arc through the constellations of the northern half of the zodiac: Pisces, Aries, Taurus (at the farther end of which it will be highest north, on June 6), Gemini, Cancer, Leo, Virgo, where it will descend through the equator on Oct. 26.