Jupiter and Saturn last aligned on May 21, 2000. Jupiter and Saturn are slowly creeping into alignment again because of the relative speeds of their orbits. The conjunction of Jupiter and Saturn will occur on December 21, 2020. At that time, these planets will line up quite close to the sun, as seen from the Earth. They will be low in the sunset sky.
According to Kepler’s Laws of Planetary Motion, planets move faster in their orbits if they are closer to the sun. Conversely, the further a planet is away from the sun, the slower it moves. Jupiter is quite far from the sun at five astronomical units, and a “year” on Jupiter is as long as 12 Earth years. So Jupiter is seen passing through the zodiac at the leisurely rate of one constellation to the east per year. This is why Jupiter was passing through Libra last year and is now in Scorpius in 2019.
This December, our planetary pair will be hanging low in the evening sky, soon to disappear into the sunset. On the evening of December 16, 2020, the waxing crescent moon will align with these planets in the twilight sky on the threshold of winter. Jupiter meets Saturn for the first time in 20 years on December 21, 2020.
There are new constellations found in the universe but the discovery of the 13th star sign can be disregarded for modern horoscope readings as Ophiuchus is a constellation, not a zodiac and cannot be used in star signs.
The 12 zodiac signs are those twelves constellations that the Earth passes along it’s orbit around the sun. Sun signs are often what we call star signs. There are also moon signs and rising signs that correlate with each other (more coming on that soon).