Topline
A very rare planetary alignment on Tuesday, Jan. 21 and Saturday, Jan. 25 is being promoted online. It’s not specific to those dates, but six planets are now in the night sky, four of them visible to the naked eye.
Key Facts
Four planets are visible in the night sky immediately after sunset, with Venus and Saturn in the southwest, Jupiter high in the southeast and Mars in the east.
The best time to look is around 45 minutes after sunset when you are until around three hours later when Venus and Saturn will set in the west.
It’s not correct to call the gathering of planets an alignment. “Planets always appear along a line in the sky, so the ‘alignment’ isn’t special,” wrote Preston Dyches, Public engagement specialist at NASA, in a blog post. “These multi-planet viewing opportunities aren’t super rare, but they don’t happen every year, so it’s worth checking it out.”
There are two other planets in the night sky, though neither is bright enough to be without a telescope. Neptune is just above Venus and Saturn, while Uranus is just above Jupiter.
Mercury, the closest planet to the sun, is the only one missing from the night sky. It’s currently in the morning sky, though lost in the sun’s glare. Earlier this month, the BepiColumbo spacecraft took close-up images of its craters.
Key Background
If a planet is visible from the night side of Earth, it’s always seen along an imaginary path through the sky called the ecliptic. This is the plane of the solar system. The ecliptic can easily understood if you picture a flat, round disk with the sun at the center, according to Sky & Telescope. All the planets, from Mercury out through Neptune, circle it in roughly the same plane. All of the planets, as well as the sun and moon, appear to travel along this path in the sky.
Mars At Brightest Since 2022
Currently rising in the east as the sun sets in the west is Mars, which on Jan. 12 reached “opposition” when Earth is precisely positioned between it and the sun. Now closer to Earth than at any time since late 2022 and until early 2027, the red planet—visible below Jupiter—looks a golden-reddish color to the naked eye.
On Jan. 13, the first full moon of the year, the “Wolf Moon,” dramatically occulted Mars, moving across to hide the red planet for around an hour as seen from North America. Mars was about 266 times farther away than the moon.
Tangent
The “planet parade” will continue through February, with a crescent moon joining on Friday, Jan. 31, when it will shine one degree from Saturn. The following evening, on Saturday, Feb. 1, a crescent moon will shine two degrees from bright Venus.
These spectacular sights will occur just days after the new moon on Wednesday, Jan. 29, which will signal the beginning of the Chinese Lunar New Year, the “Year of the Snake.” Its timings are based on the traditional Chinese lunisolar calendar, which uses the moon’s phases and the Earth’s orbit around the sun, and will end with the rise of the full “Snow Moon” on Wednesday, Feb. 12.