A celestial phenomenon is forming in the Northern Hemisphere on Friday, as seven planets are expected to appear lined up in the night sky. Most are expected to be visible to the naked eye, though not all seven.
The alignment is known as a planet parade — a planetary lineup in space from Earth’s perspective. The alignment takes place over time as each planet in the solar system orbits the sun at its own speed and distance, continually changing their relative positions. All the planets orbit roughly along the same plane, known as an ecliptic plane, or arc across the sky if you are viewing it edge-on, according to NASA.
NASA recommends observing the planet parade shortly after sunset. A telescope and knowledge of a planet’s location among the are ideal to enjoying the celestial lineup.
The alignment, which may be spotted about 10 degrees above the horizon, will be visible for a while just after sunset Friday.
Sky watchers may have a difficult time spotting the entire parade — all seven other planets in our solar system besides our own — without optical aid, said Ed Krupp, director of Griffith Observatory.
The planets “are always more or less on the same path, and occasionally a few more of them are visible in the night sky,” Krupp said. “But the general message is that, ‘I will go outside and see these planets strung like pearls across the sky.’ That’s just not the case.”
Krupp noted that some of the planets require a telescope, as they are below the detectability of the human eye. And he said people should not expect the celestial show to dominate their view, especially due to the air conditions and light pollution in Los Angeles.
Some planets, including Mars, Jupiter and Venus, will appear brighter, said San Diego Community College astronomy professor Lisa Will. And though the planets may appear close to one another, they are hundreds of millions of miles apart, as NASA’s Jet Propulsion Laboratory noted.
Due to Earth’s atmosphere, celestial objects appear dimmer as they rise and set, making it difficult to see even brighter planets until they move higher above the horizon. Also, buildings and trees may obstruct the view near the horizon.
A dark, dim clear sky is the ideal setting, often in remote deserts and other areas far from city lights.
About five planets may be visible without a telescope: Mercury, Venus, Mars, Jupiter and Saturn, according to NASA. But, Krupp noted, Mercury — because it is small and orbits closest to the sun — is the hardest to see with the unaided eye, especially if the viewer does not know their way around the night sky.
“If you wanted to see Mercury, you might get lucky around the evening, shortly after the sunset, in the twilight, but only if you knew where to look,” Krupp said. “Venus, Mars, Jupiter and Saturn are all up in the sky between the western horizon and a bit overhead to the east.”
Uranus is on the threshold of human vision, Will said. Uranus and Neptune are hard to spot without a telescope, as both planets are blue and orbit in the dim outskirts of the solar system. Krupp said that even an experienced amateur astronomer with a telescope will have a hard time detecting Uranus and Neptune.
“Sometimes all people need is some guidance, and here in the observatory we have instructors and put out telescopes every night free to the public,” Krupp said. “But I worry people will be disappointed. You want people to have the direct experience of those photons from those objects going into their eyes and knowing what they’re looking at.”
The next planetary parade will be visible in late August — when four planets are expected to be viewable at once before sunrise. The next two parades after that will occur in October 2028 and February 2034.
