All five of the "naked-eye" planets will be visible in a rare alignment for the remainder of June. But when is the best time to observe this event?

Throughout this period, the five planets—Mercury, Venus, Mars, Jupiter and Saturn—will all be visible in the sky in the same sequential order as they orbit the sun.

This particular alignment, which is the result of how the planets are positioned in their physical orbits around the sun, hasn't occurred for 18 years.

"Seeing all the five naked eye planets in such a parade, moreover in the same order of their increasing distance from the sun, from Mercury on the left to Saturn on the right, does not happen frequently," Gianluca Masi, an astronomer from the Virtual Telescope Project, told Newsweek. "Last time this happened was in December, 2004."

This planetary parade is only visible at certain times—namely, in the dawn sky wherever you are located.

"People will need to be up before sunrise and look toward the east-southeast," Diana Hannikainen, observing editor of Sky & Telescope magazine, told Newsweek.

"They'll need to find an unobstructed horizon, such as a lake, or a field, or a hilltop, with clear views to the horizon. They should get into place about an hour, an hour and a half before local sunrise. Any morning that's clear between now and the end of the month is worth taking a peek."

It is good to be outside a little early in order to orientate yourself and find a suitable place to observe the event.

Once you are set, you should look east around 45 minutes or so before local sunrise, where you will find Jupiter and Venus immediately—they are very bright—according to Masi.

"Then locate Mars (between Jupiter and Venus) and Saturn (on the right of Jupiter, looking South). Mercury will be the last one to show, below Venus and low above the horizon, close to the point where the sun is going to show," Masi said.

The alignment has been visible throughout the month of June, but around this part of the month is a great time to observe the parade because Mercury is particularly bright, according to Masi.

"Also, the Moon is moving in the same spot of the sky, adding its beauty to the scenery," he said.

The moon will appear near Venus on June 26 and Mercury on June 27, which would both be good opportunities to observe the alignment.

Observers will not need any special equipment apart from their own eyes to view the alignment, although binoculars are always helpful, especially to pick out Mercury, which can be a bit tougher to spot at times, according to Hannikainen.

Difficult to Spot Mercury

Robert Massey, the deputy executive director of the U.K. Royal Astronomical Society, told Newsweek that in general, people in the Southern Hemisphere will get the best view because Mercury will be much easier to see there.

"As far north as southern Europe and the southern United States, observers should be able to see all five planets fairly easily, but Mercury is really low and difficult when you get as far north as the U.K. and Canada," he said.

"The reason is that the tilt of the ecliptic—the imaginary plane of the solar system—has a very shallow angle up here in the June morning sky, whereas in the southern hemisphere it makes a steep angle to the horizon."

The five "naked eye" planets that are visible in June's rare alignment—Mercury, Venus, Mars, Jupiter and Saturn.iStock / Getty Images