Get the binoculars and set the alarm.

For the first time in 18 years, five planets – Mercury, Venus, Mars, Jupiter and Saturn – will align sequentially and be visible at dawn throughout this month.

Those watching from the continental United States should be able to watch, as long as they're up early enough, Diana Hannikainen, Sky & Telescope's observing editor, told NPR.

Five-planet alignments are not "extremely rare," Hannikainen said. These planets last aligned in sequential order in 2004, and will happen again in 2040.

"But it's rare enough that if we get a chance to go out in the morning and check it out, it's worth it," Hannikainen said.

As June goes on, Mercury will become easier to see, she said. On June 24, the sighting is expected to be particularly special. On that day, viewers should also be able to see the waning crescent moon between Venus and Mars.

If you want to take a look, make sure you're at your viewing spot about 30 minutes before sunrise, Hannikainen says. For most, an ideal location should have a clear view of the horizon to the east. And binoculars are critical, she adds.

"Don't be disappointed if you don't catch Mercury early," she says. “Some people may be able to catch the five planets at the beginning of the month, but don't be too disappointed. The four planets are already a beautiful, beautiful sight.”