Five planets will be in visible in a rare formation this weekend

Last time five plants could be seen lined up in order was December 2004

Over the weekend, Mercury, Venus, Mars, Jupiter and Saturn can be seen in alignment without a telescope.

Starting on Friday and carrying on through this month, the planets will be visible along the eastern horizon before sunrise, appearing in order of how far away they are from the sun. Mercury, the closest planet to the sun, will appear furthest down on the horizon and Saturn the highest.

The most opportune viewing time for people living in the Northern Hemisphere will be about a half-hour before sunrise. The planets will also be able to be seen in the Southern Hemisphere above the eastern and northeastern horizons.

In clear conditions, the planets should be viewable with the naked eye, but Mercury will be the faintest early on in June and could be difficult to see without binoculars. The planet will grow brighter later this month and appear higher in the sky, meaning that it will be easier to spot, according to Sky & Telescope, which is published by the American Astronomical Society.

The outlet noted that the last time five planets could be seen in order was in December 2004.

On 23 June, the crescent moon will appear between Venus and Mars. After the end of this month, Saturn, Mars, Jupiter and Venus will start to spread out “so much so that Venus and Saturn will make their exits as morning objects for most observers by September”, NASA said on its website.

A NASA image shows the expected view of the sky on 23 June (NASA)

The agency added that June is also “an excellent time to observe one of the best-known globular star clusters – M13, also known as the Hercules Cluster. Globular clusters are spherical collections of stars, tightly packed together in their centers. M13 itself contains several hundred thousand stars”.

The stars in M13 are thought to be 12 billion years old “approaching the age of the universe itself”, the agency added.

“Our home galaxy, the Milky Way, is known to have about 150 globular clusters. They orbit outside the galaxy’s disk, traveling tens of thousands of light-years above and below its spiral arms and most of its stars,” NASA said.