STARGAZERS will be in for a treat this week when the planets align.

The planetary alignment of Mercury, Mars, Jupiter and Venus, which happens once every two to three years, started at the end of last month.

But the alignment, or conjunction, will be most prominent in the pre-dawn hours of May 12.

Port Macquarie astronomer David Reneke said while planets would never technically fully align, they would all be in the eastern sky within six degrees of each other.

“The last one we had was around 2009 and in 2008 there was a conjunction in the shape of a smiley face,” he said.

“All the planets travel around the sun in different orbits and occasionally they all catch up with each other every few years.

“It is going to be nice because you can look in one direction up at the sky and will have four planets to look at. And 4am is not an ungodly hour to see it.”

The forecast for Thursday, May 12 is sunny from Tweed Heads to Grafton but people up to watch the galactic show should get cosy as temperatures will drop to eight degrees at night.