How to see five planets at the same time

These two ice giants that revolve around Saturn are modern planets. They were not known in antiquity because their discovery required the help of a telescope and the understanding of gravity to understand how the solar system works.

But although they are not visible to the naked eye, Uranus is low in the east at sunset and Neptune is higher, about halfway to Mars.

Experienced observers, observing the sky from a dark country site, could see Uranus at the naked eye knowing exactly where to look. Through binoculars, Uranus appears as a weak star, but a good telescope will show its slightly bluish disc.

It is best to wait until later in the evening, when Uranus will climb higher, to try to observe it. But this is the ideal moment, because the planet is getting closer to the opposition on October 24, when it will be at its best.

Neptune is about the same size as Uranus but is much farther away, which makes it harder to see. Even with a modest telescope, it appears as a bluish star, while the proper viewing conditions and a high quality telescope are needed to reveal the Neptune disk.

Finally, and not to be outdone, even the Pluto dwarf planet joins the crowd. It is far too small and distant to be seen, but is currently halfway between Saturn and Mars.

Even with a high quality telescope, Pluto never appears as a star-like object, and most people will find it hard to find it in its current position among all the stars close to the brilliant Milky Way.

If you're up for the challenge, a free astronomy program like Stellarium is great for helping you locate planets. But it is equally gratifying to take advantage of the five luminous planets, observed since ancient times, which meet briefly in the western sky.

Tanya Hill is an honorary member of the University of Melbourne and Senior Curator (Astronomy) at Museums Victoria.

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