Thursday, June 23, 2005

When Worlds Collide

When Worlds Collide
by Dave Adalian

The cusp of June into July is going to be a planet-hunter’s delight this year.

Eighty-eight-thousand-mile-wide Jupiter continues to reign over the southern sky, shining high after sunset. Ruddy Mars, as it moves toward another close pass by Earth in mid-November, is coming up in the east for night owls at around 1:30 a.m., just as Jupiter is retiring on the opposite horizon.

The three outer planets--Uranus, Neptune and Pluto--are all available to those with telescopes during various times through the shortened dark hours of early summer. From an unpolluted sky, those who know exactly where to look, perhaps by using an online guide such as, can see blue-green Uranus with the naked eye.

The real show, however, is in the west just after the Sun reaches the horizon.

Those who followed the progress of Saturn this year as it hovered in the constellation Gemini know it is coming to the end of its 2005 appearance. As June closes, Saturn is only visible for a short time before it follows the Sun and slips below the western horizon.

Already Saturn is almost lost in the afterglow of twilight and hard to see until at least 30 minutes after the Sun is gone. Look tonight around 9 o’clock to see that Saturn has a bright companion, Venus, sitting very close by and outshining it.

In fact, brilliant Venus sits at the center of a trio of planets, with Saturn to her left and speedy Mercury on the right. Together the three span only three degrees, just six full-Moon widths.

Friday the trio is even tighter, sharing just two degrees of sky, and the group will be its tightest on Saturday when Saturn, Venus and Mercury are just one and a half degrees apart with the ringed planet below the two innermost planets of our star system.

While they sit close compare the pink of Mercury, blue-white Venus and yellow Saturn. Notice too how the trio sits undisturbed in the sky while around them stars shimmer in the gloaming.

Keen-eyed observers noticed Mercury rising to meet Venus while the planetary trio gathered. Mercury moves closer still the next two nights as Saturn retreats until on Monday the two are less than one tenth of a degree apart, so close they may appear to the eye as a single point of light. The merger is a once-in-a-lifetime event, not happening again until 2070.


This column appeared originally in the Visalia (Calif.) Times-Delta on June 23, 2005.