Mercury and Venus do the tango
June 2005: Comets cruise the dead of night while the inner planets dance in twilight. Still, gas giant Jupiter remains the most prominent target this summer.
Have you ever wanted to see two planets together in a high-power field of view? Well, you get that chance June 27 around noon EDT. That's when Mercury's orbital dance brings it a mere 4' from Venus. Through a telescope, that gap covers a similar angular extent as the Moon's Mare Crisium. The pair appears less than a Moon-width apart for a few days on either side of the 27th.
The best way to find Venus during daylight is with a go-to telescope. This avoids the risk of accidentally pointing your scope at the Sun, which will cause irreversible eye damage. If you don't own a go-to scope, it's better to wait until after sunset and view the planets when they lie slightly farther apart. The tilt of Earth's axis this month brings the Northern Hemisphere its summer solstice and also causes these planets to be low in the evening sky. You may need binoculars to spy them 30 to 45 minutes after sunset.
This is the final conjunction in a series of five that began last December. The two inner planets haven't appeared this close since 1990.
If you want a last look at Saturn before it disappears behind the Sun for a couple of months, you must locate it before the sky grows completely dark. Turbulence in Earth's atmosphere will degrade the view through a telescope with each passing minute. Late in the month, Saturn joins the dancing duo of Mercury and Venus.