• Somewhere around 45 to 90 minutes after sunset, see if you can use the waxing crescent moon to find the planet Mercury and the two Gemini stars Castor and Pollux. They'll be low in the sky, not much above the horizon, so you'll need an unobstructed view in the direction of sunset to see them. Seek for this celestial foursome as dusk is giving way to darkness, for the moon, Mercury and these stars will follow the sun beneath the horizon by nightfall. Binoculars may be helpful.
• Setting times for the sun and Mercury
• Mercury, the innermost planet of the solar system, circles the sun in only 88 Earth-days. Even though Mercury has

the shortest year of any solar system planet, it also sports the longest day. One day on Mercury is equal to 176 Earth-days. On Mercury, one day is twice as long as one year.
• June 2012 guide to the five visible planets
• If you lived on Mercury, you'd see the sunrise in the east, then the sunset in the west some 88 Earth-days later. However, when Mercury reaches perihelion - its closest point to the sun for the year - you'd see the sun stop, then go eastward for a while before resuming its normal westward motion. If you were on the right place on Mercury, you could actually watch the sun rise, go back under the eastern horizon, and then rise again.
• Like on Earth, the westward movement of the sun during the day is due to the

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