Last modified: Thursday, June 1, 2006
Mars and Saturn meet near the Beehive
BLOOMINGTON, Ind. -- If you've never seen Mercury, the smallest planet visible without optical aid, June will offer a fine opportunity. Mercury will climb high above the west-northwestern horizon after sunset, forming a triangle with the bright stars Castor and Pollux of the constellation Gemini the Twins. Mercury will be noticeably brighter than either of the stars.
Unlike the outer planets, which remain easily visible for months, Mercury will take only three or four weeks for its entire appearance, from when it first becomes visible above the horizon to when it drops back into the solar glare. To find it, first find a place where you have a clear view of the west-northwestern horizon and mark the spot on the horizon where the sun sets. Come back about 45 minutes later with binoculars and look just above the spot that you marked. It should be easy to find the bright dot of light even in the glow of twilight. Each day Mercury will be higher above the horizon, until you can see it easily even without binoculars in the darkening sky. It will reach its peak around midmonth.
To the upper left (west) of Mercury, Mars and Saturn will have a very close approach on the evening of June 17, after gradually drawing closer during the first part of the month. This will be the closest that Mars and Saturn have been in the evening sky since 1978. Pale orange Mars will rise toward yellow Saturn and then continue upward after they appear to pass each other. Binoculars will show Mars right in the middle of the Beehive star cluster on June 15.
Jupiter will dominate the evening sky high in the south after sunset in early June, gradually moving into the southwest as the month goes by. The huge planet will outshine all the stars, and it will be easy to spot until it sets well after midnight. Jupiter and its moons will be a fine target for telescopes all month.
Venus will be a dazzling white "morning star" during June, rising in the east-northeast around the start of morning twilight.
Viewing information and graphics for the planets are available at http://www.space.com/spacewatch.
The brightest star high in the east-northeast after dark in June will be Vega. The brightest star to its lower left (north), by two or three fist-widths at arm's length, will be Deneb. About the same distance to Vega's lower right (south) will be Altair rising in the east. These three stars form the huge Summer Triangle, which will cross the sky high overhead during the night. Details about the Summer Triangle and what it encloses can be found at http://www.idialstars.com/stri.htm.
The sun will reach the June solstice on June 21 at 8:26 a.m. EDT (12:26 Universal Time), marking the start of summer in the Northern Hemisphere and winter in the Southern Hemisphere. For the next six months in the Northern Hemisphere the days will be getting shorter.
Officially the first day of summer, the June solstice is also referred to as Midsummer because it is roughly the middle of the growing season throughout much of Europe. Most societies in the Northern Hemisphere, ancient and modern, have celebrated a festival on or close to the June solstice. The themes common to all of these festivals are fertility and agriculture.
"Solstice" is derived from two Latin words: sol meaning sun, and sistere, to cause to stand still. This is because the sun climbs to a higher point in the southern sky each day until the summer solstice. On the day of the solstice it appears to arrive at about the same maximum height above the horizon as the day before, and in the days afterward its maximum point is lower, dropping back toward its lowest point at the winter solstice. In this sense, the sun "stands still" at the peak of its journey across the summer sky before it starts downward again toward the southern horizon.
The moon will be at first quarter on June 3, full on June 11, at third quarter on June 18 and new on June 25.