In early evening twilight, near the top of an azure sky, a singular golden point of light appears to the inquisitive sky gazer. It is Arcturus (-0.07magnitude), the brightest star in the summer sky, high in the southeast at about 9:10pm.
Gazing in a northerly direction, one other ray of starlight penetrates Earth’s dimming blue atmosphere: it is the second brightest star, bluish-white Vega (0.00m), not quite as high, in the east-northeast. Mark the astronomical beginning of summer in the night sky by finding the Summer Triangle of stars (see illustration), visible in the east to northeast at nightfall and traveling the sky all night. Altair (0.75m), the last vertex of the Triangle to come into view, clears the eastern horizon by 9pm this evening.
Mercury, Venus, Mars, Jupiter, Saturn… that’s their order outward from the sun, and it’s the order you’ll see June’s planetary lineup, stretched across our morning sky. And don’t forget the sixth planet, the one you are standing on: Earth. You’ll be able to see all five planets with the unaided eye until Mercury slips away in the morning twilight in early July.
Summer Solstice, June 21, marks the Sun’s northernmost and highest point in our sky. The latest sunsets of the year in our locale, within about a minute of 8:31pm, take place from June 18 through July 6. Civil twilight begins half an hour after sunset; astronomical twilight, genuine darkness, roughly two hours after sunset.
Earliest sunrises of the year, within a minute of 5:25am, began on June 11 and continue through June 23. The longest days of the year, which we are basking in right now, culminate next week when, from the 20th through the 23rd, there are 15 hours and 6 minutes from sunrise to sunset. The remaining 8 hours and 54 minutes includes morning and evening twilight.
In closing, for early morning (4:15am) astronomy enthusiasts, I am including an illustration of the current five planet extravaganza, offered courtesy of EarthSky.org.
Judy Isacoff, naturesturn.org
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