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Articles by J. Alex Knoll

Circling earth at more than 17,000 miles an hour, the International Space Station is a fleeting target

  Sharp eyes and a clear view of the west horizon will reveal an ever-so-thin crescent moon emerging from the sun’s glare Friday just after sunset at 8:11. But you’ll also need good timing, as this nascent moon, just a day from new, dips beneath the horizon within 30 minutes of the sun.  Sunset the next night is a minute later, and it reveals the moon 15 degrees higher. Above and to the left shines dazzling Venus. Sunday, the moon and Venus are still only six degrees apart...

Look low in the west after sunset for your own UFO

  The great astronomer-novelist Arthur C. Clark once said, “If you’ve never seen a UFO, you’re not very observant. And if you’ve seen as many as I have, you won’t believe in them.” A few hours after sunset, you may very well spot your own unidentified flying object hovering above the horizon or perhaps zipping through a stand of trees.  While it may be breathtaking, fans of the X Files and Area 51 conspiracy theorists will likely be disappointed....

All those phases are just figments of our own perception

  May’s full moon rises at 8:22 Thursday in the southeast just as the sun sets in the northwest. It travels a low, shallow arc through southern skies, finally setting in the southwest just as the sun crests the northeast horizon at 5:44. With spring fully abloom, this is known as the Flower Moon, the Corn Planting Moon and the Milk Moon. Over the ages we have given the moon its many folksy names to describe the seasons here on Earth. Of course, it’s always the same old moon....

While binoculars help reveal distant stars and planets, our own galaxy is disappearing before our very eyes

  As the sun sets around 8:30 this week, Venus appears in the west, the brightest object visible. Note the difference between Venus and the two first-magnitude stars Castor and Pollux a few degrees above and to the left. Venus sets in the northwest around 11pm, and pretty much sticks to this schedule throughout summer. Sunset also reveals our other neighbor, Mars, high in the southwest. Mars has been inching to the east, toward the blue star Regulus of Leo the lion. The evening of Sunday...

The heavenly bull’s glare

As darkness settles, the bright glow of Jupiter pierces the east-southeast horizon, by far the brightest light in the sky, as the moon spends this week waning through pre-dawn skies. The gaseous giant is high in the south at midnight, and as dawn nears, it sets beneath the western horizon. Around 10pm, the star Aldebaran rises in the east. The red glaring eye of Taurus the bull is one of the oldest recognized stars within one of the oldest recognized constellations. Among the paintings found on...

A lot of factors explain this puzzle

  Summer solstice is still more than a week away, but the sun rises its earliest of the year just before 5:40 Monday the 14th. While solstice is the longest day of the year, it marks neither the earliest sunrise nor the latest sunset, which falls a week after solstice. This is due to several interacting factors cumulatively called the Equation of Time. Earth spins on its 231x2-degree tilt of rotational axis, which causes the changing seasons. It also affects the time of day that the sun...

Still plenty to see in nine hours

  The waxing moon reaches first-quarter phase Friday, appearing high in the southwest with sunset at 8:24. Each night after, the moon appears 15 degrees farther to the east and sets roughly 30 minutes later.  Thursday the moon shines less than 10 degrees to the right of Mars, well within the space of your fist held at arm’s length. A little beyond Mars shines Regulus, the heart of Leo the lion. While Mars is only a little brighter than its apparent stellar neighbor, the planet...

The sun’s lost ground is the skywatcher’s gain

  As if to hammer another nail into summer’s coffin, the sun this week sets before 7:00. The darkening sky reveals Venus tight above the southwest horizon, and while the evening star is brilliant at magnitude –4, it, too, is fleeting and sets shortly after the sun. As the sun and Venus set in the west, Jupiter rises in the east. Last week this gaseous giant reached opposition — its point opposite the sun as seen from our earthbound vantage — and so rises with sunset...

The sun’s lost ground is the skywatcher’s gain

  As if to hammer another nail into summer’s coffin, the sun this week sets before 7:00. The darkening sky reveals Venus tight above the southwest horizon, and while the evening star is brilliant at magnitude –4, it, too, is fleeting and sets shortly after the sun. As the sun and Venus set in the west, Jupiter rises in the east. Last week this gaseous giant reached opposition — its point opposite the sun as seen from our earthbound vantage — and so rises with sunset...

Looking at a star map, the world really is turned upside-down

A reader asked what she was seeing from her northeast-facing window. “Would I see evening or morning stars in this direction?” And would the same be true for planets? “I did look at your column and thought I understood the paragraph about Venus, but now I'm not so sure. Help! Thanks a bunch.” Only after reading and re-reading did I realize her problem: I was flat-out wrong, falling victim to my own sky map, inverting east and west, thus greatly confusing this reader...