Articles written by dennis mammana
Sorted by date Results 51 - 75 of 177
Journey from Andromeda
A long time ago in a galaxy far, far away, a beam of light began its journey across the cosmos. At the remarkable speed of 186,282 miles per second, this beam could orbit our planet nearly 449 times in just one minute. But it wasn'... — Updated 10/28/2022
The Moon Meets Uranus
Go ahead. Get all the jokes out. You know you want to. I've done it too, but quite honestly, they were all much funnier in seventh grade! In a few days the planet Uranus (pronounced YOU-rah-nus, by the way), will undergo what... — Updated 10/18/2022
The Moon and the Gas Giants
The most prominent "star" on the celestial stage this week will be the moon. It will reach its first quarter phase on the evening of Sunday, Oct. 2, when you will see it due south at sunset. Its 2,200-mile-diameter orb will be sunl... — Updated 10/18/2022
Searching for Neptune After Dark
Remember a few years back when Pluto was deemed to be no longer a planet? The internet erupted with protests. "Why isn't Pluto a planet?" people cried. "It was a planet when I went to school and, as far as I'm concerned, it still... — Updated 9/27/2022
Seeing a Cosmic Yardstick
One of the most common questions I hear regards how we determine distances to the stars – a question not so easily answered by waving my arms around in the dark. Many folks think that if a star appears fainter, it must be farther f... — Updated 9/19/2022
Finding the Asteroid Vesta
I remember well those wonderful days of elementary school when the very mention of the "solar system" conjured up in my mind amazing images of the sun, the planets and their attendant moons, and even mysterious comets sweeping by... — Updated 9/13/2022
Dog Days of Summer
As summers go, this one hasn't been unusually hot here in the Southern California desert, but it's not over yet! We've still got a while before the onset of autumn and, hopefully, the arrival of some cooler temperatures. In the mea... — Updated 9/7/2022
Three Decades of Stargazing!
It's hard to believe, but it will be 30 years on Aug. 19 since I published my first "Stargazers" column. Over those years, we've seen eclipses darken the land, planets converge in the sky or transit across the sun, meteor showers... — Updated 8/30/2022
Ring World: Saturn
It's often been said that beauty lies in the eye of the beholder, so if I were to ask which is the most beautiful of all the planets, I would expect a variety of answers. Some might say it's the delicate white crescent of Venus; ot... — Updated 8/23/2022
A Stellar Chinese Valentine's Day
There's a wonderful ancient Chinese story that tells of two lovers – Niulang, a poor, orphaned cowherd and Zhinu, a young, beautiful weaving maiden and the seventh daughter of the Emperor of Heaven – who once were separated and... — Updated 8/19/2022
Ophiuchus, the Serpent-Bearer
Even beginning skywatchers can go outdoors on a clear night and easily find among the stars the classic shapes of Scorpius, the scorpion, and the teapot of Sagittarius. Right now, you can see them both low in the southern sky... — Updated 8/19/2022
Desperately Seeing Pluto
"My very energetic mother just served us nine pizzas." Anyone who's ever studied the solar system in school has learned this mnemonic device in which each word begins with the same letter as the planets of our solar system in... — Updated 8/3/2022
Check Out the "Not So Super" Moon
Here we go again. Another month, and yet another "super moon"! What's so super about the "super moon"? You may have already asked yourself this question after going out to see it and coming away thinking "Gee, it looks just like ev... — Updated 8/3/2022
Exploring the Celestial Scorpion
During late June evenings, we can easily see one of the great celestial symbols of summertime. Look low toward the southern sky after dark, and you'll spot the long, curving arc of Scorpius, the scorpion. You will easily notice... — Updated 8/1/2022
Summertime is on its way!
Officially, the summer solstice arrives this year on June 21 at 2:14 a.m. PDT (5:14 a.m. EDT). This time marks the exact moment when the sun reaches its farthest northward point over the Earth and signals the onset of summertime... — Updated 7/5/2022
Seeing the Solar System
Many celestial phenomena excite stargazers, but few are as cool as the one you can see during the next two weeks. Your only challenge will be forcing yourself to head outdoors before sunrise! If you do, and if you have a very low... — Updated 6/27/2022
The Twilight Zone
If you find yourself occasionally checking around for times of sunset, it might never have occurred to you to ask the question: "Just what is sunset, anyway?" Seems like a ridiculous question; everyone knows what sunset is, right?... — Updated 6/21/2022
Seeing the 'Unseeable'
On a recent visit to my orthopedic surgeon's office, I was struck by her remarkable ability to point out even the smallest anomalies on my knee X-rays and MRIs. "How in the world did she ever spot those?" I remember thinking. The... — Updated 6/2/2022
Make Friends with Vega
Of all the books I've read during my nearly six decades of stargazing – and there have been a lot – my favorite isn't a technical tome like you might imagine. It's actually the inspirational and romantic autobiography of the lat... — Updated 5/25/2022
A Cosmic Coverup!
I just love eclipses. Not only are they fun to watch, but an eclipse is one of the few cosmic phenomena where we can see the movement of our heavens. If you're as intrigued by these celestial events as I am, then you must plan to... — Updated 5/19/2022
Seeing Red in the Night Sky
Beginning stargazers are often disappointed when they cannot see the glorious colors that appear in celestial photographs taken by massive telescopes. Experienced sky watchers know that this is because the human eye's color... — Updated 5/19/2022
A Planetary String of Pearls
A beautiful string of planetary pearls shines at dawn right now, but one of the coolest sights of the early morning sky is completely invisible. Well, sort of. Stargazers who know something about astronomy can find it every night... — Updated 5/3/2022
Old Moon in the New Moon's Arms
It's amazing how the sky can be such a great memory trigger. I remember as a child racing home from school each day to watch "Superman" on television as the comforting aroma of my Mom's cooking would waft through the house. It was... — Updated 4/19/2022
Finding the Horse and Rider
We terrestrial stargazers have it easy. We orbit a single star, and we look out at the starry heavens and believe that all stars are like the sun. In some ways that's true. All are globes of mostly hydrogen that shine by a process... — Updated 4/15/2022
Finding the 'Dinky Dipper'
Pay attention to your everyday world and you'll soon realize that we're surrounded by astronomical words. The days of the week are named after the five visible planets, the sun and the moon. Go to a theater and you may see a film b... — Updated 4/4/2022