Articles written by dennis mammana
Sorted by date Results 76 - 100 of 177
The Falling Stars of April
I had just begun one of my popular outdoor Night Sky Tours the other night when my guests erupted with gasps and cheers. While I wanted to believe that it was my captivating repartee that excited them, I knew exactly what had... — Updated 5/3/2022
Enjoying This Week's Full Moon
Last week, the delicate crescent moon appeared in the west at dusk; this week we can look forward to seeing a brilliant full moon illuminating the east around the same time. When the full moon rises around sunset on Friday and... — Updated 4/19/2022
What Time Is It?
Here we are at that magical time of year when I encounter a surprising number of people who believe that we lose an hour by resetting our clocks forward from "standard" time to "daylight saving" or "summer" time. It's a ritual... — Updated 3/22/2022
A Rivalry of Cosmic Proportions
Gazing into the dark, starry heavens of a cool springtime evening is one of the most delightful and tranquil experiences one can have. Often the most dramatic event we might experience is to watch as a meteor rips across our sky.... — Updated 3/22/2022
Finding the Celestial Lion
I've been fortunate to spend more than three decades working in some of our nation's great planetariums and, as springtime approaches each year, I always think back to elementary school and those wonderful field trips to... — Updated 3/7/2022
Big Dipper Through the Millennia
Decades of living and working on this planet have taught me many lessons, but one appears truer than most: Whatever seems temporary is permanent, and whatever seems permanent is temporary. This applies everywhere: buildings,... — Updated 3/4/2022
Measuring Heights with Shadows
Sharp-eyed observers may have noticed that, since the first day of winter more than a month ago, the sun has climbed higher in our midday sky. Of course, the sun will continue its daily climb until the first day of summer when it... — Updated 3/1/2022
Find the Celestial Beehive
Every year around this time, when it seems that wintertime will just never end, I begin looking for signs of springtime. As a child, I'd spend part of each February day on my knees in my mom's garden, brushing away the snow in... — Updated 2/25/2022
The Celestial River
You can stand outside every night of the year and you won't see stars more brilliant than those of winter. Most remarkable is that during the early evening hours right now you can find three-quarters of the 50 most brilliant stars... — Updated 2/8/2022
Sneak A Peek at the Springtime Sky
I know it's still quite cold and snowy in many locations, but every year around this time I begin to get excited about the upcoming springtime season of stargazing. During evening hours in late January and early February, we on... — Updated 2/2/2022
A Stunning Celestial Sparkler
Don't be surprised if you find yourself picking up the phone this week to report a strange "UFO" in the southeastern sky not long after dark. It will appear as a brilliant light that flickers and sparkles in a multitude of colors.... — Updated 1/27/2022
Check Out Monday's Mini-Moon!
At least once a year we hear about the supermoon – when the full moon appears largest in our sky. Why, however, do we rarely hear about the full moon appearing at its smallest? Why doesn't this make the headlines? Why don't we g... — Updated 1/24/2022
Brightest Stars of the Year
If you haven't been stargazing for a while, you might be surprised to step outdoors under a dark sky to see the stars rising in the east during late December. You may often hear astronomers refer to the winter sky as the most... — Updated 1/14/2022
An Exciting New Year of Celestial Wonder
Like many people, I enjoy the beginning of a new year. It's always brimming with hope and optimism, as well as endless lists of resolutions we swear we're going to attack, but which usually survive a few days at most. There is one... — Updated 1/13/2022
Big Moon A-Risin'
Few things in nature are more stunning to watch than an immense and orange full moon rising over the horizon. View this amazing sight just once and you'll surely ask the same question as every other moon gazer: "Why does the moon... — Updated 12/29/2021
The Winter Solstice
One of my favorite days of the year is right around the corner. Christmas? New Year’s Eve? Valentine’s Day? Nope. I’m talking about the first day of winter. Now, lest you think that this ol’ desert rat enjoys the cold, crisp air of the season – or perhaps the snow that piles up... — Updated 12/21/2021
Buying a First Telescope
During my many public stargazing programs guests frequently ask me, "What kind of telescope should I buy?" My response isn't quite what they expect. If you're considering presenting that special stargazer in your life with a... — Updated 12/21/2021
Falling Stars of December
Ask any beginning stargazer which they think is the most spectacular meteor shower of the year and I'll bet most will name the Perseid shower of mid-August. Is it really the best, or is their answer influenced by other factors? My... — Updated 12/15/2021
Shadow on the Moon!
Night owls and insomniacs will be the only ones to witness a rare cosmic alignment this week. On the night of Nov. 18 and the morning of Nov. 19, the full moon drifted slowly into the shadow of the Earth, creating a beautiful... — Updated 12/7/2021
Finding the Seventh Planet
Many years ago, I was interviewed by a couple of morning radio jokesters in San Diego. Knowing what these guys were like, I was prepared for their silliness and had planned a few good comebacks. Well, to my surprise they played it... — Updated 11/19/2021
Seeing Double in Perseus
One autumn night in 1971 while I was a junior in college, I hosted a small group in our observatory to view the wonders of the heavens. Shortly after beginning, we smelled smoke, not uncommon during chilly November nights in... — Updated 11/12/2021
Watching Earth-Orbiting Satellites
Baby boomers may recall the first days of spaceflight. It was an exciting time to be a child. From time to time, my father would step into the backyard for an evening smoke, and I would often accompany him to gaze into the starry... — Updated 10/29/2021
The Smallest Constellations (Asterisms)
Unlike people, who the U.S. Constitution declares as "being created equal," constellations are most certainly not. In fact, constellations aren't even visible. They are simply regions of the sky that were important to the... — Updated 10/19/2021
How Many Stars Are There?
How many stars are there in the universe? No one knows, of course, but Dr. Carl Sagan -- in his popular 1980s television series "Cosmos" – famously said that there are "more stars in the universe than there are grains of sand on a... — Updated 10/8/2021
A Flying Horse, Baseball and Politicians
What do a flying horse, baseball and politicians have in common? Keep reading, and you'll find out. But first, some astronomy! Not long after sunset on Monday evening, gaze toward a low eastern horizon, and you will see a glorious... — Updated 10/4/2021