Borrego Sun - Since 1949

Articles written by Dennis Mammana

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 By Dennis Mammana    News 

Moon and Venus at Dusk

Have you noticed the remarkable jewel sparkling low in the western sky after sunset? That is the planet Venus, returning to the evening sky after being visible for many months only to pre-dawn risers. Some may have missed it... — Updated 6/14/2021

 
 By Dennis Mammana    News 

Shadow on the Moon

During the early morning hours of May 26, night owls and early risers will enjoy a beautiful eclipse of the moon. The celestial cover-up begins at 2:45 a.m. PDT (5:45 a.m. EDT) when the moon's eastern edge will enter the Earth's... — Updated 6/10/2021

 
 By Dennis Mammana    News 

A Lunar Eclipse Sneak Preview

Early on the evening of Tuesday, May 25, watch as the sun sets behind the western horizon; then, face the opposite direction and you'll soon spot the moon rising in the east. On that night, the moon's phase will be full, and... — Updated 6/7/2021

 
 By Dennis Mammana    News

Why Is the Night Sky Dark?

If you're out looking for the moon this week, you'll have a tough time finding it. On May 11, it lies nearly in the direction of the sun (its "new moon" phase), but by May 13, it will appear as a thin crescent low in the western... — Updated 5/21/2021

 
 By Dennis Mammana    News

Seeing Halley's Meteors

Halley's Comet hasn't appeared in our sky for a quarter-century, but during the pre-dawn hours of May 6, stargazers will have a chance to see pieces of this famous celestial visitor. On that morning, sky watchers far from city... — Updated 5/19/2021

 
 By Dennis Mammana    News

Why Doesn't the Moon Rotate?

Here we are, already at the end of April, and with this season comes some beautiful evening weather to help us enjoy our night sky viewing. This week, the full moon illuminates our sky on Monday, April 26, and as the full moon... — Updated 5/4/2021

 
 By Dennis Mammana    News

Mars Perseverance: Why Bother?

By Dennis Mammana If you haven't been paying attention to the Perseverance spacecraft that landed on Mars on Feb. 18, you've been missing one of the great scientific achievements of our time. Check out the real-time video of its... — Updated 4/29/2021

 
 By Dennis Mammana    News

The Herdsman and the Crown

I always know that springtime has arrived by the stars I see during the early evening hours. One of my favorites is the small but quite beautiful constellation Corona Borealis, the Northern Crown. The Northern Crown isn't one of th... — Updated 4/23/2021

 
 By Dennis Mammana    News

The Celestial Water Snake

Springtime in the Southern California deserts is when the snakes begin to appear. They're beautiful creatures, of course, but considering how much time I spend prowling around after dark, I'm always concerned that I might... — Updated 4/6/2021

 
 By Dennis Mammana    News

Listen to the Moon

There's an old joke that I just love to tell. An elementary school teacher was presenting a lesson about the moon and asked the children which is more important, the sun or the moon, figuring the answer was obvious. After all, the... — Updated 4/1/2021

 
 By Dennis Mammana    News

Star Patterns Made Easy

I recall many years ago standing under the stars trying to figure out why the starry heavens looked nothing like the elaborate drawings I'd seen in star maps and books. Why could I never find a bear among the stars of Ursa Major,... — Updated 3/25/2021

 
 By Dennis Mammana    News

Seeking the Zodiacal Light

Stargazers who spend time in rural locations get to experience celestial sights that are invisible, and sometimes completely unknown, to those living near the bright lights of a city. For example, the number of stars scattered... — Updated 3/24/2021

 
 By Dennis Mammana    News

Seeing History... in Real Time

It's been said that most of our knowledge of the universe comes to us in the form of light. But just what is light? Well, that's a question that scientists have pondered for ages, and the answer seems quite peculiar. We now know... — Updated 3/17/2021

 
 By Dennis Mammana    News

Sneak Peek at the Summer Sky

If you’re like I am, you long for summertime, not only for its warm weather and abundant growth but also because its nighttime sky is among the richest of the year. So it’s usually around late February that I begin wandering outdoors before dawn to sneak a peek at the stars... — Updated 3/3/2021

 
 By Dennis Mammana    News

Seeing the Sun at Night (Well, Sort Of)

Stars are not all alike. If they were, we could determine their relative distances just from how bright they appear. They do share one important similarity, however: Each is a thermonuclear furnace. In most cases, the cores of the... — Updated 3/3/2021

 
 By Dennis Mammana    News

Hare-y Tales of the Winter Sky

If you haven't been out to enjoy a dark night sky this winter, you'll be happy to learn that few activities can keep you more socially distanced than stargazing. The stars are so brilliant right now not because of the frosty night... — Updated 3/3/2021

 
 By Dennis Mammana    News

The Return of the Big Dipper

Scientists tell us that our sense of smell is one of the most powerful memory triggers. Get a whiff of a freshly mown lawn or a turkey roasting in the oven and I'll bet you agree. For me, there's another memory trigger that seems... — Updated 2/19/2021

 
 By Dennis Mammana    News

How Far South Can You See?

This week I spotted the star Canopus for the first time since last winter, and I was reminded of an interesting fact. Quite a few folks still believe the Earth is flat. Hard to believe, I know. Many of these people belong to the... — Updated 2/8/2021

 
 By Dennis Mammana    News

When Celestial Giants Meet

If you've got a small backyard telescope, this is the time to set it up, because next week, you'll witness something you may never witness again. On the evening of Dec. 21, stargazers looking low toward the southwestern sky during... — Updated 1/28/2021

 
 By Dennis Mammana    News

The 'Linking' Star

Many folks believe that constellations are celestial pictures and are disappointed when they can't see these fanciful images from ancient times. That's because constellations are not pictures but areas of the sky. Astronomers have... — Updated 1/27/2021

 
 By Dennis Mammana    News

2021: A Year of Celestial Wonder

The beginning of each new year is filled with hope and optimism. This year will be no exception, especially after the gut-punch we received from 2020. And with the new year comes a list of resolutions we swear we’ll follow. How many times can we possibly say, “And this year, I... — Updated 1/11/2021

 
 By Dennis Mammana    News

Mooning Around on Winter Nights

The final full moon of 2020 arrived on Dec. 29, when it rose majestically over the northeastern horizon shortly after sunset. We astronomers usually schedule our observing programs for times when the sky isn't obscured by such... — Updated 1/8/2021

 
 By Dennis Mammana    News

Which Astronomy Books are the Best?

One of the most common questions I hear around the holiday gift-giving season is this: "Which is the best book to buy for a beginning stargazer?" I wish it were that easy, but the fact is I just have no answer! Unfortunately,... — Updated 12/31/2020

 
 By Dennis Mammana    News

Geminids Meteor Shower

I was well into adulthood before I ever considered spending an entire night outdoors during December. Once I moved from the U.S. East Coast to a more temperate climate, however, I did this frequently. Why? Because I've since... — Updated 12/11/2020

 
 By Dennis Mammana    News

Penumbral Lunar Eclipse

Did you ever wonder what folks During the predawn hours of Nov. 30, night owls and insomniacs in North America may see an eclipse of the moon as our nearest natural satellite drifts through the Earth's shadow as it orbits our... — Updated 12/11/2020

 

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