Latest / Star Trails: From Backyard Astronomy to Cosmic Wonder / Autumn Arrives, Stargazing Adventures on Vacation
Transcript
- Howdy stargazers, and welcome to this episode of Star Trails. My name is Drew and I’ll be your guide to the night sky for the week starting September 22nd to the 28th. This week we mark the beginning of fall with the autumn equinox. That means the start of longer nights, perfect for stargazing. And it’s a great week for checking out the night sky – the moon is waning, a cavalcade of planets are on the rise, and fall’s deep sky objects are beginning to make their presence known. Stick around for the second half of the episode, and I’ll describe how I was able to get in some astronomy while I was traveling in the Pacific Northwest and Alaska. Plus, what I’ve been reading. If you’re a fan of the history of astronomy, Einstein, Newton, and planet-hunting, I have a book I think you’ll enjoy. So grab your observational instrument of choice, a comfortable chair, and let’s get started. Some of the best nights for stargazing are right around the corner. Last week the spectacular Harvest Supermoon lit up the night sky, and we’ll begin this week with the moon in a waning gibbous phase, which is still quite bright. But by the end of the week, the moon will be a slender crescent, well on its way towards the New Moon, and as you know, this means darker skies for hunting down deep sky objects and the bands of the Milky Way, right up until October 7, so make the most of this observation window if you can. Saturn will be visible all night long during this period. It’s been at opposition, meaning it’s bright and easy to spot. Look for it in the southeastern sky after sunset, where it shines as a yellowish dot in the constellation Aquarius. If you have a telescope, you’ll get great views of Saturn’s rings, which are still in that unique edge-on orientation to Earth. There’s a lot of planetary action around Taurus and Gemini this week. Jupiter will be rising later in the night, around midnight, and will be visible in the southeastern sky in the early morning hours before sunrise. You’ll find it near the bright stars Aldebaran and Betelgeuse, forming a striking triangle with them. The clearest telescopic views of Jupiter come after midnight or when it is very high around morning twilight. Keep in mind, objects closer to the horizon often experience atmospheric turbulence that can make for fuzzier views through a scope. Mars can also be spotted in the early morning hours, moving toward the constellation Gemini. On the morning of September 25, the crescent moon will pass near Mars, making for a beautiful sight. Early in the week, the Moon will be very near both the Pleiades star cluster and Jupiter. Look for that alignment after midnight on the morning of the 23rd. Cassiopeia is one of the most easily recognizable constellations in the night sky, especially during the fall and winter months in the Northern Hemisphere. Its distinctive “W” or “M” shape (depending on its orientation in the sky) is formed by five bright stars and makes it stand out against the backdrop of the Milky Way. Located near the celestial North Pole, Cassiopeia is circumpolar, meaning it never sets below the horizon for most observers in northern latitudes, making it visible year-round. In Greek mythology, Cassiopeia was the vain queen of Ethiopia, married to King Cepheus and mother to Andromeda. Her beauty was legendary, but her arrogance caused trouble. Cassiopeia boasted that she was more beautiful than the Nereids, sea nymphs who were favored by Poseidon, the god of the sea. In retaliation, Poseidon sent a sea monster to ravage the kingdom. As part of her punishment, Cassiopeia was placed in the heavens, tied to her throne. She circles the celestial pole, and for part of the night, she is upside down, a symbol of her eternal punishment for her vanity. The five main stars of Cassiopeia form the well-known “W” shape, each with its own unique characteristics: Schedar is the brightest star in the constellation. An orange giant located about 230 light-years away. Its name is derived from the Arabic word for “breast,” as it was thought to represent the heart of the queen. Caph is a white giant star located around 54 light-years away. It’s a variable star, meaning its brightness fluctuates slightly over time. Caph marks the top right point of the “W.” The central star of the "W," Gamma Cassiopeiae is a rapidly rotating blue-white subgiant. Its high speed causes material to be ejected from the star, forming a disk around it. Its brightness can vary significantly over decades. Ruchbah, forming the lower left of the “W” is a binary star. Finally, Segin is a blue giant, and the faintest of the five main stars.. Cassiopeia is also home to some fascinating deep sky objects, although some of them are challenging to spot. The Double Cluster (NGC 869 and NGC 884), located between Cassiopeia and the constellation Perseus, is a pair of open star clusters that can be spotted with binoculars. These clusters are about 7,500 light-years away and are believed to be around 12.8 million years old. The Heart and Soul Nebulae (IC 1805 and IC 1848) are a pair of neighboring emission nebulae where new stars are forming. They are found near the constellation’s border with Perseus and are best seen through long-exposure photography owing to their faintness. Cassiopeia A is the aftermath of a massive star that exploded around 300 years ago. While the remnant itself is not visible to the naked eye, it’s a popular target for radio telescopes and offers valuable insight into the life cycle of stars. During September, Cassiopeia is high in the northeastern sky during the evening, making it a great target for stargazers. If you’re on the hunt for deep sky objects, The constellation Lyra will be high in the sky. Lyra is home to the famous Ring Nebula (M57). This is a great opportunity to explore this planetary nebula with a telescope. Also, look for the Andromeda Galaxy (M31) near Pegasus. This is the closest large galaxy to our Milky Way and can be seen as a faint, blurry patch with the naked eye in very dark conditions. I hope you don’t mind if I digress a bit and talk about a recent trip I took to Alaska. I won’t bore you with all the details, but to keep a long story short, I was able to do more stargazing on this trip than I have been able to do at home. The sun was setting as we flew west towards Vancouver, I was stunned by the sight of a thin crescent moon hovering over the dark storm clouds we were flying over. The moon looked massive, both because it’s currently in perigee with the Earth, and because of the “moon illusion” where objects near the horizon seem larger. Then, things got more interesting. I had my first Venus sighting of the season, extremely bright and even lower on the horizon than the moon. Thanks to the cruising altitude of 36,000 feet, I enjoyed clear skies for this spectacle. In southeastern Alaska, parts of which are technically a rainforest, clear skies were definitely not the norm. According to the locals I spoke to, it rains nearly every day, and indeed, skies were cloudy. Then one evening, just before midnight, the clouds drifted away and the Northern Lights erupted in the night sky. The Big Dipper was prominent in the sky as shades of green and pink swirled across Polaris, over to the Pleiades. The next evening was also clear and I managed to photograph the nearly full Harvest Moon rising over the mountains of the inland passage, reflecting in the waterway below. Vacations are often a time to escape, unwind, and explore new places. But for those who love astronomy, they can also offer incredible opportunities to stargaze and explore the night sky from a whole new perspective. Whether you’re flying at 30,000 feet or cruising through the ocean, your vacation can double as an astronomy adventure. Like I mentioned earlier, some interesting stargazing opportunities can happen while you're mid-flight. At cruising altitudes there’s significantly less atmosphere to look through, which means the stars, planets, and the moon can appear much clearer than they do from the ground. On a night flight over a dark ocean or remote regions, it's worth peering out the window for a chance to see stars twinkling brighter than usual. If your flight path takes you near the Earth’s poles, you might catch a glimpse of aurora. Vacations often take us to remote and beautiful locations—whether it's a secluded beach, a mountain cabin, or a desert escape. These places can be far from the light pollution of cities, making them perfect for stargazing. More than 20 years ago, I was in Australia, in a small town called Ngambie, about an hour outside Melbourne, but not quite in the outback. Those were some of the clearest skies I’ve ever seen, and it was fascinating to see the sky of the southern hemisphere, which is quite different from what we see here in North America. If you're heading to a national park on your vacation, you may be in one of the best spots for stargazing. Many parks in the United States and around the world are designated as International Dark Sky Parks, meaning they’re protected from light pollution to preserve the natural night sky. This makes them perfect for astronomy enthusiasts. Some great examples include: Bryce Canyon National Park in Utah is famous for its striking rock formations by day and awe-inspiring night skies. Big Bend National Park, situated in a remote part of Texas, offers some of the darkest skies in the continental United States. Jasper National Park in Alberta, Canada is one of the largest dark sky preserves in the world, and provides a magnificent view of the Milky Way. It’s also a great spot to watch meteor showers. Cruise vacations also offer fantastic stargazing opportunities. When you're far out at sea, away from city lights, the sky can be incredibly dark, providing crystal-clear views of the stars. Many cruises even offer onboard astronomy programs where experts guide passengers through the night sky. The endless horizon of the ocean creates a perfect backdrop for connecting with the cosmos. Don’t forget your binoculars. They are easy to pack in a suitcase, and can also be excellent for observing the Moon’s craters, or spotting open star clusters like the Pleiades. When you aren’t using them for astronomy, they’ll be useful for sightseeing, checking out scenery, or watching for native wildlife. Remember to use an astronomy app like SkySafari or Stellarium to enhance your experience. These apps are especially useful if you're unfamiliar with the night sky in your vacation destination. Simply point your phone or tablet toward the sky, and these tools will guide you through the constellations overhead. And finally, I wanted to mention what I’ve been reading lately. It’s a long title, but I’ll include a link in the show notes. The book is called The Hunt for Vulcan: . . . And How Albert Einstein Destroyed a Planet, Discovered Relativity, and Deciphered the Universe, and it’s by Thomas Levenson. The book deals with the issue of the “precession of Mercury’s perihelion” – that is, its slightly irregular orbit around the sun – and how past astronomers believed another planet was between the Sun and Mercury, whose gravitational influence was somehow creating the orbital anomaly. The hunt for the so-called planet, Vulcan, bothered astronomers for decades, and this book describes their efforts in locating it. Well, spoiler alert – and I don’t think I’m giving away the ending, because it’s right there in the title – we never found Vulcan. Anyone who has looked at Einstein’s Theory of General Relativity may recall that the problem of Mercury’s orbit was explained as an effect of the curvature of spacetime around the Sun. The book will, of course, explain it a lot better than I can, and along the way, you’ll learn about how orbital mechanics, and in particular, Newtonian physics, helped astronomers locate both Uranus and Neptune. There’s very little math and it’s an easy read. So if you’re a fan of books such as A Brief History of Time, you won’t have any trouble following along. Much like a vacation, the journey is as important as the final destination, so even if you know how this story ends, you’ll pick up a lot of good anecdotes and astronomy history along the way. That's it for today’s episode of Star Trails. Remember, we’re also on Mastodon @star_trails. If you get a chance, stop by and say hello. I’ll include a link in the show notes. Also, remember our website, startrails.show, where you can find all our episodes, including transcripts and night sky maps. Until next time, keep looking up and exploring the night sky. Clear skies, everyone!