#sanctuary:astronomy

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Hey, everyone. I just wanted to let everyone know that I will be taking the astronomy club out on the beach tonight for a little stargazing. Anyone that wants to come is more than welcome, and if you have any questions, feel free to let me know. We’ll be talking more about what my previous social media post means, and how it tells you what the night sky will look like in the next few nights, which you can read HERE. 

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Tonight is as good a night as any to finally head out into the courtyard and start things up with the astronomy club. Based on the date and our location on Earth, we’ll be able to see Ursa Major, Ursa Minor, Cepheus, Perseus, Cassiopeia, Draco, Andromeda and more. Although the star Spica, brightest light in the constellation Virgo the Maiden, serves as a prime example of a first-magnitude star, it might be hard to see this star in the glow of evening dusk (especially from northerly latitudes). If you can’t see it, binoculars will help. I’ll be there too, of course, so if you need help you’ll have it. I’ll talk about a few of the mythology stories behind some of the constellations out tonight too, if anyone is interested. 

Did you catch the whisker-thin waxing crescent after sunset August 20th? If you missed the slender young moon at dusk on August 20th and August 21th, you can still try again tonight or tomorrow.  To see a young moon, you’ll want an unobstructed horizon in the direction of sunset. Find a hill or balcony to stand on, enabling you to peek just a little farther over your horizon. Binoculars come in handy, too, when the bright evening twilight will be competing with the tiny, ghostly lunar crescent. As a general rule, it’s difficult to spot a crescent that’s less than 24 hours old (24 hours after new moon). Everywhere around the world, at sunset August 20, the moon will be over one day old. Even so, from much of the world, the slim crescent will follow the sun beneath the horizon before nightfall.  

Day by day after tonight, watch the illumined portion of the lunar crescent grow, and for the moon to stay out longer after sundown. For a special treat, check out the earthshine softly illuminating the dark side of the moon with either the unaided eye or binoculars.

Planets Visible night of Aug 21 – Aug 22, 2020

Mercury:Until Fri 8:49 pm

Venus:From Sat 3:26 am

Mars:From Fri 10:59 pm

Jupiter:Until Sat 3:41 am

Saturn:Until Sat 4:22 am

Uranus:From Fri 11:21 pm

Neptune:From Fri 9:20 pm

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Young moon after sunset September 18-21

Sep 19 - Sep 25 star forecast

18 Young moon after sunset September 18 to 21

21 Year’s fastest sunsets around equinoxes

22 Equinox sun is over Earth’s equator

23 Moon, Jupiter, Saturn September 23-26

26 Mercury in the west after sunset

27 Orion’s Belt points to dazzling Sirius

28 Moon, Fomalhaut in late September

On September 17, 2020, the new moon passed 5 degrees north of the sun to transition out of the morning sky and into the evening sky. On the day of new moon, we didn’t see the moon at all, because it rose and set with the sun (more or less) and so was lost in the sun’s glare throughout the day. But the moon always returns after new moon to the west after sunset, as it will on September 18, 19, 20 and 21. On one or all of these evenings, you’ll spot the young moon, a little crescent.

In the days after new moon, as the moon continues its ceaseless journey around Earth, it’s easy to picture the moon moving east of the sun on the sky’s dome. That’s what our chart at top shows, and it’s what you’ll see if you look in the sky on each of these evenings: the crescent moon a little farther from the sunset.

Will you see the moon on September 18? Generally, it’s hard to spot a moon that’s less than one day old (less than 24 hours after new moon). For almost all the world on September 18, 2020, the moon will be more than one day (24 hours) old at sunset, but not by much. It’ll take a considerable effort to catch the slender crescent, especially because we’re near the Northern Hemisphere’s autumn equinox, the time of year when young moons are hardest to see. Lucky for all of us on Earth, the moon reaches perigee – its closest point to Earth in its monthly orbit – on September 18, 2020. That means the young moon is traveling away from the sun at its maximum orbital speed on September 18. That’s one reason we’re expecting many diligent observers to catch the young whisker-thin waxing crescent moon – from all parts of the world – at evening dusk on September 18.

To maximize your chances of spotting the young moon on September 18, find an unobstructed horizon in the direction of sunset. If you have them, bring along binoculars. Look westward, near the sunset point on the horizon, for a pale crescent shortly after sundown. Don’t dally, though! The September 18 young moon follows the sun beneath the horizon soon after sundown.

Never fear, though. The young moon will return to the evening sky after sunset on September 19, 20, and 21 as shown on our chart.

Each day, a wider and brighter lunar crescent will appear higher in the sky at sunset and stay out longer after sundown.

Want to know the moon’s setting time for your sky? Click on Sunrise Sunset Calendars, remembering to check the moonrise and sunset box.

The day and night sides of Earth one day after new moon (September 18, 2020, at 11:00 UTC). The shadow line at right (crossing eastern Asia) shows where the moon will be one day old at sunset. The line of sunset travels westward (leftward), so all places to the west (left) of this shadow line have an older moon at sunset.

This young moon takes place just a few days before the Southern Hemisphere’s spring equinox and the Northern Hemisphere’s autumn equinox. At sunset on the spring equinox, the ecliptic – annual pathway of the sun, and approximate monthly pathway of the moon – hits the horizon at its steepest angle for the year.

On the other hand, at sunset on the autumn equinox, the ecliptic hits the horizon at its shallowest angle for the year.

Therefore, all else being equal, the Southern Hemisphere has the upper hand for catching any September young moon.

However, this time around, this moon resides somewhat north of the ecliptic. To some degree, the more northerly moon partially takes away the Southern Hemisphere’s advantage and the Northern Hemisphere’s disadvantage. Even so, the Southern Hemisphere enjoys the overall advantage for this September young moon sighting!

This is the view of the young moon from Valdivia, Chile (40 degrees south latitude). The green line represents the ecliptic, which makes a steep angle with respect to the evening horizon as seen from the southern part of Earth’s globe. The steep angle of the ecliptic will make this young moon a lovely sight for Southern Hemisphere observers. What’s more, from southerly latitudes, skywatchers might glimpse the planet Mercury and the bright star Spica in the constellation Virgo the Maiden. The narrow autumn angle of the ecliptic makes seeing Mercury and Spica unlikely from the Northern Hemisphere.

The planet Mercury and the bright star Spica are in the vicinity of the young moon, but these bright lights will be lost in the afterglow of sunset at northerly latitudes. Since Mercury and Spica lodge to the south of the ecliptic, they’re much easier to view from the Southern Hemisphere. We contrast Philadelphia, Pennsylvania, USA (40 degrees north latitude) with Valdivia, Chile (40 degrees south latitude), both of which reside near the same meridian: 75 degrees west longitude.

Philadelphia, Pennsylvania Moon sets 1 hour 10 minutes after the sun on September 18 Mercury sets 48 minutes after the sun on September 18 Spica sets 56 minutes after the sun on September 18

Valdivia, Chile Moon sets 1 hour and 38 minutes after the sun on September 18 Mercury sets 1 hour and 56 minutes after the sun on September 18 Spica sets 2 hours and 21 minutes after the sun on September 18

Looking for a sky almanac? EarthSky recommends …

Bottom line: After sunset on September 18, 19, 20 and 21, 2020, watch for the waxing crescent moon’s return to the western evening sky. Plus, note the earthshine softly illuminating the dark side of the moon.

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Moon and Venus adorn the morning September 13 to 15

On the mornings of September 13, 14 and 15, 2020, look for the waning crescent moon and dazzling planet Venus in the east before sunrise. If you have very good vision, you might even glimpse these bright beauties after sunrise, in a blue, daytime sky. After all, the moon and Venus rank as the 2nd- and 3rd-brightest bodies to light up the sky (after the sun).

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Above: The moon’s orbit around Earth is not a perfect circle. But it is very nearly circular, as the diagram above shows.

UPCOMING LUNAR EVENTS

Year’s closest new moon October 16th (picture above applicable)

Birth of young moon at day’s end, October 17-20

19th Orionid meteors late night until dawn

20th Orionid meteor shower peak tonight!

21st Moon sweeps by Jupiter and Saturn

24th Bright star Deneb transits at nightfall

25th Watch Capella flashing red and green

On October 16, 2020, we have the year’s closest and largest new moon. It’s a prelude to the year’s farthest and smallest full moon – also a Blue Moon, near red Mars – on October 31 (Halloween).

The 2021 lunar calendars are here! See 2021’s lunar phases. Makes a great gift!

The Halloween Blue Moon (blue in name only) near Mars will be fun to see. Meanwhile, we won’t see the October 16 new moon, closest new moon of 2020 and thus a supermoon. We almost never see a new moon (unless there’s an eclipse) because it’s the moon phase that’s most nearly between the Earth and sun for any particular month. New moons travel across the sky with the sun all day, lost in the sun’s glare.

There are a total of 12 new moons in 2020, but this October new moon comes only about 4 hours before the moon sweeps to lunar perigee: the moon’s closest point to Earth in its monthly orbit.

New moon: October 16 at 19:31 UTC (221,797 miles or 356,948 km)

Lunar perigee: October 16 at 23:46 UTC (221,775 miles or 356,912 km)

And thus astronomers will call this October 2020 new moon a perigean new moon.

Moon’s orbit around Earth, seen from above. At new moon, the moon’s nighttime side faces Earth while the illuminated side faces the sun. At the vicinity of new moon, the moon rises and sets with the sun and is lost in the sun’s glare. Notice the full moon, too; it looks full to us because its entire illuminated side – or day side – faces Earth.

So you won’t see this new moon, even though it’s extra close. Yet if you live along a coast, you might notice its impact along the ocean shoreline in the days following new moon. Twice a month – at new moon and full moon – the gravitational pull of the moon teams up with that of the sun to usher in higher-than-usual spring tides. Around the time of a spring tide, the difference between high tide and low tide is especially profound. With this month’s closer-than-usual new moon, we can expect even higher (and even lower) tides in some places. Weather conditions and the shape of the shoreline also play a role; storms around the time of a perigean new or full moon can result in floods.

Astronomers call this sort of tide – influenced by an extra-close moon – a perigean spring tide.

Looking for a tide almanac? EarthSky recommends this.

Spring tides and neap tides coincide with particular phases of the moon.

One fortnight – one-half lunar month – after this perigean new moon, we’ll have the most distant and smallest full moon of the year on Halloween (October 31, 2020). That’s because of this year’s 13 full moons, the October 31 full moon comes the closest to aligning with lunar apogee: the moon’s farthest point in its monthly orbit around Earth.

At a distance of 252,380 miles (406,166 km), this Halloween full moon is better than 30,000 miles (49,000 km) farther than the October 16 new moon.

Sometimes the year’s smallest full moon (apogean full moon) is called a micro-moon. This year, however, this micro-moon will also be called a Blue Moon, because it’ll be the second of two October 2020 full moons.

Read more: Blue Moon and red Mars on Halloween!

Bottom line: October 16 brings us the closest new moon of 2020. Some will call it a supermoon. You won’t see this extra-close new moon because it’ll travel across the daytime sky with the sun. But you might see its gravitational effect on the tides along ocean shorelines in the days following new moon. Watch for the perigean spring tide to give more loft to high tide, and more depth to low tide.

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update for sept 11 {astronomy club}

The planet Neptune reaches opposition today at 4 P.M. EDT. At that time, Earth will sit between Neptune and the Sun, offering excellent views all night long of the farthest planet from our star. You can find the blue-tinged world in Aquarius the Water-bearer, rising around sunset and gaining altitude as darkness falls. Its disk spans 2.3" and shines at magnitude 7.9, visible in either binoculars or a telescope. The planet will be visible all night and into tomorrow morning, setting around sunrise.

Neptune is currently about 2° east of magnitude 4.2 Phi (φ) Aquarii, which provides us with a chance to press fast-forward on the life cycle of the Sun. Phi is roughly 265 times brighter than the Sun and its radius stretches out to nearly 39 times our own star’s, or half the size of Mercury’s orbit. It’s a red giant star that matches nearly exactly the predictions of astronomers for the condition of our own Sun once it reaches an age of 12 billion years, when it will no longer fuse hydrogen into helium in its core. Eventually, both will evolve into a beautiful planetary nebula, before fading out and leaving behind a tiny white dwarf behind.  

Sunrise*: 6:38 A.M.

Sunset: 7:15 P.M.

Moonrise: 12:04 A.M.

Moonset: 3:31 P.M.

Moon Phase: Waning crescent (37%)

*Times for sunrise, sunset, moonrise, and moonset are given in local time from 40° N 90° W. The Moon’s illumination is given at 12 P.M. local time from the same location.

On September 11, 2020, Neptune reaches opposition, when it is 180 degrees from the sun in our sky. In other words, Earth passes more or less between Neptune and the sun, as we do every year in our yearly orbit. Also, on September 11, Earth and Neptune are closest together for the year.

By closest, I don’t mean close. Neptune, the eighth planet outward from the sun, lodges in the outskirts of our solar system. Its current distance is about approximately 2.7 billion miles (4.3 billion km).

For any superior planet – that is, for any solar system planet beyond Earth’s orbit – opposition is a special event. When any planet outside of Earth’s orbit is at or near opposition, Earth comes closest to that planet for the year, and that planet, in turn, shines most brightly in our sky. Even at opposition, however, Neptune, the eighth planet, is not bright. In fact, Neptune is the only major solar system planet that’s absolutely not visible to the unaided eye. This world is about five times fainter than the dimmest star that you can see on an inky black night. You’ll need binoculars (at least) and a detailed sky chart to see Neptune in front of the constellation Aquarius.

Here is a detailed chart showing Neptune

Because we’re more or less between Neptune and the sun around now, Neptune is rising in the east around the time of sunset, climbing highest up for the night around midnight and setting in the west around sunrise. As viewed from Earth now, this world is in front of the constellation Aquarius the Water Carrier, right next to the 4th-magnitude star Phi Aquarii.

Phi Aquarii, though faint, is easily visible to the eye alone on a dark night. Because the moon is now a waning crescent, the moon-free evening hours offer a dark sky for viewing Neptune.

Neptune and Phi Aquarii are so close together on the sky’s dome at present that the two readily fit within a single binocular field. In fact, you might see them together in a low-powered telescope, with blue-green Neptune offering a color contrast to the ruddy tint of Phi Aquarii. Neptune is nearly 30 times fainter than the star Phi Aquarii. You may well be able to view Neptune with this star tonight.

Even with an optical aid, Neptune may look like a faint star. You need to magnify Neptune by about 200 times and have a steady night of seeing to view this distant world as a small disk.

By the way, if Earth and Neptune both orbited the sun in perfect circles and on the same plane, then Neptune would be closest to Earth right at opposition. Yet, the Earth actually comes closest to Neptune some 19 hours before Neptune’s opposition. That’s because, at opposition, the Earth is a bit closer to the sun (and, therefore, farther from Neptune) than the Earth was 19 hours before opposition. Neptune is also closer to the sun at opposition than 19 hours before. But Earth’s change in distance is much more significant than that of Neptune.

Bottom line: Neptune’s opposition – when it’s 180 degrees from the sun on the sky’s dome – comes on September 11, 2020. You need optical aid to spot it. 

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Oct 9-Oct 15 star guide

09 Last quarter moon in Gemini, waning moon in Cancer

11 Moon, Venus, Regulus October 12 to 15

12 Mars to reach opposition October 13

14 Autumn’s false dawn, the zodiacal light

15 Summer Triangle and galactic equator

16 Year’s closest new moon October 16

17 Birth of young moon at day’s end, October 17-20

Wake up before dawn on the mornings of October 10 and 11, 2020, and let the waning moon show you the zodiacal constellations Gemini and Cancer.

Before midnight October 9, 2020 – or after midnight October 10 – the moon will be rising over your eastern horizon at or near its half-illuminated last quarter phase. It’ll be shining in front of the constellation Gemini the Twins. If you’re more of an early bird than a night owl, get up before dawn to view the moon and Gemini much higher up in the sky. To the north of the moon will be Gemini’s two brightest stars, Castor and Pollux. The other bright star beaming to the south of the moon will be Procyon, the Little Dog Star.

The moon’s exact last quarter phase comes on October 10, 2020, at 0:39 UTC. Although the last quarter moon occurs at the same instant worldwide, the local clock time – and possibly the date – differ by time zone. Depending on where you live worldwide, the last quarter moon falls on October 9 or 10.

The constellation Gemini via the IAU. Every year, the sun passes in front of this constellation from about June 21 to July 20.

Although the sky chart at the top of this page is designed for temperate latitudes in North America, you’ll see the moon passing through the same region of the starry sky from all parts of Earth. The moon moves in front of the constellations of the zodiac at the rate of about 1/2 degree (the moon’s own angular diameter) eastward per hour. So – for example – if you’re in the world’s Eastern Hemisphere at dawn on October 10 and 11, you’ll see the moon offset a bit, with respect to our chart, toward the previous date.

The lit side of a waning moon always points eastward – the moon’s direction of travel – in front of the backdrop stars of the zodiac. On the morning of October 10, from around the world, the moon’s daytime side will be pointing at the hidden treasure at the heart of the constellation Cancer the Crab: a star cluster known as Messier 44, or M44, aka the famous Beehive. Then, on October 11, the moon will sweep 2.1 degrees north of the Beehive at 12:27 UTC.

Click here to know the moon’s present position in front the constellations of the zodiac.

The constellation Cancer via the IAU. On a dark night, look for the Beehive star cluster (M44) to make a triangle with the Gemini stars, Castor and Pollux, and the bright star Procyon.

As seen from North America on the morning of October 11, the moon will meet up with the Beehive at 8:27 a.m. EDT, 7:27 a.m. CDT, 6:27 a.m. MDT and 5:27 a.m. PDT. Cancer makes up for its lackluster stars by sporting one of the most magnificent star clusters in all the heavens. On a dark night – with no moon – this cluster appears as a tiny faint cloud to the unaided eye. Through binoculars, this bit of haze explodes into a sparkling array of stars.

Bottom line: Last quarter moon comes on October 10, 2020. That morning, the moon will be in front of Gemini the Twins. The next morning – October 11 – the moon will be in front of Cancer the Crab.