#pm ganymede

[taiyokei]

Some Ganymede and Luna sketch I made as a post response on twitter!

[ganymedevt]

🌹GANYMEDE IS GOING TO KOMIKET QC!🌙

You can find my catalog and map here! Boothing with my beloved @veoxylia for beefrog studios' debut con💜

📌 Booth 162, Centris Elements, QC 🌟 Feb 10-11, 9 AM to 7 PM 🎟️ Php100

See you there, seelies!

[spacetimewithstuartgary]

SwRI-led instrument aboard Jupiter-bound spacecraft nails in-flight test

As European Space Agency (ESA)’s Jupiter Icy Moons Explorer (Juice) spacecraft hurtled past the Moon and Earth in mid-August to provide its first gravity assist maneuver to the Jovian system, the Southwest Research Institute-led Ultraviolet Spectrograph (UVS) instrument imaged the UV emissions radiating from the Earth and Moon.

It was a successful test of one of three science instrument projects comprising NASA’s contribution to ESA’s Juice mission. The UVS data collected were then analyzed and found to be consistent with expectations for the Moon and the Earth. This confirmation that the instrument works within specifications was not able to be fully achieved during pre-launch testing in a laboratory setting.

“This high-fidelity test confirmed what the instrument is supposed to do. We can now be confident that the data we will get from Jupiter’s moons will be just as accurate,” said SwRI’s Steven Persyn, Juice-UVS project manager (PM).

Weighing just over 40 pounds and drawing only 7.5 watts of power, UVS is smaller than a microwave oven, yet this powerful instrument will determine the relative concentrations of various elements and molecules in the atmospheres of Jupiter’s moons once in the Jovian system.

Aboard Juice, UVS will get close-up views of the Galilean moons Europa, Ganymede and Callisto, all thought to host liquid water beneath their icy surfaces. UVS will record ultraviolet light emitted, transmitted and reflected by these bodies, revealing the composition of their surfaces and tenuous atmospheres and how they interact with Jupiter and its giant magnetosphere. Additional scientific goals include observations of Jupiter itself as well as the gases from its volcanic moon Io that spread throughout the Jovian magnetosphere.

The Juice spacecraft is now on its way to Venus, where it will complete a gravity assist maneuver before heading back to Earth for another gravity assist to attain the momentum needed for its journey to the Jovian system.

The mission’s science goals focus on Jupiter and its system, making multiple flybys of the planet’s large, ocean-bearing satellites with a particular emphasis on investigating Ganymede as a potentially habitable planetary body. Being the only moon in the solar system known to have an internal magnetic field, Ganymede has auroral ovals like the northern and southern lights on Earth. The UV emissions from Earth’s atmosphere observed during the recent gravity assists provide an especially good test of the plans for Juice-UVS to observe Ganymede’s UV aurora and other atmospheric features. It will also study the system as an archetype for gas giants in our solar system and beyond.

UVS is one of 10 science instruments and 11 investigations on the Juice spacecraft. As it begins an approximately 4.1-billion-mile (6.6-billion-kilometer), eight-year journey to the Jupiter system, the spacecraft has been busy deploying and activating its antennas, booms, sensors and instruments to check out and commission all its important subsystems. SwRI’s UVS instrument is the latest to succeed in this task.

A similar instrument, Europa-UVS, will travel aboard NASA’s Europa Clipper, which will take a more direct route to arrive at the Jupiter system 15 months before Juice and focus on studying the potential habitability of Europa.

“Our UVS instrument will complement the work that will be done by Europa-UVS allowing us to learn even more at the same time,” said SwRI’s Dr. Kurt Retherford, principal investigator (PI) of Europa-UVS and deputy PI for Juice-UVS. “Having both teams working with the UVS instruments based here at SwRI will make that coordination all the more efficient.”

The Juice spacecraft and science instruments were built by teams from 15 European countries, Japan and the United States. SwRI’s UVS instrument team includes additional scientists from the University of Colorado Boulder, the SETI institute, the University of Leicester (U.K.), Imperial College London (U.K.), the University of Liège (Belgium), the Royal Institute of Technology (Sweden) and the Laboratoire Atmosphères, Milieux, Observations Spatiales (France). The Planetary Missions Program Office at NASA’s Marshall Space Flight Center oversees the UVS contribution to ESA through the agency’s Solar System Exploration Program. The Juice spacecraft was developed by Airbus Defence and Space.

IMAGE: The UVS instrument recorded spatial information produced by hydrogen atoms radiating from the Earth. In the background a number of individual stars are identified along with the Pleiades star cluster. Juice-UVS plans to similarly observe hydrogen atoms radiating from Ganymede and Jupiter’s other icy moons. Credit Southwest Research Institute

[travelnew]

Jupiter with Callisto (top) and Ganymede (bottom) on 9 Feb 2024 at 9:19 pm, clicked through a mobile phone.

[spacenutspod]

The Galilean Moons, named in honor of Galileo Galileo, who first observed them in 1610, are a fascinating collection of satellites. For decades, scientists have been immensely fascinated by the three icy companions – Europa, Ganymede, and Callisto – which have oceans in their interiors that possibly support life. But Io has also been a focal point of interest lately, owing to the volcanic activity on its surface and lava plumes reaching 300 to 500 km (186 to 310 mi) into space. Since 2016, NASA’s Juno probe has provided stunning images of Io as it continues to orbit its main science objective, Jupiter. The latest was acquired by the Juno probe’s main camera (JunoCam) on July 31st, 2023, at 05:03 AM UTC (01:03 AM EDT; July 30th, 10:03 PM PDT) and showed Prometheus spewing out lava. This active volcano is located within a 28-km (17-mi) -wide volcanic pit named Prometheus Patera on the hemisphere facing away from Jupiter. Prometheus is known for its regular eruptions, hence its nickname in the astrogeological community, “Old Faithful of Io.” A processed image of the eruption was shared by the NASA Planetary Science Division via Twitter (see below). Fresh from Jupiter, we have new views of its active moon Io, thanks to the #JunoMission. JunoCam even caught a glimpse of a volcanic plume! This is Prometheus, the "Old Faithful of Io." More images: https://t.co/1Vm8NwGA6R pic.twitter.com/YpTAf6IJCu— NASA Solar System (@NASASolarSystem) August 4, 2023 The image was taken during Juno‘s fifty-third orbit of Jupiter (perijove 53), where the probe once again circled the gas giant from pole to pole. During this latest pass, the Junocam science team took many images to look for lightning storms in Jupiter’s atmosphere, cyclones in the polar region, and filamentary clouds and jets. The probe also made its closest pass to Io during perijove 53, coming within 22,000 km (13,700 mi) of the moon’s surface. During the past few flybys, the probe has been getting progressively closer to the volcanic satellite. During its previous flyby of Io on May 16th, the Juno probe passed within 35,600 km (22,100 mi) of the surface. On this occasion, JunoCam captured images of the Volund region near the equator, famous for its two active volcanoes (Volund A and Volund B), that showed evidence of eruptions. This was indicated by what appeared to be “smudges” on the landscape, which scientists consider a “smoking gun” for outgassing associated with volcanic plumes. The mission controllers decided to take advantage of this latest and closest flyby to examine Io’s surface and gather more data on its many volcanic regions. In addition to the pictures taken by the JunoCam, extensive information was collected by the Jovian InfraRed Auroral Mapper (JIRAM), provided by the Italian Space Agency (ASI), and other science instruments. This latest batch of data is expected to provide additional insight into the hundreds of volcanoes regularly pouring molten lava and sulfurous gases all over the moon’s surface and its tenuous atmosphere. While Io’s volcanoes have been imaged repeatedly over the past three decades by three NASA spacecraft (Galileo, New Horizons, and Juno), scientists are still excited to see new pictures of eruptions on the moon. While the Juno probe’s primary mission was originally planned to last four years (until 2020), the mission has since been extended twice- first to July 30th, 2021, and again until September 2025. Juno is expected to make two more close passes to Io, coinciding with Perijove 57 and 58. Hopefully, we will see more images of Io’s wild, erupting surface (optical and thermal, please!) The raw images are available on the JunoCam website and other versions of the data product, all of which are available for download and processing. The JunoCam is overseen by researchers at the Southwest Research Institute (SwRI) in San Antonio, Texas. Further Reading: NASA The post Juno Shares Stunning New Images of Jupiter’s Volcanic Moon Io appeared first on Universe Today.

[humanspaceflightday]

Yuri’s Night is a global initiative to popularize topics related to humanity’s cosmic past, present, and future. Traditionally, we at Ratio join the program, and this time we have prepared a series of interesting topics that we will fly through together. The crew we invite you to join includes two speaker stars who you have met on our stage before: Viktor Danchev and Stoil Ivanov. With them, we will circle three main themes, and in the meantime, we will have fun with a special thematic selection of music suitable for a space party.

To the moon and beyond 12 people stepped onto the surface of another celestial body between 1969 and 1972. To this day, it is one of the greatest achievements of NASA and humanity in general. But despite this promising start, Earthlings’ space expansion seems to be on indefinite hiatus…

What can we learn from the great Space Age of the 20th century, and are these lessons applicable today?

Are private space projects the solution and what can we expect from them in the near future?

How are things changing in the aerospace industry today?

What effects do new technologies have on gear, spacesuits, rockets, and everything else?

Hunting for water. The European Space Agency’s JUICE mission will undertake detailed observations of Jupiter’s icy moons – Ganymede, Callisto, and Europa. Equipped with a wide range of observational instruments, the spacecraft will give us valuable information about the conditions of these satellites and the potential possibilities for life on them. We will talk about the mission and discuss:

What are the plans for Juice and what are the expectations of the experts?

What does the path to Jupiter look like and how are the gravitational fields of various objects used to get there faster and more efficiently?

How can the study of Jupiter and its system of moons become a basis for the study of other gas giants in the universe?

Cosmos like in a movie Space invites not only explorers but also artists. Some of the most beloved blockbusters in history, from 2001: A Space Odyssey to Interstellar, are filled with epic cosmic vistas, bold visions of the future… and no small amount of creative wilfulness… We take a look at some of cinema’s favorites -Space to discuss:

Which movies best represent space and our journey through it?

Which titles do scientists dislike the most?

In fact, how important is scientific precision in the art world?

Yuri’s night 2023 - Sofia, Bulgaria;

When: 2023-Apr-12

Time: 07:00 PM (PDT) - 10:30 PM (PDT)

Location: KUPE / КУПЕ, Passage / Yard, ulitsa "Slavyanska", Sofia, Bulgaria.

[planetaryshitpost]

ganymede is trying his hardest

[abookishdreamer]

Character Intro: Ditus (Kingdom of Ichor)

Nicknames- Ditus by the others in the pantheon

Age- 19 (immortal)

Location- Chant du Cygne neighborhood, New Olympus

Personality- They say it best, self-describing themself as a "beautiful chaotic mess swirling with masculine & feminine energy." They're quiet and thoughtful, and don't mind being a livewire. Their relationship status is currently "confusing."

*Even though there's no distinct preference towards specific pronouns, Ditus generally goes by he/they.

He has the standard abilities of a god. He has the power of flight due to his large wings (one wing is light blue with pink streaks while the other is light pink with blue streaks). As the god of bisexuality, effeminacy, fertility, & unions Hermaphroditus has several abilities like limited amokinesis, pheromone manipulation, having the power to affect a women's fertility cycle (inducing symptoms like PMS, cramps, bloating) and having an innate sense a person's fertility levels (& how likely they are to become a parent). He can also curse an opponent's reproductive organs, causing a burning sensation and he can curse an opponent to mentally switch genders, temporarily.

They have identifications of being bigender, gender fluid & non-binary.

Ditus lives in a mansion in the Chant du Cygne neighborhood of New Olympus, just a few minutes away from their good friend Ganymede (god of homosexual love & desire). Inside, the color scheme is blue, pink & purple. There's also a connecting workshop, where they work on their sculptures.

In the pantheon, he's also good friends with Pannychis (goddess of nightlife festivities), Aether (god of the upper atmosphere, celestial bodies, & heavenly light), Móda (goddess of fashion), Komos (god of revelry), Phaenna (goddess of jewels), Aerin (goddess of the ethereal); they've been close even before her transition, Iris (goddess of the rainbow), Peitho (goddess of persuasion & sensuality), Naeus (god of weddings), Chrysos (god of gold & riches), The Graces, Aphrodite (goddess of love & beauty), Gelos (god of laughter), Hermes, Adephagia (goddess of gluttony), The Muses, Nerissa (goddess of jellyfish), Aeolus (god of wind), Dionysus (god of wine), Mania (goddess of insanity), Pothos (god of longing & yearning), Apollo (god of the sun, music, poetry, healing, medicine, archery, plague, light, & knowledge), and Himeros (god of impetuous love). His friendships are really important to them.

Ditus does think that Hedylogos (god of sweet talk & flattery) & Horme (god of energy) are a bit too immature.

Ditus really admires Philotes (goddess of sex, friendship, & affection).

Their go-to drink is a triple berry margarita (a drink made with triple berry syrup, lime juice, tequila, & is then garnished with strawberries, blackberries, and blueberries). Ditus also likes cranberry grape soda & shirley temples (a non alcoholic drink made with grenadine, ginger ale, lemon-lime soda, & garnished with maraschino cherries).

They have a very successful up-and-coming fashion brand called andro-cene. Ditus started it after receiving loans from Aphrodite & Ganymede. It's style and accessories are very androgynous, appealing to gender non-conforming people. It's slowly been gaining traction, with a planned first ever fashion show coming up. For other work they also model for/endorses Bow + Arrow, Kaleidoscope Lab, Maison du Drame, La Petit Amour (cosmetics) & Graces' Glam. Ditus is also a co-chair of the All Love Festival, along with Ganymede. He's also a contributing writer for Kythereia magazine, Glamgerous, and Ganymede's LGBTQ+ magazine- The Rainbow Room. They've even been a guest co-host for Philotes' podcast Between the Sheets.

Ditus' go-to treat are mochi ice cream sandwiches! He also likes ambrosia salad (a dessert made with fruity mini marshmallows, maraschino cherries, whipping cream, shredded coconut, Greek vanilla yogurt, powdered sugar, pineapple tidbits, & mandarin orange slices), and vanilla cheesecake from Hollyhock’s Bakery.

They have been declared "winner" at the Olympian Gala for the best outfit, where they went far & beyond for the "A Night at the Opera" theme a few years ago- complete with a diamond studded Venetian style mask.

They don't like bringing attention to their romantic relationships. He feels conflicted about an intense & instant experience he had with a naiad nymph named Salmacis. Despite both of them agreeing to keep their distance, they always seem to find their way back together. They somewhat keep in touch through Fatestagram and O-mail.

Ditus' favorite meals include yakitori (drizzled in tzatziki & tare sauces), unadon, and kamo nandan.

In their free time, they do like it when things are chilled- when they work on their sculptures, swimming, listen to music, do pottery, painting (mainly portraits & abstract art), experimenting with make-up (is a huge fan of the La Petit Amour shimmering lip glass in Kissable Kiwi), cloud surfing, reading, & writing. Ditus also doesn't mind turning up & going out, visiting the hottest nightclubs like The Void, Dove, Neon Palace, and Sunspot.

"How other people view you doesn't matter. It's how you see yourself."

[skate-tautoloandsym]

Jupiter (a bit cut off) and 🌙 moons Io, Europa and Ganymede. Callisto was in my view but catching all moons 🌝 with my smartphone camera 📸 was hard. I used skyandtelescope.org (Jupiter’s moons) for identification, thanks a lot. Photograph 11 : 38 PM, Sept. 19, 2022.

木星と木星の月(イオ(Io)、エウロパ(Europa), ガニメデ (Ganymede))。カリストは目に見えた。写真に見えない。

Jupiter (above). 木星。

[gabbyzvolt25]

Me when my friends say they can’t do something:

[andromeda1023]

July 2020 is probably the best month for astronomy enthusiasts. It started with a penumbral lunar eclipse on July 5. Now there are three eye-catching celestial events ahead: the opposition of Jupiter, the opposition of Saturn, and a double meteor shower. Let’s talk about the opposition of Jupiter.

In celestial mechanics, a planetary opposition occurs when the Earth lies between the Sun and the planet with Earth being on the same side of the planet as shown below.

Thus on July 14, the Sun, the Earth, and Jupiter will lie along a straight line with Earth at the center. This optimal positioning occurs when Jupiter is almost directly opposite the Sun in the sky. Since the Sun reaches its greatest distance below the horizon at midnight, the point opposite to it is highest in the sky at the same time.

At around the same time that Jupiter passes opposition, it also makes its closest approach to the Earth – termed its perigee – making it appear at its brightest and largest. However, Jupiter’s orbit lies far out in the solar system, at 5.2 AU from the Sun, and hence the angular size of Jupiter doesn’t vary over the course of conjunction and opposition.

At the opposition, Jupiter will be at a distance of about 619.34 million Km (4.14 AU) from the Earth. This is about 9 million Km closer than the average distance from Earth. Even at its closest approach to the Earth, however, it is not possible to distinguish it as more than a star-like point of light with the naked eye. A telescope can help you spot the four Galilean moons of Jupiter: Ganymede, Io, Europ, and Callisto.

Opposition marks the middle of the best time of year to see a planet. Since Jupiter will be opposite to the Sun, it will rise soon after sunset, reach its highest point in the sky around midnight, and will be out of sight at sunrise. The image below shows the position of Jupiter at 10:00 pm. Jupiter will shine bright at magnitude -2.75 and it will be the brightest object in the night sky after the Moon. The brighter Venus will rise a couple of hours before the Sun. Can you spot Saturn nearby? The ringed planet will make its closest approach a week later, on July 21.

Video and link: https://www.secretsofuniverse.in/opposition-of-jupiter-july-2020/?fbclid=IwAR3d7jIh4gOxsbF-0UR1IGzFGiyAJWMU9GJIKY1tzrLiu0dH2I13cAXTRYo

[taiyokei]

Some break doodles

[superpruchika99world]

Great Conjunction: How you can watch as Jupiter, Saturn align tonight

Science and Environment After a fast paced race to Mars and plans to return to the moon, there is still something left for science and astronomy enthusiasts in 2020, a rare celestial phenomenon —the Great Conjunction.

When Jupiter and Saturn will align to form one of the brightest stars in the night sky on Monday being seperated by just one-tenth of a degree.

ALSO READ: Jupiter and Saturn's great conjunction tonight: Everything you must know

The rare phenomenon can be visible globally including in India between 6:30-7:30 pm. The planets will be easy to see with naked eye by looking toward the southwest just after sunset. Jupiter bigger and closer to Earth will be vastly brighter.

A rare cosmic event- According to Nasa, its was Italian astronomer Galileo Galilei, who shaped the understanding of the solar system by discovering the four moons of Jupiter – Io, Europa, Ganymede, and Callisto in 1610. In that same year, he also discovered a strange oval surrounding Saturn...Read More.

[starwalkapp]

It's a Planet Party! ✨⠀ See Jupiter, Saturn and Pluto with the Moon 🌔 in the night sky 🌌⠀ ⠀ This Friday, the waxing gibbous Moon will pay Jupiter a visit. After dusk, look for Jupiter in the southwestern sky. If you glance at the Moon and Jupiter over several hours, starting at dusk, you will see the moon’s orbit carry it farther from the planet.⠀ ⠀ On a typical night, even a backyard telescope will show you Jupiter’s two main equatorial stripes and its four Galilean moons, named Io, Europa, Callisto, and Ganymede. If you see fewer than four, then some are in front of Jupiter, or hidden behind it.⠀ ⠀ Due to Jupiter’s rapid 10-hour rotation period, the Great Red Spot (or GRS) is only observable from Earth every 2nd or 3rd night, and only during a predictable three-hour window. The GRS will be easiest to see using a medium-sized, or larger, aperture telescope on an evening of good seeing (steady air). If you’d like to see the Great Red Spot in your telescope, it will be crossing the planet after dusk on Friday, and from 10 pm to midnight EDT next Sunday.⠀ ⠀ In the southeastern sky after dusk on Sunday evening, the bright, waxing gibbous Moon will be positioned four finger widths to the right of the bright, yellowish planet Saturn. The pair will cross the sky together for most of the night and will easily appear together within the field of binoculars. To the left of this pair you also can see the bright Pluto. Observers in eastern Indonesia, most of Australia, northern New Zealand, Melanesia, and Polynesia (except Hawaii) will see the Moon occult Saturn on August 12.⠀ ⠀ Yellow-tinted Saturn will remain visible from dusk until about 4 am local time. The ringed planet’s position in the sky is just to the upper left (celestial east) of the stars that form Sagittarius constellation. Saturn is quite a bit dimmer than Jupiter. To find it, look about 3 fist diameters to the lower left (east) of Jupiter. Once the sky is dark, even a small telescope will show Saturn's rings and several of its brighter moons, especially Titan!⠀ ⠀ Check the current position of these planets according to your location in Star Walk 2 app.⠀ ⠀ Text Credit: Chris Vaughan via Instagram https://ift.tt/2YSfE7b

[rabbithaver]

say hello to Phobos, the newest addition to the list of Apparel Projects I Cannot Afford

his dad is Ganymede, and his mom is Dione

also, as an aside: if anyone has any of the Black Currant Plumed apparel they’d be willing to sell to me at a discount, shoot me a PM on FR!

[astrogeoguy]

The Bright Corn Moon Prunes Perseid Meteors, but Saturn Shines while Jupiter Dances and Sports Spots!

(Above: An amazing image of multiple Perseid meteors, the International Space Station, plus aurora on the northern horizon taken by Bill Longo of Toronto in 2015. http://billlongo.com/)

Hello, Summer Stargazers!

Here are your Astronomy Skylights for the week of August 11th, 2019 by Chris Vaughan. Feel free to pass this along to your friends and send me your comments, questions, and suggested topics. I repost these emails with photos at http://astrogeoguy.tumblr.com/ where all the old editions are archived. You can also follow me on Twitter as @astrogeoguy! Unless otherwise noted, all times are Eastern Time. Please click this MailChimp link to subscribe to these emails.

I can bring my Digital Starlab inflatable planetarium to your school or other daytime or evening event. Contact me, and we’ll tour the Universe together!

The Perseids Meteor Shower Peaks!

The prolific Perseids Meteor Shower peaks from Tuesday night until Wednesday morning before dawn. Within a couple of nights before and after the peak date, the quantity of meteors will be reduced somewhat, but still well worth looking up for. Unfortunately, the moon will be extremely full and bright during the peak this year, so the dimmer meteors will be hidden by the moon-lit sky. Thankfully, Perseids are often very long and bright!

(Above: This brief animated clip of the Perseids Meteor shower was produced by Till Credner. NASA APOD for Sept 8, 2018) 

Meteor showers are annual events that occur when the Earth’s orbit passes through zones of debris left by multiple passes of periodic comets. (The analogy would be the material tossed out of a dump truck as it rattles along. The roadway gets pretty dirty if the truck drives the route a number of times!) Over centuries, or longer, the dust-sized and sand-sized (or larger) particles accumulate and spread out a bit. When the Earth encounters them, the particles are caught by our gravity and burn up as they fall through our atmosphere at speeds on the order of 200,000 km/hr. The grains moving that fast through the air generate heat that ionizes the air – producing the long glowing trails we see. The duration of a meteor shower depends on the width of the zone, and the intensity depends on whether we pass through the densest portion, or merely skirt the edges. 

The nickname for meteors is “shooting stars” or “falling stars”, but they bear no physical connection to the distant stars, and all your favourite constellations will look the same as ever at the end of the shower! 

The source of the Perseids material is thought to be 133-year-period Comet 109P/Swift-Tuttle. The active period for this shower is July 13 through August 26, so keep an eye out for them beyond this week. This shower is known for producing 60-80 meteors per hour at the peak - many manifesting as bright, sputtering fireballs! 

While visible anywhere in the night sky, meteors will appear to radiate from a location in the sky (called the radiant) between the constellations of Camelopardalis (the Giraffe) and Perseus (the Hero), which gives this shower its name. The radiant is low in the northeastern sky during mid-August evenings – and nearly overhead by dawn. Meteor showers are best observed in the dark skies before dawn, because that’s the time when the sky overhead is plowing directly into the oncoming debris field, like bugs splatting on a moving car's windshield. When the radiant constellation is overhead, the entire sky down to the horizon is available for meteors. 

The highest Perseid meteor rates this year are expected to occur on from Tuesday night into Wednesday morning August 12-13, when the Earth will be closest to the orbit of comet 109P/Swift-Tuttle and densest part of its debris trail. If you begin to watch after dark on Tuesday evening, you might catch very long meteors that are skimming the Earth’s upper atmosphere. These are fewer, but spectacular. As the night rolls on, the radiant of the meteors will rise higher in the sky, revealing more meteors because they are no longer hidden by the bulk of Earth. The absolute best time to view is around 4 am local time when the radiant will be almost overhead.

(Above: The radiant for the annual Perseids Meteor Shower is in northern Perseus, shown here at 1 am local time this week. But don’t watch for meteors there - any appearing in that area will be the shortest because they are heading directly towards you!) 

For best results, try to find a safe viewing location with as much open sky as possible. If you can hide the moon behind a building or tree, that will help. You can start watching as soon as it is dark - to catch very long meteors produced by particles skimming the Earth’s upper atmosphere. These are rarer, but leave very long streaks. Don’t worry about watching the radiant. Meteors from that position will be heading directly towards you and have very short trails. 

Bring a blanket for warmth and a chaise to avoid neck strain, plus snacks and drinks. Try to keep watching the sky even when chatting with friends or family – they’ll understand. Call out when you see one; a bit of friendly competition is fun! 

Don’t look at your phone or tablet – the bright screen will spoil your dark adaptation. If you can, minimize the brightness or cover the screen with red film. Disabling app notifications will reduce the chances of unexpected bright light, too. And remember that binoculars and telescopes will not help you see meteors because they have fields of view that are too narrow. I’ll post some diagrams here. Good hunting! 

The Moon and Planets

This week, the moon will reach its full phase and illuminate the night sky worldwide – to the disappointment of Perseid Meteor Shower viewers. Then the moon will commence its two-week swing back towards the sun. In the meantime, the moon will visit Saturn, and Jupiter will sport spots on Monday and Saturday. Here are your Skylights for this week! 

In the southeastern sky after dusk tonight (Sunday), look for the waxing gibbous moon positioned just four finger widths to the right (celestial west) of the bright, yellowish planet Saturn. The pretty duo will cross the sky together for most of the night and will easily appear together within the field of binoculars. If you watch the pair over several hours, starting at dusk, you will see the moon’s orbit carry it closer to the planet while the rotation of the sky lifts Saturn higher than the moon. Observers in eastern Indonesia, most of Australia, northern New Zealand, Melanesia, and Polynesia (except Hawaii) will see the moon occult Saturn on August 12. 

(Above: As shown here at 9:30 pm local time, on sunday evening, August 11, the waxing gibbous moon will sit above the Teapot-shaped constellation of Sagittarius, and close to yellowish Saturn. Very bright Jupiter will be about three fist diameters to their right. Note where Saturn is so you can find it again after the moon hops away.) 

The August full moon, known as the “Sturgeon Moon”, “Red Moon”, “Green Corn Moon”, and “Grain Moon”, always shines among or near the stars of Aquarius (the Water-Bearer) or Capricornus (the Sea-Goat). Full moons always rise at sunset and set at sunrise. Since this full moon phase will occur in the morning daylight hours of Thursday, the moon will appear to be full on both Wednesday and Thursday evening in the Americas. When full, sunlight is hitting the moon vertically and casting no shadows. All of the variations in brightness we see are generated by differences in the reflectivity, or albedo, of the lunar surface rocks. 

On nights around the full moon phase, bright ray features may be seen radiating from the younger craters on the lunar near side. A particularly interesting example of this is the ray system for the crater Proclus. The 28 km wide crater and its ray system are visible in binoculars. They are located at the lower left edge of Mare Crisium, the round, grey basin near the moon’s upper right edge (northeast on the moon). The Proclus rays, about 600 km in length, only appear on the eastern, right-hand side of the crater, and within Mare Crisium, suggesting that the impactor that made them arrived at a shallow angle from the southwest. (Note that east and west are reversed on the moon). 

The still-very-bright moon will end the week below the stars of western Pisces (the Fishes), but it won’t rise until late evening and then linger into the morning daytime sky. 

Aside from the moon, Jupiter will be the brightest object in the night-time sky this week. As the sky begins to darken, look for the giant planet sitting less than halfway up the southwestern sky. As the evening passes, Jupiter will sink lower, setting in the west just before 1:30 am local time. On Sunday, August 11, Jupiter will end a westerly retrograde loop that began in April, and resume its regular eastward motion with respect to the stars of southern Ophiuchus (the Serpent-Bearer). 

The difference in orbital speed between a given planet and Earth generates these predictable, temporary reversals in motion that astronomers call retrograde loops. During Jupiter’s retrograde period, Earth was passing Jupiter “on the inside track” of the Solar System’s “racetrack” around the sun. The stars, which are far beyond the planets, are fixed in place, allowing us to see the planets move among them. The word planet comes from a Greek word for “wanderer”. Take note of Jupiter’s position with respect to the bright, reddish star Antares, which is sitting about a palm’s width to Jupiter’s lower right this summer. If you check back every week or two, Jupiter’s orbital motion will be apparent. 

On a typical night, even a backyard telescope will show you Jupiter’s two main equatorial stripes and its four Galilean moons - Io, Europa, Callisto, and Ganymede looking like small white dots arranged in a rough line flanking the planet. If you see fewer than four dots, then some of them are in front of Jupiter, or hidden behind it. Good binoculars will show the moons, too! 

From time to time, the small, round, black shadows cast onto Jupiter’s surface by those four Galilean moons become visible in amateur telescopes as they cross (or transit) Jupiter’s disk. On Monday evening from 9:07 to 11:20 pm EDT, observers in the Americas can watch Io’s small shadow transit Jupiter. On Saturday evening from 8:53 to 11:25 pm EDT, observers in the Americas can watch Europa’s shadow transit the northern hemisphere of Jupiter.

(Above: On Monday evening between 9:07 and 11:20 pm EDT, Io’s small, black shadow will cross the disk of Jupiter as shown here at 9:30 pm EDT.)

Due to Jupiter’s rapid 10-hour rotation period, the Great Red Spot (or GRS) is only observable from Earth every 2nd or 3rd night, and only during a predictable three-hour window. The GRS will be easiest to see using a medium-sized, or larger, aperture telescope on an evening of good seeing (steady air). If you’d like to see the Great Red Spot in your telescope, it will be crossing the planet tonight (Sunday evening) from 9:30 pm to 12:30 am EDT, on Tuesday night after 11:30 pm EDT, after dusk on Wednesday and Friday, and after 10:30 pm EDT next Sunday. 

Yellow-tinted Saturn is prominent this summer, too - but its less bright than Jupiter. The ringed planet will be visible from dusk until about 3:30 am local time. Saturn’s position in the sky is just to the upper left (celestial east) of the stars that form the teapot-shaped constellation of Sagittarius (the Archer). To find Saturn, look about 3 fist diameters to the left (east) of Jupiter. 

Dust off your telescope! Once the sky is dark, even a small telescope will show Saturn's rings and several of its brighter moons, especially Titan! Because Saturn’s axis of rotation is tipped about 27° from vertical (a bit more than Earth’s axis), we can see the top surface of its rings, and its moons can arrange themselves above, below, or to either side of the planet. During this week, Titan will migrate counter-clockwise around Saturn, moving from the right of Saturn tonight (Sunday) to the left of the planet next Sunday. (Remember that your telescope will flip the view around.) 

(Above: The ice giant planets Uranus and Neptune are visible overnight this week, as shown here for midnight local time. The main belt asteroid designated (15) Eunomia, which is at peak brightness for 2019, is at upper right, in Aquarius.)

Tiny, blue Neptune is low in the southeastern sky in late evening, among the stars of Aquarius (the Water-Bearer). The planet will be rising shortly before 9:30 pm local time this week. You’ll find the magnitude 7.8 Neptune sitting half a finger’s width to the left (east) of a medium-bright star named Phi (φ) Aquarii, so both objects will appear together in the field of view of a telescope. The planet is actually moving slowly toward that star and will “kiss” it in early September. 

Blue-green Uranus will be rising just after 11 pm local time this week. It is sitting below the stars of Aries (the Ram) and is just a palm’s width above the head of Cetus (the Whale). At magnitude 5.8, Uranus is bright enough to see in binoculars under dark skies, but not this week. 

This week, Mercury is in the northeastern pre-dawn sky - below the stars of Gemini (the Twins). After swinging widely away from the sun last week, it will now be descending again. Your best opportunity to see it will land between 5:15 and 5:45 am local time.

(Above: Mercury is at peak visibility in the northeastern sky this week, as shown here at 5:30 am local time on Monday morning.) 

Venus and Mars are lost in the sun’s glare for the next while.  

Aquila the Eagle

If you missed last week’s information about the constellation of Aquila (the Eagle), I posted it here. 

Public Astro-Themed Events

Every Monday evening, York University’s Allan I. Carswell Observatory runs an online star party - broadcasting views from four telescopes/cameras, answering viewer questions, and taking requests! Details are here. On Wednesday nights they offer free public viewing through their rooftop telescopes. If it’s cloudy, the astronomers give tours and presentations. Details are here. 

On Wednesday, August 14, starting at 11 am, U of T’s AstroTour planetarium show will be a Kids Summer Break Show. Find tickets and details here. 

At 7:30 pm on Wednesday, August 14, the RASC Toronto Centre will hold their free monthly Recreational Astronomy Night Meeting at the Ontario Science Centre, and the public are welcome. Talks include The Sky This Month and funtastic stories of the night sky for public outreach. These meetings are also streamed live on RASC-TC’s YouTube channel. Check here for details. Parking is free. 

On Saturday and Sunday, August 17-18, the Ontario Science Centre will present Rockets, Robots & Rovers, exhibits and activities highlighting planetary exploration. Free with admission to the OSC. Details are here. 

The next RASC-hosted Night at the David Dunlap Observatory will be on Saturday, August 17. There will be sky tours in the Skylab planetarium room, space crafts, a tour of the giant 74” telescope, and viewing through lawn telescopes (weather permitting). The doors will open at 8:30 pm for a 9 pm start. Attendance is by tickets only, available here. If you are a RASC Toronto Centre member and wish to help us at DDO in the future, please fill out the volunteer form here. And to join RASC Toronto Centre, visit this page.

Keep looking up, and enjoy the sky when you do. I love questions and requests - so, send me some!