I am gonna be a bit sad this week knowing that Cassini will plunge to its death on Friday. What a 20 year voyage it has been!!! We have learned so much from Cassini-Huygens. I can still remember being in tears when I first watched the Huygens probe land on Titan. Thank you, Cassini-Huygens for all you've done!!!

 

Ever wonder what it might be like to approach Saturn in a spaceship??? You don't have to just imagine -- the Cassini spacecraft did just this in 2004, recording thousands of images along the way, and hundreds of thousands more since entering orbit. Some of Cassini's early images have been digitally tweaked, cropped, and compiled into the featured inspiring video which is part of a larger developing IMAX movie project named In Saturn's Rings. In the concluding sequence, Saturn looms increasingly large on approach as cloudy Titan swoops below. With Saturn whirling around in the background, Cassini is next depicted flying over Mimas, with large Herschel Crater clearly visible. Saturn's majestic rings then take over the show as Cassini crosses Saturn's thin ring plane. Dark shadows of the ring appear on Saturn itself. Finally, the enigmatic ice-geyser moon Enceladus appears in the distance and then is approached just as the video clip ends. Enjoy!!!

 

 

 

More on Cassini's "Grand Finale"(9/ 15/ 17) later...

Monday, September 11

Although Neptune appeared at its best at opposition seven days ago, its visibility hardly suffers this week. The outermost major planet lies low in the southeast as darkness falls and climbs highest in the south around midnight local daylight time. Neptune glows at magnitude 7.8, which is bright enough to spot through binoculars if you know where to look. The trick is to find the 4th-magnitude star Lambda (l) Aquarii, which lies about 10° southeast of Aquarius’ distinctive Water Jar asterism. This week, Neptune appears 1.0° east of this star. When viewed through a telescope, Neptune shows a blue-gray disk measuring 2.4" across.

 

Tuesday, September 12

Mercury makes an impressive appearance before dawn in mid-September. It reaches greatest elongation this morning, when it lies 18° west of the Sun and appears 11° high in the east 30 minutes before sunrise. The innermost planet shines at magnitude –0.4 and is the most conspicuous celestial object near the eastern horizon. If you scan this region with binoculars, you’ll also see the 1st-magnitude star Regulus some 2° above Mercury and the ruddy glow of Mars 3° to Mercury’s lower left.

 

Wednesday, September 13

 

Last Quarter Moon arrives at 2:25 a.m. EDT. It rose in the east-northeast late yesterday evening (shortly before midnight) and climbs high in the east before dawn. During this period, our half-lit satellite lies among the background stars of eastern Taurus the Bull.

 

The Moon reaches perigee, the closest point in its orbit around Earth, at 12:06 p.m. EDT. It then lies 229,820 miles (369,860 kilometers) from Earth’s center.

 

Thursday, September 14

Any clear evening during the first half of this week is a good time to explore the constellation Sagittarius the Archer. This star group lies due south and at peak altitude around 8:30 p.m. local daylight time, near the time twilight ends. The brightest stars within the constellation form a distinctive asterism in the shape of a teapot. The central regions of the Milky Way pass through Sagittarius, so it’s always worth exploring the region through binoculars or a telescope.

 

Friday, September 15

Although Saturn reached opposition three months ago today, it remains a tempting target in the evening sky. The ringed world stands some 25° high in the south-southwest as twilight fades to darkness and doesn’t dip below the horizon until close to midnight local daylight time. Saturn shines at magnitude 0.5 against the backdrop of southern Ophiuchus, a constellation whose brightest star glows six times fainter than the planet. When viewed through a telescope, Saturn’s globe measures 17" across while its spectacular ring system spans 38" and tilts 27° to our line of sight. As you gaze upon Saturn from afar this evening, it’s the first time in more than 13 years that the Cassini spacecraft is not observing the ringed planet from up close. The robotic probe burned up in the gas giant’s atmosphere earlier today.

 

Saturday, September 16

Mercury and Mars have appeared near each other in the predawn twilight all week, but they make their closest approach this morning. For North American observers, they slide just 0.25° (half the Full Moon’s diameter) apart and lie in the same low-power field through a telescope. (Mercury spans 6.4" and is about two-thirds lit; Mars is 3.6" across and full.)

 

Sunday, September 17

The waning crescent Moon points toward three planets and a star this morning. The slim crescent stands 6° above Venus with Leo the Lion’s luminary, magnitude 1.4 Regulus, 3° below the planet. Mars and Mercury huddle 11° below Venus.

 

This evening provides a nice opportunity to see Saturn’s seven brightest moons through a telescope. The toughest to spot normally are the two inner ones — Mimas and Enceladus — which never stray far from the rings’ glare. But tonight, the two satellites reach greatest western elongation within two hours of each other. Tethys, Dione, Rhea, and Titan show up more clearly because they glow brighter and lie farther from the planet. Distant Iapetus rounds out Saturn’s “magnificent seven” satellites on display. If you draw a line from Saturn to 8th-magnitude Titan and extend it an equal distance, 11th-magnitude Iapetus will be right there.

A Farewell Kiss...

 

BGP friends, about two hours ago, Cassini did one last flyby of Titan, passing within 73,974 miles of the moon's surface , giving Titan a "goodbye kiss" and using Titan's gravity to force itself into a final descent, which will begin in about nine hours. With Titan's help, Cassini is now on a suicide mission from which there is no turning back. The "Grand Finale will culminate Friday morning when the spacecraft enters Saturn's atmosphere at 6:31 A.M. At 6:32 , Cassini's antennas will point away from the earth, resulting in a loss of signal. Then, in the high pressure and temperature of the Jovian ringed world, Cassini will melt and become one with the planet. And I will probably shed some more tears.

An overview of Cassini's "Grand Finale" :

 

I love this galaxy.

Also known as M104 and NGC4594, the Sombrero galaxy resides in the Virgo constellation and is about 30 million LY from our very own pale blue dot. The Sombrero galaxy is about 50,000 LY across and is thought to house a large black hole at the center, just like the Milky Way.

 

Mamaw, TB&G , Owl ..... I hope I haven't lost you folks. I love hearing from all of you astronomy buffs on here. Let me know if there is a topic in astronomy that want me to talk more about. Exoplanets, deep-space objects, cosmology , black holes... whatever you are interested in just let me know. Feel free to post your own thoughts on any aspect of astronomy. I enjoy thinking and learning about our magnificent universe through an exchange of ideas. This thread is your home to post your thoughts.

Better watch your moon when circling Uranus...

 

How precarious is it to be a moon circling Uranus? (Insert your own joke, if you want) Actually, it's a pretty dangerous place for a moon to be. Discovered in 1781 by William Herschel with a telescope he built himself, Uranus is a big icy giant of a planet, orbiting the Sun once every 84 of our years. In addition to being marked by a system of faint , thin rings, Uranus has 27 moons( a lot, but still less than Jupiter's 67 and Saturn's 62).

 

Why the danger? Well, new measurements indicate at least two likely collisions between four of Uranus' moons millions of years from now. One of Uranus' rings(the Eta ring) is triangular, rather than circular . The reason for this distortion in the ring's shape--- the tiny moon, Cressida--- only 51 miles across. Scientists were able to use the distortion in the Eta ring to measure Cressida's mass and density which, in turn, allowed for the determination of the gravitational interactions between Cressida and other nearby moons. The conclusion: There will be a collision between Cressida and another moon, most likely Desdemona. The collision is imminent, which in astronomical terms, means sometime between tonight and a million years from tonight. Cressida and Desdemona orbit the giant icy Uranus only 560 miles apart.

 

Not only are Cressida and Desdemona destined for doom , two other moons, Belinda and Cupid , are also likely headed for a cosmological big banging between 10 million and 1 billion years from now. In light of the fact that two diffuse rings around the planet today likely formed from the debris of previous collisions between now-long-gone moons, it seems that these future moon collisions are inevitable.

 

Interestingly enough, the future collisions between Cressida and Desdemona and Belinda and Cupid may not completely destroy these moons but just break them into pieces. Who knows , a few million years from now Uranus may actually add to its list of moons.

 

Btw, I love some of the names of Uranus' moons. Of course, we have the four mentioned above that are gonna collide. Plus, the moon I mentioned a few months back , Miranda , is one of my favorites moons in our solar system. The other moons of Uranus --- Titania , Umbriel, Ariel , Cordelia, Ophelia, Portia, Trinculo, Oberon, Bianca , Juliet , Caliban, Prospero , Francisco, Rosalind, Sycorax, Setebos, Perdita, Ferdinand, Stephano, and Mab.

 

Oh yeah, two more .... Margaret and Puck ! Gotta love Puck .

Edited September 12, 20179 yr by Science Friction

BGP'ers, how did it feel to watch our Sun disappear on that special day last month? I was left shaking, in awe, and in tears. Many of you who experienced totality were probably surprised, and maybe a little shocked, at how you were affected by this event. For me, it was very much a spiritual experience. For those expecting just a brief moment of dusk, the spectacle of unusually rapid darkness, breathtakingly bright glowing beads around the Moon's edge, shockingly pink solar prominences, and a strangely detailed corona stretching across the sky, caught many by surprise and left thousands across the country breathless.

 

I think you will enjoy the short video below which captures the eclipse from Oregon with equipment designed to track a close-up of the sun's periphery. As the video ends, you will watch the Sun being reborn on the other side of the Moon from where it departed. We are blessed to live in such an incredible universe !!! Enjoy.

 

[video=youtube;5D9j-8Vhyto]

For those who are gonna be around your TV sets tonight at 9, let me encourage you to check out Nova on KET . The show tonight is called "Death Dive to Saturn." The episode deals with Cassini's rendezvous with Saturn on Friday morning, when it will end its 20-year mission by vaporizing in Saturn's atmosphere. Let me know what you think of the show.

Want to chase another total eclipse? One great vantage point would be the Atacama Desert in Chile. The path of totality will include the southern Atacama desert in Chile's Elqui Valley. Just to whet your appetite a bit, here's an image you will enjoy.

 

Sometimes, the sky mimics the ground. Taken in May of 2017 from the Atacama Desert in Chile, the foreground of the image encompasses the dipping edge of the caldera of an extinct volcano. Poetically echoing the dip below is the arch of our Milky Way Galaxy above. Many famous icons dot this southern nighttime vista, including the center of our Milky Way Galaxy on the far left, the bright orange star Antares also on the left, the constellation of the Southern Cross near the top of the arch, and the red-glowing Gum Nebula on the far right. Just above the horizon and splitting two distant volcanic peaks near the image center is the Large Magellanic Cloud -- the largest satellite galaxy of the Milky Way. Enjoy!!!

 

Btw, the total eclipse that I was referring to in the above post is the one on July 2, 2019. The path of the eclipse starts in the Pacific Ocean well east of New Zealand, and crosses the ocean north of the Pitcairn Islands, over the Tubai and Tuamotu islands, before making landfall over Chile and Argentina, with sunset south of Buenos Aires. The path of totality is 200 km wide at its maximum, and the maximum duration is 4 minutes and 32 seconds in the mid Pacific Ocean.

For those who are gonna be around your TV sets tonight at 9, let me encourage you to check out Nova on KET . The show tonight is called "Death Dive to Saturn." The episode deals with Cassini's rendezvous with Saturn on Friday morning, when it will end its 20-year mission by vaporizing in Saturn's atmosphere. Let me know what you think of the show.

 

Really dug the program.

 

Did not realize that Saturn had so many moons.

 

It was intriguing to see the images of Titan, and though I didn't completely understand it nor can I express it much in scientific terms, the points regarding the discovery of the propellors within the rings of Saturn were interesting, and I hope to eventually understand them better as the program seemed to be saying that they held answers to many questions regarding the development of planets.

 

If you @Science Friction can expand on that, and I've no doubt that you can, I'd love to get a better understanding of just what they were saying.

 

While I'm at it, I'd like to say that though I don't always completely understand what you're talking about, or can remember all the details, I very much appreciate the efforts you take in teaching us this stuff in such detail.

 

It really blows my mind all of the stuff that you have in yours, and I am in awe of how you can possibly retain all of that. Obviously interest and passion lead to learning which lead to retaining, but still dude, that's a ton of intricate stuff to remember, and I applaud you for your ability to do so.

For those who are gonna be around your TV sets tonight at 9, let me encourage you to check out Nova on KET . The show tonight is called "Death Dive to Saturn." The episode deals with Cassini's rendezvous with Saturn on Friday morning, when it will end its 20-year mission by vaporizing in Saturn's atmosphere. Let me know what you think of the show.

 

Another thing that they talked about that I found interesting, as I never previously considered it, is how Cassini was still being managed by older computing systems. It stands to reason as it was launched 20 years ago. In the program just before they mentioned it they were showing old monitors etc... and while I was thinking what's with all of the old equipment, they then proceeded to say so.

One of my BGP friends asked me to talk about the September 23rd alignment that has the doomsday prophets clamoring about Armageddon. Don't worry, every couple of years, the "end of the world" crowd uses what limited knowledge they have of astronomy to try to scare folks into believing that we are about to see the fulfillment of some Biblical prophecy. It's always a bunch of bunk. There are some fear-mongers who actually enjoy spreading their false "gospel" that some astronomical occurrence or alignment is proof of some revelation in the Biblical text.

 

Fast forward to next Saturday , September 23 . This date is the next in a long series of doomsdays predicted by the religious alarmists. When one doomsday comes and goes, they excuse it away and come up with another one a couple of years later. It has happened for hundreds, if not thousands, of years. Hale-Bopp was promoted by some as a harbinger of doom. Haley's Comet has been promoted as a doomsday comet throughout the centuries. People have even committed suicide thinking Haley's was about to bring God's wrath upon planet Earth.

 

I know this is a bit of a tease, but fast forward to next Saturday, September 23. There is going to be a celestial alignment that I will soon talk about which has the doomday prophets clamoring that a couple of verses in Revelation forecasts.

 

So, will the sky on the 23rd mirror the "signs" predicted in the book of Revelation? Does this suggests that the end is near? Stay tuned to this space...