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Post by MartinT on Oct 4, 2018 7:34:57 GMT
Gosh, that puts an end to a comet being a fiery blob!
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Post by Eduardo Wobblechops on Oct 5, 2018 10:33:31 GMT
Looks like the Himalayas, or even the Cairngorms in winter.
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Post by rfan8312 on Oct 7, 2018 4:35:19 GMT
Yes, interesting! A free-roaming planet not orbiting a star. But going back to earlier this year, there was a discovery of planets in a galaxy far far away some 3.8 Billion light years away using gravitational lensing techniques. A very lucky and rare alignment of two galaxies at different distances. One jaw dropping conclusion from the observations was "Furthermore, the scientists said results suggest that in most galaxies, there are about 2,000 free-floating planets for every star. " I mean ... what?! ... wow! www.scientificamerican.com/article/did-we-just-find-exoplanets-in-another-galaxy/The universe just gets crazier the more we learn about it. Very interesting. I wonder though will a free floating planet maintain its sphere shape? I believed a planet's shape is due in part to its revolution and to its orbit of a star. Are these things revolving while floating freely through space? |
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Post by jandl100 on Oct 7, 2018 9:04:45 GMT
Yes, interesting! A free-roaming planet not orbiting a star. But going back to earlier this year, there was a discovery of planets in a galaxy far far away some 3.8 Billion light years away using gravitational lensing techniques. A very lucky and rare alignment of two galaxies at different distances. One jaw dropping conclusion from the observations was "Furthermore, the scientists said results suggest that in most galaxies, there are about 2,000 free-floating planets for every star. " I mean ... what?! ... wow! www.scientificamerican.com/article/did-we-just-find-exoplanets-in-another-galaxy/The universe just gets crazier the more we learn about it. Very interesting. I wonder though will a free floating planet maintain its sphere shape? I believed a planet's shape is due in part to its revolution and to its orbit of a star. Are these things revolving while floating freely through space? Yes, I think they are bound to be spinning around an axis. But not revolving (orbiting) around anything. But I don't see why that would affect their oblate spheroid shape. A sphere is the natural low-energy state for a gravitationally bound object. An interesting current theory is that most/all planetary systems will expel planets during their earlier, more chaotic periods. The best way to explain the makeup of our own solar system may be for a Neptune-sized planet to have been slung out into the interstellar void by an encounter with Jupiter. There may well be trillions of free roaming planets in the galaxy. blogs.nature.com/news/2012/10/did-the-solar-system-start-with-an-extra-planet.html |
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Post by MartinT on Oct 7, 2018 10:48:44 GMT
Interstellar planets must be exceedingly cold without a star to keep them heated.
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Post by jandl100 on Oct 7, 2018 10:56:10 GMT
Yes, you'd need to wear your longjohns all year * the time.
The planets would rapidly cool after being ejected from their star, the only sustained heat source would be from the natural radioactivity from radioactive elements in their interiors.
I guess a certain proportion would eventually be captured by another star, doubtless creating havoc among any already resident planets!
* it just occurred to me that free roaming planets won't have years!
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Post by MartinT on Oct 7, 2018 12:24:30 GMT
Damned year 1 just won't end!
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Post by zippy on Oct 7, 2018 13:17:57 GMT
..The planets would rapidly cool after being ejected from their star, the only sustained heat source would be from the natural radioactivity from radioactive elements in their interiors. In some cases that would be enough to keep the planet up to a 'liveable' temperature (it's been suggested a 10Km layer of ice would do that) I'm not sure what would be the effect of having virtually no light though. |
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Post by jandl100 on Oct 22, 2018 9:00:37 GMT
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Post by bigman80 on Oct 22, 2018 12:28:13 GMT
Fantastic thread.
We bought a telescope last year and it blew my mind at how much detail we could see on the moon's surface. We then spent a couple of night honing our navigation skills and finally found Mars and Jupiter. We could see the red spot and I was just totally in awe.
It's a really enjoyable past time and something that adds a little humble pie over how insignificant our planet is in the grand scheme of things.
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Post by ChrisB on Oct 22, 2018 13:12:28 GMT
Wow!
Thanks for that Jerry.
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Post by jandl100 on Oct 24, 2018 6:33:39 GMT
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Post by jandl100 on Dec 21, 2018 19:35:38 GMT
"The December 2018 close approach by the large, near-Earth asteroid 2003 SD220 has provided astronomers an outstanding opportunity to obtain detailed radar images of the surface and shape of the object and to improve the understanding of its orbit. The asteroid will fly safely past Earth on Saturday, Dec. 22, at a distance of about 1.8 million miles (2.9 million kilometers). This will be the asteroid's closest approach in more than 400 years and the closest until 2070, when the asteroid will safely approach Earth slightly closer. The radar images reveal an asteroid with a length of at least one mile (1.6 kilometers) and a shape similar to that of the exposed portion of a hippopotamus wading in a river. They were obtained Dec. 15-17 "  www.jpl.nasa.gov/news/news.php?feature=7312&utm_source=iContact&utm_medium=email&utm_campaign=nasajpl&utm_content=daily-20181221-1 |
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Post by MartinT on Dec 21, 2018 21:50:24 GMT
Fantastic imagery at the distances involved.
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Post by jandl100 on Dec 24, 2018 12:39:14 GMT
He's on his way .... passing the orbit of Jupiter atm apparently ....  |
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Post by ChrisB on Dec 24, 2018 12:41:34 GMT
Ha! Looks a bit bumpy out there.
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Post by jandl100 on Dec 24, 2018 12:50:54 GMT
... entering the asteroid belt
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Post by jandl100 on Jan 1, 2019 9:24:27 GMT
It is amazing to think about it, but the New Horizons probe that has now reached the Kuiper Belt asteroid known as Ultima Thule has now started transmitting the photos it took as it passed by.
It is so far away that we won't start receiving them for another 6 hours.
Wow.
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Post by MartinT on Jan 1, 2019 12:29:29 GMT
Space is big. 6 hours at the speed of light, that's 6.5bn km.
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Post by jandl100 on Jan 2, 2019 7:06:08 GMT
First image of Ultima Thule from the New Horizons probe - still a long way off, 100,000s of km. Images now being sent will be of fantastic resolution and will show the object in great detail. For now, we just know that it is shaped somewhat like a peanut!  |
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