This sort of info feeds my febrile brain. This is what I cribbed from The Guardian.
“The most detailed three-dimensional map yet of the Milky Way has been revealed, showing that our galaxy is not a flat disc but has a “warped” shape like a fascinator hat or a vinyl record that has been left in the sun. “The stars 60,000 light years away from the Milky Way’s centre are as far as 4,500 light years above or below the galactic plane – this is a big percentage,” said Dr Dorota Skowron of the University of Warsaw, first author of the latest research.
Both the new study and an earlier one published in February, which found a similar shape, are based on the distribution across the galaxy of stars known as Cepheids – bodies whose brightness varies in a regular cycle over time. This phenomenon of dimming and brightening is the key to creating the maps. While a star might be fainter because it is further away, it could also be because it is less luminous. For Cepheids, the maximum brightness of the star is related to the length of time the cycle of brightening and dimming takes, with brighter Cepheids having longer cycles. By comparing this intrinsic brightness with how bright the star appears to be, researchers can work out how far away a Cepheid is.
The new study, published in the journal Science, encompasses data from more than 2,400 Cepheids, allowing the team to build the most detailed three-dimensional map yet of the Milky Way.
Shape of the Milky Way
As with the previous work, the new study shows the Cepheids disproportionately lie on one side of the warped galaxy, forming an arc-shaped spread.
The Polish team also found younger Cepheids lie nearer the centre of the Milky Way, while older Cepheids are further out. A computer simulation revealed there would need to have been star-forming events 64m, 113m and 175m years ago to produce the distribution of Cepheids seen today.
Going to sleep tonight will be much easier now I’ve learned that!
I saw this in a local newspaper yesterday. Is it true?
Well for starters the posh name is a Lunar Halo.
A lunar halo is caused by the refraction, reflection, and dispersion of light through ice particles suspended within thin, wispy, high altitude cirrus or cirrostratus clouds. As light passes through these hexagon-shaped ice crystals, it is bent at a 22-degree angle, creating a halo 22 degrees in radius (or 44 degrees in diameter). A double halo, sometimes with spokes, may be seen on rare occasions when light reflects off water or ice.
Diagram showing how a Lunar Halo is formed
The prism effect of light passing through these six-sided ice crystals separates the light into its various colors, resulting in a halo tinged with very pale rainbow colours with red on the inside and blue on the outside. The phenomenon of a lunar halo is similar to a rainbow produced by sunlight and rain falling between your eye and the sun.
What does folklore say about a ring around the moon? Folklore says a lunar halo is the precursor of impending unsettled weather, especially during the winter months. This is often proved true, as cirrus and cirrostratus clouds generally precede rain and storm systems. Another version says that if you count the number of stars you can see in the ring that’s the number of days till it rains.
Lunar halos are, apparently, fairly common. So watch the night sky — and keep the umbrella handy!
I’m a space pics freak – I admit it! This Beeb (BBC) item is simply spectacular. Here’s the blurb that goes with the fab pic:
“This beautiful picture of Jupiter was assembled from three separate images acquired by Nasa’s Juno spacecraft as it made another of its close passes of the gas giant. The probe has a colour camera onboard and citizen scientists are encouraged to play with the data to make their own views of the planet. This one, which is colour-enhanced, was produced by Kevin M Gill.
The US space agency has dubbed it “Jupiter Marble” – a reference to the full disc pictures of Earth captured by satellites down the years that have been called “Blue Marble”.
The Jupiter mosaic includes shots taken between 26,900 km and 95,400 km from the planet’s cloud-tops. It gives a great view of southern hemisphere storms and of the famous Great Red Spot. This spectacular anticyclone, which has been in existence for hundreds of years, is gradually having its secrets revealed by the Juno mission. The probe has already established that its roots extend at least 350 km down into the atmosphere. Scientists hope their various investigations will reveal the key mechanisms that drove the spot and keep it from dissipating.
The Juno mission operates a raw image site where amateur processors can get involved.”
Double click on the image to see it in its munificence.
Alas it was cloudy here in Fort Bragg, CA yesterday evening and I only got to see an itsy bitsy bit of the lunar eclipse. This evening I have been having a great old time “thumbing” through photos of the event taken by those who a) have better cameras than I and b) who know how to use them. Here’s my pick of what I have perused [click on any photo to see full size]:
In the weather section of this morning’s Press Democrat was a squib, “It’s a gibbous moon. (It) shows the man in the moon, Can you see it?” That set me going. I found these three pics which will help you find his face the next time you look:
Here’s the same pic minus explanation …..
See if you can see the face
And here is an enhanced photo that shows you exactly what he looks like:
I love piano music. I have five different renditions of Clair de Lune. The one on the following vid is as good as it gets. The piece was published in 1905 as the third of four movements in the composer’s Suite Bergamasque, and unlike the other parts of this work, Clair is quiet, contemplative, and slightly melancholy, evoking the feeling of a solitary walk through a moonlit garden.
The visualization in the vid? “The visuals were composed like a nature documentary, with clean cuts and a mostly stationary virtual camera. The viewer follows the Sun throughout a lunar day, seeing sunrises and then sunsets over prominent features on the Moon. The sprawling ray system surrounding Copernicus crater, for example, is revealed beneath receding shadows at sunrise and later slips back into darkness as night encroaches. The visualization was created to accompany a performance of Clair de Lune by the National Symphony Orchestra Pops, led by conductor Emil de Cou, at the Kennedy Center for the Performing Arts in Washington, DC, on June 1 and 2, 2018, as part of a celebration of NASA’s 60th anniversary. The visualization uses a digital 3D model of the Moon built from Lunar Reconnaissance Orbiter global elevation maps and image mosaics. The lighting is derived from actual Sun angles during lunar days in 2018.”
The vid lasts about 5 mins:
Thanks to wife for the heads up on this one. Thanks NASA for creating the vid,