Cosmic Quiver: Saturn’s Vibrations Create Spirals in Rings
(Phys.org) —Astronomers know that gravity from Saturn’s various moons tug at the planet’s rings and make spirals in them. But the catalyst for certain spiral patterns has been difficult to pin down. Now, two Cornell astronomers have determined the source: Saturn itself.
The entire planet can vibrate like a bell within periods of a few hours, and these oscillations cause gravitational tugs that, in turn, create the spiral patterns in the rings. The cause of the vibrations remains unknown.
Astronomers have discovered the largest known structure in the universe, a clump of active galactic cores that stretch 4 billion light-years from end to end. The structure is a light quasar group (LQG), a collection of extremely luminous Galactic Nulcei powered by supermassive central black holes.
So that’s cool and everything, but maybe some of you would be interested to know why this is a significant find? Beyond just its record-setting bigness.
Since Einstein, physicists have accepted something called the Cosmological Principle, which states that the universe looks the same everywhere if you view it on a large enough scale. You might find some weird shit over here, and some other freaky shit over there, but if you pull back the camera far enough, you’ll find that same weird and/or freaky shit cropping up over and over again in a fairly regular distribution. This is because the universe is (probably) infinite in size and (we are pretty darn sure) has, and has always had, the same forces acting on it everywhere.
So why is this new LQG so radical? (It stands for ‘Large Quasar Group,’ btw, not ‘Light Quasar Group.’)
Well, let’s try to comprehend the scale we’re dealing with. A ‘megaparsec,’ written Mpc, is about 3.2 million light years long. The Milky Way is about 0.03 Mpc across (or 100,000 light years). The distance between our galaxy and Andromeda, our closest galactic neighbor, is 0.75 Mpc, or 2.5 million light years. LQGs are usually about 200 Mpc across. Assuming a logarithmic distribution of weird shit outliers (if you don’t know how logarithmic distribution curves work, don’t worry about it), cosmologists predicted that nothing in the universe should be more than 370 Mpc across.
This new LQG is 1200 Mpc long. That’s four billion light years. Four BILLION LIGHT YEARS. Just to travel from one side to the other of this one thing. I mean for fuck’s sake, the universe is only about 14 billion years old! How many of these things could there be?
Right now it looks like the Cosmological Principle might be out the window, unless physicists can find some way to make the existence of this new LQG work with the math (and boy, are they trying). And that’s totally baffling. It would mean—well, we don’t have any idea what it would mean. That the universe isn’t essentially uniform? That some ‘special’ physics apply/applied in some places but not in others? That Something Happened that is totally outside our current ability to understand or quantify stuff happening?
By the way, no one lives there. The radiation from so many quasars would sterilize rock.
To put this into perspective, the Earth is ~4.5 billion years old. The amount of time it would take to cross this LQG traveling at the speed of light (300000000 meters/second) would take almost as long as the entirety of earth’s existence.
Dwarf Galaxy Caught Ramming Into a Large Spiral Galaxy
Observations with NASA’s Chandra X-ray Observatory have revealed a massive cloud of multimillion-degree gas in a galaxy about 60 million light years from Earth. The hot gas cloud is likely caused by a collision between a dwarf galaxy and a much larger galaxy called NGC 1232. If confirmed, this discovery would mark the first time such a collision has been detected only in X-rays, and could have implications for understanding how galaxies grow through similar collisions.
Looking in the mirror from 898,410,414 miles away…
From out there, we look like stars.
Just a tip, NASA: We’re gonna have to give it a better name than “N00213959.jpg”. Maybe “Pale Blue Sparkle”?
(hi-res at NASA website, a more processed version is sure to come… stay tuned)
Oh hey, not a big deal, but the hubble took a picture of a star that’s nearing supernova status
WOAH LOOK AT THAT BEAUTY
VLT peers into a distant nebula
Astronomers using data from ESO’s Very Large Telescope (VLT), at the Paranal Observatory in Chile, have made an impressive composite of the nebula Messier 17, also known as the Omega Nebula or the Swan Nebula. The painting-like image shows vast clouds of gas and dust illuminated by the intense radiation from young stars.
The image shows a central region about 15 light-years across, although the entire nebula is even larger, about 40 light-years in total. Messier 17 is in the constellation of Sagittarius, about 6000 light-years from Earth. It is a popular target for amateur astronomers, who can obtain good quality images using small telescopes.
These deep VLT observations were made at near-infrared wavelengths. In the centre of the image is a cluster of massive young stars whose intense radiation makes the surrounding hydrogen gas glow. To the lower right of the cluster is a huge cloud of molecular gas.
At visible wavelengths, dust grains in the cloud obscure our view, but by observing in infrared light, the glow of the hydrogen gas behind the cloud can be seen shining faintly through. Hidden in this region, which has a dark reddish appearance, the astronomers found the opaque silhouette of a disc of gas and dust.
Although it is small in this image, the disc has a diameter of about 20 000 AU, dwarfing our Solar System. It is thought that this disc is rotating and feeding material onto a central protostar — an early stage in the formation of a new star.
• Image Credit: ESO