Astronomy & Space Exploration

Invictus said:
No. It's ~350 million light-years away from Earth, and not hurtling in our direction. But we will be 'swallowed' by Andromeda in ~3.8 billion years (approaching us at 250,000 mph). Galactic collisions aren't that bad anyway. They'll just merge to become a larger galaxy - since it's mostly empty space.



This is what the sky will look like when that happens.

Shame that we won't be around to see it. :(
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Amazing simulation. Hard to believe we would be ok after going through that but I guess it makes sense.
 
Nik70 said:
Amazing simulation. Hard to believe we would be ok after going through that but I guess it makes sense.
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How about another weird factoid?

Humans are 99% empty space too. :nervous:
You could fit the entire human race in the volume of a sugar cube

This is because matter is incredibly, mind-bogglingly empty. An atom is like a miniature Solar System, with a tight nucleus playing the role of a Sun orbited by electrons like planets. But the nucleus is incredibly tiny compared with the orbits of the electrons. Tom Stoppard, the playwright, had the best image. He said, if the nucleus is like the altar of St Paul's cathedral, an electron is like a moth in the cathedral, one moment by the altar, the next by the dome. Imagine squeezing all the space out of an atom. Well, if you did that to all the atoms in all the people in the world, you could indeed fit the entire human race in the volume of a sugar cube.
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http://www.physics.org/featuredetail.asp?id=41

And atoms are 99.99999% empty space.
 
Invictus said:
No. It's ~350 million light-years away from Earth, and not hurtling in our direction. But we will be 'swallowed' by Andromeda in ~3.8 billion years (approaching us at 250,000 mph). Galactic collisions aren't that bad anyway. They'll just merge to become a larger galaxy - since it's mostly empty space.

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Pretty cool. Once they 'touch', how long does the rest of that take?
 
I googled IC 1101. The youtube video i watched says its a dying galaxy and is a billion light years away..

It's probably dead by now.
 
VeevaVee said:
Pretty cool. Once they 'touch', how long does the rest of that take?
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Computer simulations derived from Hubble's data show that it will take an additional two billion years after the encounter for the interacting galaxies to completely merge under the tug of gravity and reshape into a single elliptical galaxy similar to the kind commonly seen in the local universe.
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http://science.nasa.gov/science-news/science-at-nasa/2012/31may_andromeda/

There's a theory that suggests IC 1101 is also an intermediary phase of a galactic collision, and is whipping itself into form - hence the unusually large amount of apparent mass - as observed by us.
 
unchanged_lineup said:
Yeah, let's go there. Or, enjoy the thread.



PEDANTIC CLARIFICATION: The large number of people around the world think we, as debatably-intelligent life, are some unique creature that exists here and here only.
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So "some people" rather than "we" :p
 
Hubble Team Breaks Cosmic Distance Record
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MARCH 3, 2016: NASA's Hubble Space Telescope is an amazing time machine; by looking back through space, astronomers actually look back through time. Now, by pushing Hubble to its limits, an international team of astronomers has shattered the cosmic distance record by viewing the farthest galaxy ever seen. Named GN-z11, this surprisingly bright, infant galaxy is seen as it was 13.4 billion years in the past. The astronomers saw it as it existed just 400 million years after the big bang, when the universe was only three percent of its current age. At a spectroscopically confirmed redshift of 11.1, the galaxy is even farther away than originally thought. It existed only 200 million to 300 million years after the time when scientists believe the very first stars started to form. At a billion solar masses, it is producing stars surprisingly quickly for such an early time. This new record will most likely stand until the launch of Hubble's successor, the James Webb Space Telescope, which will look even deeper into the universe for early galaxies.

http://hubblesite.org/newscenter/archive/releases/2016/07
 
Looking forward to the age of cosmic superheroes protecting the earth
 
Richter scale.
richter_scale_graphic_representation.gif
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Magnitude 1 | Energy released = 1.995262e+6 Joules = 4.768791e-4 tons of TNT.
Magnitude 5 | Energy released = 1.995262e+12 Joules = 4.768791e+2 tons of TNT.
Magnitude 9.5 (1960 Chile earthquake in Valvidia - highest recorded on Earth) | Energy released = 1.122018e+19 Joules = 2.681688e+9 tons of TNT.

***

Magnitude 10 (Entire continental plate cracks or splits in half) | | Energy released = 1.995262e+21 Joules = 4.768791e+11 tons of TNT.
Magnitude 11-12 (Chicxulub level impact that ma) | | Energy released = 1.995262e+21 Joules = 4.768791e+11 tons of TNT = 1 Billion times the energy released in Hiroshima and Nagasaki.



Magnitude 13-14 (Venus size planet collides with Earth) | Energy released = 6.309573e+25 Joules = 1.508024e+16 of TNT.
Magnitude 16 (Planet earth melts completely) | Energy released = 6.309573e+28 Joules = 1.508024e+19 tons of TNT.

***

Magnitude 22:
In December 2004, the magnetar SGR 1806-20 underwent such a starquake. In one-tenth of a second the subsequent blast released something like 2 times 1046 ergs of energy — equal to about 50 trillion times the Sun’s output during that same period. The quake, which occurred 50,000 light years from Earth, released gamma rays equivalent to 1037 kW in intensity.
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Cause of the quake - Realignment of the magnetar's ultra rigid surface lattice by a few micrometers - a process that lasted a few millionths of a second. :lol:

 
The BOSS Supercluster could rewrite cosmological theory

Astronomers just observed the biggest collection of star stuff that we’ve seen so far.

An international team of scientists described a huge wall of galaxies in a little-explored part of the cosmos. It’s over a billion light years long, bristling with 830 galaxies. They have dubbed it the BOSS Great Wall, named after the BOSS survey (Baryon Oscillation Spectroscopic Survey) which spotted it.

At the largest scale, matter in the universe forms long threads and dense clusters—like a net with big knots. Between the threads are voids drained of almost all matter. In 2014, astronomers learned that our Milky Way galaxy is just one of many in the Laniakea supercluster, which is a web of 100,000 galaxies.

But superclusters can stick together and form even bigger structures. The BOSS Great Wall is a tight network of four superclusters. The largest two form a stretched-out wall of galaxies that’s about 1.2 billion light years long. This is one of only a few supercluster systems ever found. Only one other system, the Sloan Great Wall, comes close in size, but not quite close enough—BOSS has over twice as many galaxies and is 170% wider than Sloan.
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“It looks like we have a structure that is bigger than anything else: like two Sloan Great Wall scale structures right next to each other,” said Heidi Lietzen of the Institute of Astrophysics at the University of La Laguna in Spain, who was the lead author of the new study. “The question now is: is it too big for our cosmological theories?”

Scientists are still figuring out what shapes supercluster systems like this one can take, said Elmo Tempel, an astronomer at the Tartu Observatory in Estonia and a co-author on the study. Since they’ve only found a few systems of this scale, astrophysicists aren’t sure whether they always form wall-like structures or if the one’s they’ve seen are special cases. The next step is to run simulations of the shapes that superstructures this massive tend to form, Tempel said.

Superclusters have their origins in pools of dark matter that formed early in the universe’s history, said Brent Tully of the Institute for Astronomy at the University of Hawaii. Normal matter flows towards the wells of dark matter, giving the universe its web-like structure.

While Tully agreed that the BOSS Great Wall is indeed the biggest structure in the universe we’ve found so far, he doesn’t think it will change our theories of how the cosmos gets its shape. (There is another contender for largest structure in the universe, but instead of being made of something, it’s made of nothing.)

“It is not surprising that if we look at a bigger patch of the universe we find something bigger,” Tully said. “But not so much bigger that it disrupts the generally held view of structure formation.”

What’s more, Tully said that the BOSS Great Wall won’t be the last word on giant superstructures—there’s plenty of universe left to explore. “Look in a new place and you’ll find something new,” Tully said.

Astronomers already know where to look next. Lietzen explained that the survey data the team used to figure out the large-scale structure of objects only covered a quarter of the night sky. “There could very well be another equally big system of superclusters somewhere in the Southern sky, for example,” Lietzen said.

http://www.pbs.org/wgbh/nova/next/p...so-big-it-could-rewrite-cosmological-history/
 
New Horizons imagery reveals small, frozen lake on Pluto
March 28, 2016

newhorizonsi.jpg


NASA's New Horizons spacecraft spied several features on Pluto that offer evidence of a time millions or billions of years ago when – thanks to much higher pressure in Pluto's atmosphere and warmer conditions on the surface – liquids might have flowed across and pooled on the surface of the distant world.

"In addition to this possible former lake, we also see evidence of channels that may also have carried liquids in Pluto's past," said Alan Stern, Southwest Research Institute, Boulder, Colorado—principal investigator of New Horizons and lead author of the scientific paper.

This feature appears to be a frozen, former lake of liquid nitrogen, located in a mountain range just north of Pluto's informally named Sputnik Planum. Captured by the New Horizons' Long Range Reconnaissance Imager (LORRI) as the spacecraft flew past Pluto on July 14, 2015, the image shows details as small as about 430 feet (130 meters). At its widest point the possible lake appears to be about 20 miles (30 kilometers) across.
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http://phys.org/news/2016-03-horizons-imagery-reveals-small-frozen.html#jCp
 
Blue Origin reused their suborbital booster for the second time today (3 uses overall). Not bad.
 
SpaceX stuck the landing at sea! Looked a bit choppy, too.

 
First stage, so it's only suborbital and comes back down pretty quickly.
 
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