Exeter's space thread!

So I'm a big space nerd and really don't want to keep dumping stuff in the WIOYM thread when I could just create a place for it!

Tonight I'm thinking about the James Webb Space Telescope, set to launch in October 2018. I've been hyped about this monster for years and just thinking about it gives me chills.



It's had a rough journey financially, but it'll be far beyond the value of the investment in scientific returns. James Webb is gigantic, with a composite Beryllium and gold-plated mirror 6.5 metres in diameter. Light will be collected in three stages, called a three-mirror anastigmat. The telescope is designed to view infrared light, and peer into the deepest depths of cosmic time, to learn about star and galaxy formation, as well as the early life of the universe. It will operate in remarkable cold thanks to the 5-layered sun shield that will unfold to the size of a tennis court. James Webb will be sitting pretty a million miles away, far beyond the orbit of the moon, orbiting the L2 Lagrange point, where gravitational influences from the Earth, Moon, and Sun effectively cancel each other out.




Hubble was launched in the cargo bay of the Space Shuttle Orbiter, and Hubble was the size of a school bus. James Webb is FAR larger, so the only way with current rocket technology to get it into space is to fold it into a ludicrously small compartment on an Ariane 5 rocket. I absolutely had to include video of the deployment because it has to be seen to be believed.



First the solar panels deploy. James Webb will orbit L2 in such a way that it will always have sunlight, and never be in the Earth or Moon's shadow. Next, the sun shields will extend and the ISIM will rise up to operational position. The sun shield will unpack itself and spread out to full size. The 5 layers will separate and create a protective thermal shield, keeping the mirror cool enough that it will receive the most minimal possible heat interference from the the sun, the Telescope's own instruments, and even Earth itself. Once the tennis-court sized sun shield is fully deployed, the two-storey tall mirror will be completed. The Secondary reflector will fold into place, and the remaining six mirror segments will be swung into place, creating a curved mirror with a collecting area of 25 m² (270 sq ft). Each mirror segment is movable in tiny increments, allowing the mirror to do some truly unprecedented work. On the ground you have to adjust your mirrors by tiny increments to account for the atmosphere swimming above you. That's why stars twinkle. Not so in space.



I hope you're as excited as I am. This beautiful technological marvel is going to answer deep questions in astronomy and cosmology. April 24th of this year will be Hubble's 25th year in space. Here's to 25 years of science for the next generation.

 

I remember hearing about the JWST!!! I'm an amateur astronomer and just the thought of the wealth of knowledge it will bring us.....it makes me so incredibly happy. :3 Do you mind if I add to your thread and post some of my favorite space pictures?

 

If there's an amateur astronomer in our midst I expect nothing less than posting all kinds of stuff! Please, go right ahead! ^^

This thread is open to everyone so please, post away! I'll try and post some photos and space news every day!

 

Beautiful! :3

 

Ooh, space! Count me in if I think of something I can add to the discussion!

 

Here's some cool shots of M51, the Whirlpool Galaxy. The smaller lump next to it is actually another galaxy, NGC 5195, drifting behind it. They're interacting to form a large number of stars in those pink regions you see in the top image. Dust and gas are clumping together in those dark tendrils on the arms and forming stars as the materials condense and eventually shine.

The top image is a Hubble image, composed of several wavelengths of light, both visible and infrared. (435, 555, 658, and 814 nanometer to be exact).



The bottom image is from the Chandra X-ray Observatory, another orbiting telescope. X-rays are largely absorbed by the Earth's atmosphere so space is the ideal place to capture them. The pink regions in this image are extreme sources of X-rays, like black holes, or tiny, city-sized (but still stellar-mass) neutron stars orbiting a regularly sized companion. The fact that there are so many regions in M51 that show so much X-ray activity is one of the reasons we conclude that M51 is producing a lot of new stars.

 

I just shiver at the sheer thought what that James Webb telescope give us. If Hubble was able to do some really epic photos, then just imagine what this monster will be able to do.

I'm of course waiting for more space photos! I might even include something myself if I'll find anything.

 

Just found a neat game called Super Planet Crash, which is a gravity simulator, allowing you to dump planets and dwarf stars into a star system. The challenge is to create a balanced system that can last 500 years. It's very difficult given that you're constrained to one AU of workspace (AU = astronomical unit, the distance between the Earth and the Sun.)

Happy planet destroying!

http://www.stefanom.org/spc/

 

Also I thought it would be cool to talk about planetary nebulae.

They get their name from the eminent astronomer William Herschel. In his telescope their round shapes seemed to resemble planets. A principle of science is that often, when something is named, the name doesn't change simply because it's later shown to be something else. Nomenclature works its way into other fields and ties our understanding of the world together. Changing terminologies is a rare occurrence unless it's a significant dfference. There are numerous examples in biology of preserving old errors, and I'm sure anyone who's learned anything about electricity will have wondered why a surplus of electrons makes an object "negatively" charged.

But I digress.

Planetary nebulae result from the later stages of large red giant stars' lives. The star throws off its outer layers as the fusion in the core stops. The exposed, bright, hot core emits enough radiation to ionise the gasses as they dissipate, causing them to glow in a variety of wavelengths. Planetary nebula can take many forms, the simplest being a relatively uniform shell, the more complex being the results of the interaction between the gas and something local, like a smaller companion star, carving a path through the gas and twisting it into shapes through gravity and the force of stellar winds. Here are some lovely examples.

In a few of these, you can see the stellar core still glowing towards the middle. Try and spot them!

 

This game also looks fun to try - Universe Sandbox. It's not free , but IMO for $25 you get so much possibilities it's great. (I don't own it though, so this is based solely on the gameplays I have watched)

 

Don't take this the wrong way, but let me just whine for a moment that there are no fellow astronomy lovers anywhere near me that are as smart and sweet as you are. Your mate is a lucky man! :3

 

It's the one thing I never get tired of learning ^^ I taught one boyfriend everything he knows about astronomy and the other knows as much as I do, it's one of the reasons I fell in love with him ^^

 

Just a quick post about gravitational lensing!

Gravity can bend light, if you have enough of it. Light travels in straight lines, but objects with enough mass can actually curve the geometry of space, so that those straight lines can in fact curve right around something. One major proof of general relativity, the theory that describes the modern understanding of gravity, was the appearance of stars around the sun as we moved in our orbit. We know where the stars are supposed to be, and any other time you look at them, they have a fixed relative distance to their neighbours. But when those stars are peeking out from behind the sun, they appear just a little bit early. That is the effect of their light being slightly bent around the sun. That effect occurs on the grandest scales as well. Einstein just didn't think we'd ever see it. He was wrong, luckily.

One incredible phenomenon in the universe is gravitational lensing of galaxies. This happens when a galaxy, on the other side of a large cluster of galaxies, can have its light bent around that cluster. Of course, clusters of galaxies aren't lens shaped, and aren't really shaped like anything other than a clump of moving matter, and their mass is distributed in a complex manner. So you don't get a clean, simple lense effect. What you see in this image is one distant blue galaxy. But you see its light being bent and distorted in many directions and from many different angles. As a result, this same galaxy appears in multiple places in the image.



What's so cool about this is it actually tells us some interesting things about how much matter is in the universe, the overall geometric shape of the universe, and how much dark matter is out there. We can actually calculate how much matter is in those galaxies and determine that it's not enough to lens the blue galaxy. The missing mass is all contained in mysterious dark matter, which makes up most of the mass of that cluster. We can take that information and extrapolate outward to figure out how much matter and mass there is in the entire universe, and use that to figure out the shape of the universe itself. Clusters of galaxies are the largest objects in the universe and help us understand how the stuff of the universe is distributed.

Here's a few more lensed galaxies for your viewing pleasure.

 

All so wonderful!!! Thank you for the science lesson...I needed a brush-up, lol. Have you ever considered teaching? Your manner, presentation and ability to get sometimes complex ideas across easily is a rare gift! Even if you don't, never stop learning!!
<3

 

You're so sweet, I just read a lot of good authors, that's all! I have no real education so what I absorb is essentially just popular science. I'm slowly learning more and more, but there are always technical elements that are out of my depth. Nothing is too difficult by definition, but I'm really just enjoying the easy parts. The hard stuff is far more important.

I just want people to get excited about space, there's always so much going on out there, so many experiments and missions taking place, so many discoveries.... We discover planets every week. I have to make a post about Keplar and how it's still detecting planets despite the fact that half of its reaction wheels don't work. It's absolutely crazy. I tell you, those NASA engineers, give them a few million dollars and they will land anything anywhere, or find a way to fix a probe launched in the late 70s from 500 million kilometres away, or figure out a way to bring an observatory back from the dead. Every time.

 

The V838 Monocerotis light echo. :3

 

If we're going to show a picture of V838 Monocerotis, we have to show a gif of the echo moving!



So what the hell is going on here? It's a wave of light moving through materials being ejected by a gigantic, cool star.


The star became suddenly 600,000 times brighter than the sun, making it the brightest star in the entire milky way. As light travelled outward, it reflects off progressively more and more distant layers of the materials around the star. You're not watching the cloud move, you're watching light move through it and make its layers shine.

 

Beautiful!!! I'll post more when I feel a bit better (had gallbladder surgery yesterday morning), I have a huge folder on my computer of all kindsa space awesome. :3