Monday, November 1, 2010

Galaxies

I didn't take this pic, but I wrote the post! Check it out!



our galactic neighbor, andromeda.

we are speeding towards each other! and in several billions of years andromeda and the milky way will collide. once the supermassive-black holes in the center of each galaxy get close enough they start to orbit each other. eventually, one will devour the other. it sounds scary, but its likely that not even a single star will collide in the process, given that there are a few lightyears between each one. that, and who knows what the state of the known universe will be like in billions of years. humans have only been around for 1/4000th~ of that time.

notice all the tiny red blots around the galaxy? each one is a nebula caused by a star that has exploded most likely via a supernova. it's the gas that made up the star but spread out in vast, unfathomable distances - no longer compressed under the intense gravity of the star. each one is comparable to the orion nebula under orion's belt. eventually they get to a point where it collapses again and becomes a new solar system! the universe is just a series of births and deaths of stars as well as the gravity that holds them all together.

next, see the white blob below andromeda? that's a separate, smaller galaxy. and that's relative, because that little guy has hundreds of millions of stars, each with the potential to have life on the planets as well as on the moons around the planets.

it should be noted that 99% of the stars you see in this picture are in the milky way, as we sit somewhere in the outer middle of its spiral arms. no matter where you look you're going to see stars - which is why when you look at "the milky way" you're actually looking towards the center of the galaxy, through layers of dust and stars. you can also easily tell which stars burn hot and which don't - the blues are scorchers and the yellow/red ones are old cooler ones just waiting to explode.

check out the high resolution, it's worth it:

http://apod.nasa.gov/apod/image/1001/M31_HALRGBpugh.jpg

Saturday, October 30, 2010

Comets

Didn't take this picture! But come in, read about comets :D



This is a picture of the comet Hyakutake, it entered Earth's orbit in 1996. 

Comets are some of the most interesting objects in solar systems for a number of reasons, including the fact that they are the source of all the meteor showers that we experience on Earth. 

First of all, its worth describing the difference between comets and asteroids. They exist amongst planets and moons as the four main types of objects in our solar system. When the solar system formed as a large, spinning disk of matter (hotter on the inside, colder near the outside), not everything could make it to be as big as planet, or even a moon. On the inside, the hot rocky material left over eventually would form the asteroids, and on the outside, the colder, icy material would form the comets. Think of comets as an asteroid-snowball. 

Anways - as comets approach the sun from the outer solar system they resemble asteroids, until they get close enough. As you can see in the picture, a cometary tail forms. This tail is made up of two different tails (as pictured), a dust tail and an ion tail.

The DUST tail (which is the one rising up towards the top of the photo) is pushed off of the comet due to the sun's radiation. It is free to flow about space as it may. 
The ION tail, (which is the one going straight back in a line, horizontally) is caused by the solar wind's charged particles reacting with and sweeping away the neutrally charged particles in the comet's nucleus. The ion tail always points directly away from the sun, even when the comet is on its way out of the solar system. This looks pretty weird, actually.

Now on to meteor showers - when a comet passes through Earth's orbit, the debris in the tail lingers for a very long time. When the Earth passes through the debris, its gravity attracts a lot of it, and when it falls into our planet's atmosphere, we see it streaking along the sky as it burns up into nothing.

It's also worth noting that usually all the shooting stars you see are incredibly dense pieces of space rock the size of a grain of SAND.

Crescent Moon & Venus on a Date

They were close together in the sky earlier this month so I snapped a pic! See how Venus is a crescent as well? That's because she's closer to the sun that we are on the Earth, so it goes through phases much like the moon from our point of view.

Friday, October 29, 2010

Old Old pic, first star trail pic I ever did

Here's the first star trail pic I ever did! I much prefer the one that I took that I put in the first post of my blog, as it has cool scenery in it, but this one turned out better in my opinion. The difference between the one here and the one in my first blog post, is that the one in the first blog post had the Full Moon out so it looks like day time in that one, while still being able to see stars!

This was done as a long exposure with the camera pointed at the north star, Polaris. All stars appear to rotate around polaris due to the Earth rotating in space. Stars closer to Polaris move in a very tiny circle, while the ones farther away make a huge swoop. I had to cut this off early as the clouds started rolling in as you can tell :)

Orion Widefield

Here's another from my excursion last night

Notice the star in the top left, how it's orange compared to the rest? That's Betelgeuse (pronounced beatlejuice), and it's more than 1,000 times bigger than our sun. It's older, and could blow up into a supernova at any minute. It might already have, but we wouldn't know because it's several lightyears away.

It's older, which means it's colder, hence the orange. The hottest stars burn blue.

Turned the camera on myself :)

This is from the same excursion, I'll post them periodically as to not clutter up my blog!

Already got some snow on the mountains out here once you reach the right altitudes.

Notice that little blob of stars to the left of the tip of my hat? That's Pleaides, or what the Japanese call "Subaru", which is why the Subaru car logo is a cluster of a few stars :) Fun fact.

Fall!

Well Fall's getting started here in Colorado. Here's an HDR image I did of the creek by my house!