NASA releases 1.5 gigapixel photo of the Andromeda galaxy

[Cuddly]

hey that's my favorite galaxy! i always wanted to live there ever since i discovered it.

and it's gonna merge with the Milky Way some time in the future, for those who didn't know. so. that's our future right there.

Uh? Do tell more.

[shirogane]

Uh? Do tell more.

First of all, sorry for answer this instead of meridannight.

Our galaxy and Andromeda galaxy move at the same time and will merge into each other in about 4 billion years from now. You can see it here

http://en.wikipedia.org/wiki/Andromeda%E..._collision

And lucky for us because it happen before Sun explode and kill us all ( or the collision kill us first )

[SHOman93]

OMG can I just print out this as a poster and put it on my wall? Fricking amazing is all I will say.

[meridannight]

Uh? Do tell more.

the Andromeda Galaxy is approaching us. it will likely collide with our galaxy, the Milky Way, because its sideways velocity is so small as to allow direct collision, in a time frame that is estimated to be about 4 billion years. as a consequence the two will merge to form one single galaxy.

Andromeda on collision course with the Milky Way

what happens to the Sun?

http://mnras.oxfordjournals.org/content/386/1/461

with our understanding of the life cycle of the Sun, this will all happen when the Sun is still a main sequence star (it will start entering the red giant phase in about 5 billion years). the Sun is currently ca 4.6 million years old.


however, as a main sequence star, the Sun's luminosity will increase in that phase and some say that it increases enough to raise the temperature on Earth such that all its water will evaporate into space in the next billion years. the planet will not be able to support life then. so, we wouldn't be around to see the merger between our galaxy and the Andromeda, unless we do something to populate another planet/satellite by that time.

however i cross-referenced this data from one of the books on astronomy i have in my library and there it was said that the Sun will more or less keep its present luminosity for ca 4 billion years. that was a book from 1982 though. i have to do some research on this subject to understand what's the most likely scenario here. (although it really is too early to take any of these possible scenarios regarding the Earth seriously yet. it's a billion-years time scale, after all).

what we do know as of current calculations is the Earth will be around when the Andromeda and the Milky Way merge (when the Sun enters the red giant phase it will probably pull the Earth in), but whether it will still be able to support life by then is a question mark.

[meridannight]

And lucky for us because it happen before Sun explode and kill us all ( or the collision kill us first )

the Sun won't explode. it doesn't have enough mass to do that. it will expand. there's a huge difference. it will become a red giant, and when it does, it will most likely engulf the Earth (although this is still an open argument). skipping forth, eventually the Sun will become a planetary nebula and a white dwarf. the white dwarf is said to survive for trillions of years whereas the nebula will gradually fade long before then.

and the collison won't kill us. lols.

in an encounter between two galaxies the individual stars fly right by one another, suffering only gravitational deflections produced by the entire collection of stars. the interstellar gas clouds might bang together inelastically, but the collection of stars would tend to conserve its total energy. the stars might, however, transform one kind of energy into another kind, say orbital energy into random motions.

[JackTX]

And lucky for us because it happen before Sun explode and kill us all

Awwwwwww! I wanted to be blowed up by the sun! NO FAIR!

I have a decent telescope but the mount froze up and I either need to re-grease it (*snort*) or buy a new one. Suckers aren't cheap either!

[meridannight]

[MENTION=21947]JackBoneTX[/MENTION] the Sun won't ever explode. that was an erroneous term that he used.

[princealbertofb]

Wow, Londoner! Once more, you steal the show!!! :biggrin:

[meridannight]

the Sun is currently ca 4.6 million years old.

i meant 4.6 billion. lols.

[JackTX]

[MENTION=21947]JackBoneTX[/MENTION] the Sun won't ever explode. that was an erroneous term that he used.

It wouldn't go supernova eventually if our galaxy was left alone?