What Mysteries Lie Between the Galaxies?

[kechloo]

Hello,

Well, first, I’m sorry if I’m doing mistakes in the english… (not my first language). I’m not profesionnal on physics and astronomy but I’m really curious.

I have somes basics questions :

Where is the place of our solar system in the milky way ?

Is it possible to have like « physical bodies » in between the galaxies ? or it’s just empty ?

If I understood well, The birth of stars and planets start the same but after there is a differentiation ? Where are they born ? All the stars and planets are located in solar systems ?

Thanks :D

 

[Matterwave]

1. This is easily google-able, see here: https://Earth'sky.org/space/does-our-sun-reside-in-a-spiral-arm-of-the-milky-way-galaxy
2. In between the galaxies is mostly just empty space. The inter-galactic medium exists (a very diffuse gas), there are dwarf galaxies, and there could be a few stars and other objects which were ejected from nearby galaxies. But mostly empty space.
3. The current theory of planetary formation is that they are made by the "left over" material nearby newly formed stars (or proto-stars). "Solar system" refers to our specific system (since "Solar" refers to our specific star - Sol or "The Sun"), but most (likely all, though I'm not sure) currently detected exoplanets are in planetary systems orbiting stars. Planets, in theory, can be located outside of planetary systems if they get ejected. If they are ejected though, firstly they become very difficult to detect since they don't really give off light, and secondly they may no longer be classified as a "planet". One would have to consult the IAU definition of a planet...but iirc, a lone compact rocky or gassy object not orbiting a star would not qualify as a planet.

 

[Janus]

Hello,

Well, first, I’m sorry if I’m doing mistakes in the english… (not my first language). I’m not profesionnal on physics and astronomy but I’m really curious.

I have somes basics questions :

Where is the place of our solar system in the milky way ?

Here's a picture showing the Solar system's location in the galaxy:
https://en.wikipedia.org/wiki/Solar_System#/media/File:Milky_Way_Arms_ssc2008-10.svg

Is it possible to have like « physical bodies » in between the galaxies ? or it’s just empty ?

There are "rogue stars" which are not gravitational bound to any galaxy. They were most likely born within galaxies and then later ejected by some interaction.

If I understood well, The birth of stars and planets start the same but after there is a differentiation ? Where are they born ? All the stars and planets are located in solar systems ?

Thanks :D

Star and their planets form in stellar "nurseries", these are gas and dust nebula which are dense enough for material to condense into a star system. Most of the material ends up forming the star( or in many cases stars, as systems with more than one star are common.), but some of it remains circling it and forms planets. The basic difference between a star and planet is whether or not fusion is occurring at its core. There is a intermediary object known as a "Brown Dwarf", but the line between "large planet" and "small brown dwarf" is a bit blurry.

There are "rogue" planets which wander in the regions between star systems, bit these were formed in star systems and then ejected (Buring the early stages of planetary formation, star systems can be crowded and a bit chaotic.)

 

[kechloo]

Thanks a lot for your answers :)

 

[berkeman]

Here's a picture showing the Solar system's location in the galaxy:

Technically, that would be an "illustration"...

 

[sophiecentaur]

Is it possible to have like « physical bodies » in between the galaxies ? or it’s just empty ?

An interesting thing about deep space is that the amount of matter out there is about one proton on average in each metre cube of space. It's one of the many things about Space that are just very hard to comprehend, A very deep vacuum but NOT EMPTY.