i guess
Earth is the only planet we know of that has living creatures inhabited on it, Although even with our greatest technology today we cannot see other galaxies. There are millions of stars in our galaxy that could have planets near by. With a heat source it would be possible for creatures to live on. There are many Galaxies and highly likely that there is another planet out there that has many creatures living as innocently as us beings on planet earth, although communication would be near to impossible.
To know what is the life there, and if there's any other creatures or "aliens". some scientists are looking for planets with water and life on them.
Aliens are either citizens of other countries or, in science fiction terms, creatures from other planets/galaxies. How much are they? It depends on the jobs they are hired to perform.
who discovered the galaxies who discovered the galaxies
Spiral galaxies, barred spiral galaxies, elliptical galaxies, and irregular galaxies
The possessive form for the plural noun galaxies is galaxies'.Example: Their galaxies' paths do not coordinate.
Elliptical galaxies are sometime called dwarf galaxies.
15 Galaxies? There are over 1,000,000,000 galaxies possibly more.
All information on this subject is philosophical speculation. Absolutely NO good evidence exists (but there are some fuzzy tales and faked photos..). But there are some compelling arguments for there being a lot of strange creatures in the galaxy (our local swirly home) and beyond. And if there ARE lots of other guys out there, WHERE ARE THEY?!! Why haven't they said "Hello"? (Search: Fermi's Paradox ) Here's one stumbling block to consider-- There are FAR more stars in the universe than grains of sand on all the beaches on Earth--and ten or so times as many planets. So if there are 200,000,000,000 highly advanced, technologically-developed civilizations in the universe--the odds would indicate that there still might not be another one in this galaxy OR EVEN THE NEAREST neighbor galaxies.
no galaxies are not harmful
spiral galaxies (ours), irregular galaxies, and elliptical galaxies.
You can have dwarf elliptical galaxies.