All the shiny things in the sky suns from other solar systems?
Question:
Are all of these other suns from other solar systems in our same galaxy (Milky Way)?
How many other galaxies are there? how do we know?
Answer:
SUN, MOON AND TEN OTHER LOCAL OBJECTS ARE ONE SET OF EXCEPTIONS
There are six planets in our own solar system that are visible to the naked eye under good sky conditions (no city lights, no clouds or moon) (though not all the time): the five known from antiquity (Mercury, Venus, Mars, Jupiter, Saturn) and Uranus. In addition the four brightest (largest) moons of Jupiter (Io, Callisto, Ganymede and Europa) are 5th magnitude at their brightest.
"SOLAR SYSTEM" IMPLIES THERE ARE PLANETS AROUND A STAR
Whilst most of the other points of light are stars and those stars are all members of our own galaxy THAT DOESNT MEAN THEY ALL HAVE PLANETS AROUND THEM, So far we know of only 210 extra-solar planets (all in our galaxy) and there are some 200 billion stars in our galaxy,
There are some exceptions to the statements "they are all stars" and "they are all in our galaxy" to note however:
M31 The Andromeda Galaxy 2.5 million light years away, is the nearest barred spiral galaxy to our own, Magnitude 4.36.
M33 The Triangulum Galaxy 2.6 million light years away, is the second nearest spiral galaxy to our own, Magnitude 6.3.
Large Magellanic Cloud: magnitude 0.9 at a distance of about160,000 light-years.
Small Magellanic Cloud: magnitude 2.7 at a distance of about 200,000 light-years,
Until the discovery of the Sagittarius Dwarf Elliptical Galaxy in 1994, they were the closest known (dwarf) galaxies to our own.
However these four objects, though not part of our galaxy, are all members of the Local Group of Galaxies. so it may be the case that everything visible in the sky is part of the Local Group,
THE NUMBER OF STARS IN THE UNIVERSE
70 Septilion (7 x 10^22) is the current best guestimate, arrived at by astronomers at the Australian National University
They did this by studying star densities in sample spaces and then working out how many such spaces there are in the observable universe.
Here is an edited version of one article reporting this:
"70 sextillion stars in the 'known' universe!
According to a study by Australian astronomers there are 70 sextillion (70,000,000,000,000,000,000,00... stars in the known universe.
It's also about 10 times as many stars as grains of sand on all the world's beaches and deserts.
The figure was calculated by a team of stargazers based at the Australian National University.
Speaking at the General Assembly of the International Astronomical Union meeting in Sydney, Dr Simon Driver said the number was drawn up based on a survey of one strip of sky, rather than trying to count every individual star.
The team used two of the world's most powerful telescopes, one at the Anglo-Australian Observatory in northern New South Wales state and one in the Canary Islands, to carry out their survey.
Within the strip of sky some 10,000 galaxies were pinpointed and detailed measurements of their brightness taken to calculate how many stars they contained.
That number was then multiplied by the number of similar sized strips needed to cover the entire sky, Driver said, and then multiplied again out to the edge of the visible universe.
He said there were likely many million more stars in the universe but the 70 sextillion figure was the number visible within range of modern telescopes."
LIFE ELSEWHERE IN THE UNIVERSE?
Almost certainly
Nearby and able to communicate with us?
Not necessarily
YES
YES
BILLIONS - cannot be counted
We know because they have tried to count them and can't
Apart from the Moon, other planets in our Solar system that are visible at times and the the odd asteroid and comet or two, yes. As far as we know, there are countless galaxies in the Universe. As for life forms on distant planets, I would say that it's a 100% certainty and that we would be fools to think otherwise.
yes, yes and infinity
As other posters have pointed out, several of the brightest objects in our sky are actually other planets in the solar system. You can also occasionally see (man-made) satellites passing overhead.
But yes, most of the stars we can see are actually suns in other solar systems. Most of them are from our own galaxy, although some of the things that look like stars are actually whole galaxies with millions of their own suns (you can't see individual stars in other galaxies without a massive telescope though).
Current thinking says that the universe is finite, so the number of other galaxies is not infinite - although it is very large and may be hundreds of billions.
And yes, my own suspicion is that there probably are other life-forms out there. Whether we'll ever be able to communicate with them is a different question.
Most of them are but like 2 maybe less are planets in our solar system, eg mars. Yes all the stars you see are in the milkyway galaxy
THere are billions of them maybe even a googol. We cannot possibly know cause we cant see them
All the shiny things in the night sky are stars, comets, or meteriods but mostly stars and there all from the milky way galaxy. The rest of the stars in other galaxies are not visible to the naked eye. There are many of other galaxies out there. Lets put it this way, if you counted each grain of sand in the world thats how many galaxies there is in the universe.
There has to be another Solar System somewhere, but not each star has one. The star has to be the same size and heat with good enough planets to have a proper Solar System.
TO ALL RESPONDENTS. The milky way is the band of stars which are the stars in our galaxy seen edge on. Think of our galaxy as a dinner plate and we, and our solar system, that is the sun and 9? planets orbiting it, are somewhere about 3/4 the way across and the edge being the milky way. What we see either side of that band is in general, deep space This is very simplistic but should give you the idea. Have a look at the link below.
a large majority of the shiny things in the sky are in fact stars however a small minority are planets the reason planets shine is due to the light reflecting from the sun. the sun is in fact the only sun because that is the name of our star. there are to many stars to name and that is why everybody makes the same assumption of every star being known as the sun
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