Oh, isn't that a wonderful question, my friend? Scientists have discovered one universe that we all are part of. It's a vast and magnificent place that never fails to amaze and inspire. Just imagine all the galaxies and stars waiting to be discovered right before our eyes.
The extrasolar planets discovered so far most resemble those in our own solar system, including rocky planets, ice giants, and gas giants. However, there is a wide variety of exoplanets with unique characteristics that differ from those we find in our solar system.
What "other universes"? There is no clear evidence that such "other universes" even exist. If they do exist, it would likely make no sense to speak about how old they are NOW. Even within our own Universe, it doesn't make sense to speak about "simultaneity" between far-away points; this means that the word "now" is not clearly defined!
A few thousand exoplanets have been discovered so far; according to the Wikipedia article on "Exoplanet": "As of 1 March 2017, a total of 3,586 confirmed exoplanets are listed in the Extrasolar Planets Encyclopaedia".The Wikipedia article "List of exoplanets" has a list of such exoplanets.
There are only 8 planets so far (that have been discovered) in our solar system.There are also 4 dwarf planets (these are not proper planets).Starting with the closest to the sun:MercuryVenusEarthMars(Ceres - Dwarf)JupiterSaturnUranusNeptune(Pluto - Dwarf)(Makemake - Dwarf)(Eris - Dwarf)There are probably more - but these are the only ones that have been discovered.
Quaoar does not have any known moons. It is a trans-Neptunian object located in the Kuiper belt, and so far, no natural satellites have been discovered around it.
so far 63 moons have been discovered
Over 300,000
Only one has been discovered so far.
2 1/2
As far as we know, there is one Universe. There are hypothesis about parallel universes, but for now, there is no way to confirm that.
63 elements had been discovered so far.
There are (so far) three dimensions of space, and one dimension of time.
There are 26 transuranic elements that have been discovered so far. These elements have atomic numbers greater than uranium (92) and are all synthetic, meaning they do not occur naturally on Earth.
"multiverse" And its not really a theory as (so far) its untestable.
copper
Iron
Summer has been around as long as humans can remember, so nobody discovered it. As far as humans are concerned, it has always been there.