First Part Of Ananda Sutra
Monk Ananda once said to Lord Buddha, "Great mentor I had heard from you that one enlighten monk called Abhigu in Sibhi Buddha's time, went to one of great heaven then sent his voice over the whole galaxy. So tell about Lord Buddha's limit of sending voice? Buddha said to Ananda "Abhigu was only monk, Lord Buddha's voice limit can't be measured". But Ananda thero didn't satisfied and ask same question in another two times. After silence in third time , Lord Buddha said to Ananda "Do you know about galaxy?". Ananda thero request to do great roaring about universe.
Part about Milky Way Galaxy
               "Ananda, if sun with moon orbit somewhere by lighting towards all directs, those area was called as one galaxy (Sahasri Loka Dathu). In one galaxy there have 1000 moons, 1000 suns, 1000 lands like India, 1000 oceans, 1000 mountains like Himalayas, (that means 1000 planets with living beings), 1000 great kingdoms, 1000 heavens of four region, Tutisa, Yamaya, Tusita, Nirmana Rathi, Parinirmitha Vasawarthi and great heavens. So this galaxy was named as little galaxy (Chulani Loka Dathu - which means our Milky Way Galaxy)".

Review One
             According to this section we can conclude Lord Buddha knew from his ESP powers that there has 1000 set of plants which accomplish with living being like human. Also those planets has there own sun , moon and set of heavens. Sometime parallel universe concept in black hole theory in modern physics can be link with this sutra. Also Black Holes discussed in Anadakara sutra (Sutra about great darkness - "Monks, there have one world where have only darkness. In all directions filled with great darkness. But person who don't know about four noble truths, their minds also dark more than that world.") And Tathagatha Achcharieya sutra ( Monks in space there have world which is open from, front side & end side, to space and accomplish with great dark which make invisible to human eye........). In Buddhist Cosmology  life on earth originated from great heaven of light (Abassara Brahma Loka), according to Agghagha Sutra. Also that sutra said universe is continually collapsing & expanding. When universe collapsing, earth is destroyed and people do meditation merit then born in great heaven of light. When universe expanding earth is re-formed & creatures formed from those god's desires.

Part about galaxy clusters
"Anada this little galaxies are multiply by 1000 there occur two-hundreds central galaxies. Ananda when this two-hundreds central galaxies are multiply by 1000 there occur three-hundreds great galaxies. So Ananda if Lord Buddha want to spread his voice around this three-hundreds great galaxies, it can be done. Even if Lord Buddha want to spread his voice around far away than this three-hundreds great galaxies, it also can be done."    

Part about modulating waves
           "Anada, in here Lord Buddha spread his moral light of body around the three-hundreds great galaxies and living beings are heard Lord Buddha's voice within this light". 

Review Two
In second section galaxies put into cultures and name given to them. Third part include concept which still not found in science - speech waves modulated into light waves. Final part of this sutra Lord Buddha said to Ananda thero that if some one make devotion to Lord Buddha's knowing about universe, he can be collected merits same to becoming main god of heaven called Twsita in seven times and becoming ruler of kingdom to all over the world in seven times. Actually we need to find about heavens and life in other planets by moral experiment such as hypnotism.