According to the best estimates by astronomers from around the world, there are at least one hundred billion galaxies in the observable universe. As for the parts of the universe we can’t see? Who knows. Within these billions (if not trillions) of galaxies are billions (if not trillions) of stars… Quite mind-altering, isn’t it? It is literally beyond our ability to comprehend.
1. New research coming from a team of international scientists led by Professor Heidi Jo Newberg of the Rensselaer Polytechnic Institute suggests that the Milky Way Galaxy is at least 50 percent larger than what is commonly believed. These estimates are based on new findings that reveal our galaxy is contoured into multiple concentric ripples. This means that the Milky Way Galaxy is not 100,000 light years across, but at least 150,000 light years across. (source)
2. At the center of the galaxy is a giant black hole which is billions of times as massive as the sun. Just imagine that… Here are a few images that will help you put that fact into perspective. Scientists believe that this black hole weighs as much as 4 million of our suns put together. Black holes are some of the strangest and most fascinating objects found in outer space. Scientists don’t know what they are, but theories range from portals to other dimensions and more. The first black hole was discovered in 1971. Our galaxy is hurtling through space, spinning around a giant black hole, while our sun and solar system travel with it. The solar system is travelling at speeds of approximately 515,000 miles per hour. Even at this speed, our solar system would take about 230 million years to travel all the way around the galaxy.
3. As mentioned in point #2, our galaxy is hurtling through the universe, and it’s not the only one. There are billions of galaxies out there, all doing the same thing. This massive collection of stars is constantly crashing into one another.
4. Our galaxy is home to (possibly) a number of Earth-like planets. Quite a few Earth-like planets have already been discovered, but a group of researchers from Australia and Denmark recently calculated that there are hundreds of billions of Earth-like plants in the Milky Way Galaxy:
“The ingredients for life are plentiful, and we now know that habitable environments are plentiful,” said Dr Lineweaver, who is a co-author on the paper submitted for publication in the Monthly Notices of the Royal Astronomical Society (arXiv.org preprint)
Using NASA data, astronomers have calculated for the first time that in our galaxy alone, there are at least 8.8 billion stars with Earth-size planets in the habitable temperature zone. (source)
It’s important to note that not all planets have to be Earth-like in order to support extraterrestrial life. Who knows what conditions are required for other lifeforms to exist? Their biological makeup could be completely different from ours, and it seems like pure hubris to assume otherwise.
The general, overwhelming scientific consensus is no, we are not alone (source), but not all agree that intelligent extraterrestrial life is, and has been, visiting our planet. That being said, many prestigious scientists, astronauts, academics, and more believe that the evidence for extraterrestrial visitation is quite solid. You can read more about that here.
5. Apparently, there is a strong possibility that the Milky Way and Andromeda galaxies will collide in about 2 billion years. That collision will last approximately 5 billion years. (The Milky Way [volume in Explore the Universe encyclopedic set]. 2010. Chicago, IL: World Book.)
6. Many scientists believe that the Milky Way is one of the oldest galaxies in the universe. Estimates place the formation of our galaxy at approximately 13.6 billion years ago, and the ‘Big Bang’ was said to occur 13.7 billion years ago. (Trammel, Howard K. 2010. Galaxies (A True Book). New York, NY: Scholastic Inc.)
7. Approximately 90 percent of the Milky Way is invisible. Stars and dust make up only 10 percent of the total mass of the galaxy, so where is the other 90 percent? Whatever it is, it does have mass, and scientists are calling it Dark Matter. (source)