A future collision billions of years in the making

Although the universe is expanding, collisions happen all over. Planets collide, stars collide, meteors and comets hit planets, etc. However, sometimes larger "collisions" occur where no objects actually hit each other, but it's more of a merger. This can occur between galaxies and we have observed it occurring in different parts of the universe. Our galaxy, the Milky Way, is currently on a collision course with another galaxy called Andromeda. We know this because of the method of measurement used to determine how far away galaxies are from us. Edwin Hubble and other scientists in the 1920's, using the Doppler-shift method, observed many of these galaxies moving away from us at very quick speeds. They were able to deduce from this that the universe is expanding. This also became known as Hubble's law. However, Andromeda looked different in the observation.

Using this method of measurement, it was discovered that Andromeda is headed right for our galaxy. This collision, or merger, will not occur for another four billion years. However, if the earth is still here, it will drastically change what our night sky looks like.

It is unlikely that the stars in each galaxy will collide as they are very spaced out since these are two massive galaxies. I wish I could be here to see it because a night sky like that would be even more incredible than what ours looks like now!

Our Nearest Stellar Neighbor: Proxima Centauri

Let's take a moment to try to understand how vast the universe we live in truly is. Our earth is 24,901 miles in circumference. It is one planet of eight in our solar system. Our solar system is part of one star system. This star is known as our sun. Its gravitational pull causes all of the celestial objects in near proximity to orbit around it. This, along with the rotation of the earth, gives us our days and our nights. However, the sun is not the only light-bringer to the universe. We are surrounded by many of these stars yet they are too far away to really get the effects of their existence. This blog post tries to put that into perspective. Our nearest neighboring star, otherwise known as Proxima Centauri, is 4.243 light years away. As I have stated in my previous blog and many of you already know, a light year is how far light travels in one year. Considering that light travels exceptionally fast (almost 300 million meters per second), that is a great distance. But in the vastness of the universe, 4.243 light years is a stones throw away. We hope that one day, if the earth is uninhabitable and that the planets in our solar system cannot sustain life, that we can travel to this star system and inhabit it.

This may seem completely unattainable at this point in human existence, but it does not put it out of the realm of possibility. Scientists have studied our universe for decades and it seems that it is just under 14 billion years old. It is also 93 billion light years across, the observable universe, that is. So, when talking about distances this great, 4.243 light years doesn't seem that far away. Right now, Voyager I is on a path to a star system. It is travelling at 38,000 mph and is 11.7 billion miles away from us after 40 years since its launch. However, it will not reach this star system for another 40,000 years. The hope is that we can advance our space travel capabilities to the point where 40,000 years can turn into 20-40 years. This rate of travel would still be slow for intergalactic travel, yet would make it viable for expanding our species to other planets outside of our "mini" system of planets.

The use of SETI and the question of 'if aliens are trying to contact us as well, are they using the same method?'

The Search for extraterrestrial intelligence (SETI) has been occurring since the late 1800s. In as early as 1896, Nikola Tesla used his new wireless electrical transmission system to try to contact "beings" on Mars. This is basically how it all started in terms of the search. Even though his search failed, his curiosity using the radio technology has expanded the search greatly in the last 100 years. We now have radio telescopes all over the world that are beaming at hundreds of thousands of stars searching for radio signals that could be coming from an intelligent life-form. Radio signals penetrate the Earth's atmosphere very well, which means that we can beam those signals very far out into space and receive signals from very far away as well. This is why they believe it to be the most effective method in searching for intelligent life in the cosmos.

Now, the only thing that we do not know in the hunt for intelligent life is that if an intelligent civilization that is looking to make contact is using the same technology or not. It could be possible that other potential life-forms out there are using a different kind of technology to send messages that we have not discovered yet. This poses a problem because we could be looking right through potential habitable planets with intelligent life. However, many scientists believe that since they would be governed by the same principles (laws of physics), they should be utilizing radio waves as a means of long distance communication as it is very effective at long distances. The search continues and we will not be giving up anytime soon. However, I just hope that if we do make contact, it is not us giving away our location to a violent civilization that is way more advanced than we are (see movie Independence Day).