It’s no secret that the universe is growing. However, research leads us to believe that our own Milky Way Galaxy is growing as well. In fact, our galaxy exhibits cannibalistic behavior, absorbing material from the dwarf galaxies surrounding it. We know that the chemical makeup in the central bulge of our galaxy differs from the chemical makeup of the outer halo of our galaxy, and we have also found that the chemical makeup of the outer halo of our galaxy is similar to the chemical makeup of stars found in dwarf galaxies orbiting our galaxy – namely, the Large Magellanic Cloud and the Sagittarius Dwarf Elliptical Galaxy. Therefore, these dwarf galaxies may simply be the leftovers of galaxies that were long ago absorbed into our own galaxy.
Milky Way Galaxy
Astronomers believe the key to understanding the growth of our galaxy is learning more about the dark matter around our galaxy. The halo of dark matter surrounding our galaxy actually exerts a gravitational force on smaller, neighboring galaxies, so it may be that dark matter is ripping away stars and pulling them into the external regions of our galaxy. There are still so many unanswered questions about dark matter and dark energy, but a project called the Dark Energy Survey is currently underway, in which we are using a tool called the Dark Energy Camera to detect stellar streams. Stellar streams are groups of relatively few stars that have been ripped away. They are difficult to detect because we are looking for a small number of stars in such a large region of space. Nevertheless, these stellar streams illustrate how our galaxy is constructed from smaller galaxies, so the future findings of the Dark Energy Survey should prove exciting!
The European Southern Observatory began construction of the European-Extremely Large Telescope (E-ELT) back in 2014. This telescope is on track to be the world’s largest optical and infrared telescope by the time it is completed in 2024, thus living up to its name. The E-ELT will include a main mirror that is 128 feet in diameter, beating out some of its competitors, such as the Giant Magellan Telescope and the Thirty Meter Telescope, which boast main mirrors that are 82 feet and 98 feet in diameter respectively. This telescope will be able to capture images 16 times sharper than images captured by the Hubble Space Telescope.
The E-ELT will be used to study exoplanets, dark matter, supermassive black holes, galaxy formation in the early universe, and much more. Observations from this telescope may be able to answer questions such as if the laws of nature really are universal, and we may be able to learn more about stellar populations at distances of tens of millions of light-years away from us. The E-ELT will be operating in northern Chile’s Atacama Desert, an ideal location for astronomical observation due to the dryness of the air and the clarity of the night sky. However, Chile, like most other locations in the world, still suffers from light pollution, so efforts to limit blue light emissions and luminous signs have come about.
Astronomers hope the E-ELT will be in use for at least 30 years. At a price of $1.4 billion, I would sure hope so. The more technology advances, the more we will be able to learn about our universe. The farther distances we will be able to look out to, and the more we will be able to essentially look back in time. I’m excited for the astronomical discoveries bound to emerge. However, given the fact that we have just over six and a half years left until the E-ELT’s first light, we’ll just have to be patient for now!