We know that galaxies like our Milky Way are far more massive than we can see. The dark matter in the Milky Way makes up 90% of it’s total mass. Another way of saying this is the Mass to Light ratio, comparing the total mass inferred by the rotation speed of the galaxy to the total mass of stars in the galaxy. This ratio, M/L, for the Milky Way, is about 10. But for a galaxy cluster, the M/L ratio is more like 100. Galaxy clusters are not just dense collections of stars and massive galaxies, they are also immense...
Beyond the atmosphere, past the stars we see, farther than the Milky Way, and continuing past Andromeda, we reach the real cosmic ocean. So called because like an ocean on Earth, it is vast, homogeneous, and impossible to navigate by common sense alone. In the cosmic ocean, an impossibly huge amount of space separates island galaxies, whose strong gravity binds them across incredible distances, dictating their course, and forming the largest and most massive structures in the universe: galaxy clusters. Because these immense structures are so vast and so distant, it requires the work of several telescopes to map out...
We are reaching the point in our study of exoplanets, planets orbiting other stars, where the atmospheres of distant worlds are within the limits of our technology. Once we could barely see the wobble of a star, the telltale sign of an exoplanet, and now we can see reflected starlight and study a distant atmosphere. Now we can probe deeper questions, are atmospheres of exoplanets similar to solar system planets? What are they made of? Do other solar systems have the same raw materials as ours? Do they have what we believe to be the raw materials for life? A...
Massive stars and low-mass stars live different lives. They are born in different environments, fuse different elements during the course of their lives, release different amounts of radiation across the electromagnetic spectrum, die in different ways, and enrich interstellar space with different metals. We see stars at all stages of life in the galaxy, and their study allows us to piece together how stars form, and how the rarest ones are different. The image above shows two distinct clouds, both about 5,000 light years away in the constellation Cygnus, along the Galactic plane. The smaller bubble on the left, literally...
What do other planetary systems look like? We have seen some where massive Jupiter-sized worlds orbit closer to their star than Mercury does to the Sun, baking them with radiation. Others have had multiple rocky planets within the Earth’s orbit distance. Some have planets similar to Earth in a variety of locations. But what about far away from the star? We never expected to find gas giants like Uranus and Neptune in the far reaches of our solar system. Are there planetary systems where planets live even farther away? Maybe there are planets that live in the empty darkness between stars,...
The Earth, along with the rest of the solar system, was born around 4.6 Billion years ago. At that time, Earth was part of the early group of habitable planets to form in the Universe. According to a new theoretical study from the Space Telescope Science Institute (STScI), the vast majority of Earth-like planets has yet to form. Using data from the Hubble space Telescope (HST) and the Kepler Space Telescope (KST), astronomers were able to come up with a theoretical model of cosmic evolution, detailing how planets will form over the entire lifespan of the Universe. “Our main motivation was...
If you wanted to look at weather and climate patterns on the Earth, you would put a satellite in orbit and watch the planet for a long time, looking for changes in the cloud layers and measuring wind speeds, etc. It isn’t a stretch to think that we could do the same for another planet, especially since most of the planets in the solar system have atmospheres. Jupiter, being the largest and heaviest planet, also has immense wind speeds and beautiful vortex features, some of which are larger than the Earth. But in order to understand these features, we have...
The only way we can understand the cosmos is to find new and innovative ways to interpret the light we capture from it. Using the largest and most technologically advanced telescopes in the world, we peer deeper into space, further back in time, and see photons that have spent eons travelling to Earth. If we can get rid of all of the other light from closer objects, and zero in on this distant light, we can begin to understand what was present at the beginning. Using data from deep sky surveys conducted by the Hubble Space Telescope (HST), astronomers from...
Maybe I am a starry-eyed dreamer, or maybe I just treat astronomy like a little kid opening birthday presents, but every time I see a new Hubble image I am blown away by it. Today’s mind-blowing photo is of Messier 63, the Sunflower Galaxy, located in Canes Venatici. It shows the central region of the galaxy and out tot he spiral arms. The arms are clearly visible due to the bright blue clusters of newly formed stars intermixed with dark patched of thick gas and dust. In between the arms lie older, redder stars. Closest to the centre, the yellowish...
Remember that amazing high-def photo of M31, the Andromeda Galaxy, from Hubble a few months back? It was able to separate the light from the galaxy into the millions of visible stars that populate its spiral arms. This image is used for far more than the wow factor of seeing another galaxy up close. It allows us to study the entire galaxy and gain insights into the lives of spiral galaxies beyond our own, how they formed, how they evolve, and maybe even how they will eventually die. By looking at the spiral arms of M31, where the youngest and...
