Today is the day, 25 years ago, that the Hubble space telescope launched from the Kennedy Space Centre aboard the Space Shuttle Discovery. The world had high hopes for Hubble, but we had no idea what great treasures were waiting for us in the depths of the cosmos. No piece of technology in human history has, arguably, had a bigger impact on our understanding of the Universe. For the 25th anniversary, International Astronomy day is coinciding to tomorrow’s anniversary of the deployment of Hubble, since it usually falls on a Saturday. Events across the world will include arts and crafts, Astronomy demonstrations,...
After yesterday’s post about some data that has caused us to rethink a theory, I wanted to follow it up today with an even bigger bit of data that could substantially change an even bigger theory. Dark energy was discovered as a large-scale repulsive force in the universe that is responsible for the acceleration of its expansion. It was discovered by looking at type 1a supernovae in distant galaxies. since the supernovae all explode with the same mass limit, they appear to all have the same intrinsic luminosity. If we know how bright they actually are, we can compare them...
Have you ever heard of an object called ‘Hanny’s Voorwerp?’ It’s a thin wispy ghost-like blob at the edge of a Galaxy. It was discovered by Dutch schoolteacher Hanny van Arkel in 2007 as she was classifying galaxies as part of the Galaxy Zoo project. Since then, astronomers have been studying its origin, as it was the first of a brand new phenomenon in astronomy. This past week, a new data set of wispy trails at the edge of Galaxies have been released as part of a Hubble study by Bill Keel of the University of Alabama, Tuscaloosa. The new Hubble...
The deeper we peer through the cosmos, the more we are looking into the distant past. Light from other galaxies takes millions of years to reach us, and so when that light has finally arrived at Earth, it is millions of years old, a snapshot in time of the distant galaxy. The furthest we can see is so far back in the history of the universe, that galaxies haven’t even formed yet. As we look at the large-scale structure of the Universe, we see it filled with a cosmic web of galaxy clusters, containing tens of thousands of galaxies each....
Today I found a few nice images that I wanted to talk about, and each one revealed something different about the object that was being imaged. I thought it would be a good chance to show everyone how astronomy is really the study of patterns of light, speaking from a minimalist perspective. We learn literally everything about the Universe beyond the solar system from the photons we see. From photons we can deduce the mass, distance, density, composition, behaviour, formation, and evolution of the cosmos. Pretty stellar! (pun intended) Here are some recent images and what we learn from them....
Cassiopeia A is the expanding remainder of a massive star that exploded 340 years ago in he constellation of Cassiopeia (hence we call it Cas A for short). As the star erupted, hot radioactive material was shot out in all directions, churning up the surrounding outer debris, before the star finally tore itself apart. Simulations of supernova explosions have found it difficult to model the extreme conditions during this process, even when using the world’s best supercomputers. So what are astronomers missing? By studying recent supernovae like Cas A, astronomers can study the processes that formed these massive expanding shock waves, leading...
You may know that the Universe is much more complex than we know. If you look at nearly anything in a different wavelength of light, new details can pop up that you’d never expect. Astronomers today use all the wavelengths of light to study the Universe. Even the most seemingly boring objects can come to life in different wavelengths. As a prime example, take the Moon. Now I don’t find the Moon boring at all, in fact it’s quite interesting and has a lot of influence on the Earth, so its fun to talk about. But when we look at...
Since Voyager 1 and 2 passed by Saturn in 1980 and 1981 respectively, scientists have wanted more information about the many amazing icy moons that orbit the gas giant. The follow up mission to Saturn, Cassini, has been in orbit around the planet for over a decade, and has since mapped the icy moons in their entirety. Take a look at some of the Voyager images and how they compare to the new colour maps from Cassini. I should note that the colours in the Cassini images are beyond human vision, extending into infrared and ultraviolet to add some further...
Yesterday I wrote about young stars that had a habitable zone further away than we thought, and how this would help us spot habitable planets more easily in the future. Today is the second news story this week dealing with finding planets, and it deals with more familiar Sun-like stars and their dusty planetary discs. Dust is both a good thing and a bad thing when looking for planets orbiting other stars. Dust tells us that there is a high likelihood of finding planets, but too much dust blocks out the planets that we look for. Warm dust is worse...
The seventh planet from the Sun is a boring one. The best photos we have of Uranus were obtained in January 1986 during the passing of Voyager 2, and they revealed a cold, pale-green, ball of Methane four times the diameter of Earth with very little visible activity. Since then, we’ve learned a lot about Uranus, and it’s far more interesting than we thought. It has rings, a magnetosphere, and numerous moons. It has a 98 degree axial tilt, meaning that the poles of the planet cycle through 42 years of sunlight and 42 years of darkness during it’s 84...
