Big stars tend to stick together. They all require incredibly dense regions in which to form, but once they do, they do a great job of blowing away and ionizing any other gas and dust in the vicinity. This is why nebulas in distant galaxies are great tracers of massive star formation. The bigger and hotter the star, the more UV light it produces, the more it ionized a gas cloud, the more we see gorgeous nebula. So it’s no surprise that when I look at the nebula below, I can guess that the central stars are huge, outweighing our...
Gamma rays are the most powerful form of electromagnetic radiation in the universe. With wavelengths as small at atoms, they usually result from the most powerful interactions known, such as the collision of two particles, or the release of energy from the accretion disk of a black hole. But there is another potential source of gamma rays that has not yet been confirmed: Dark Matter. The leading candidate for dark matter is the theorized Weakly Interacting Massive Particle (WIMP), though it is not as wimpy as its namesake suggests, making up 5 times as much mass as the visible matter...
A few days ago I wrote about a galaxy that was tough to see because of Milky Way field stars. But our galaxy is far more than just a bunch of stars smattered about. There is also a huge amount of gas and dust with varying temperatures. Some of the hotter and more illuminated gas and dust are what make nebulae so lovely in space. But the cold gas and dark dust that is just out floating in the cold interstellar medium? That stuff gets in the way. A normal image of interacting galaxies M81 and M82 would try to hide the...
Welcome to a new series of posts that will characterize 1000 amazing facts about the Universe. There is so much out there that we have yet to learn, and every day, astronomers across the globe are using their research to reveal the deepest secrets of the cosmos. This series will look at the strangest, coolest, most exciting facts that we have discovered in hundreds of years of modern science. Fact #4: Most of the stars in the universe are red dwarfs smaller than our Sun. There is a leap of understanding that happens when a child learns that our Sun...
Remember the big picture of Andromeda that showed 100 Million stars? That image resulted in a ton of new galaxy discoveries. Most of these new galaxies were once hidden beyond the Andromeda galaxy, but with the super high resolution image, astronomers and the public were able to look straight through and see far more distant objects. Most images of galaxies have what we call ‘field stars’ in them. These are some of the 400 Billion stars of the Milky Way that are far closer than the galaxy we are imaging. For this reason, galaxy images tend to look very cluttered...
There are many types of objects in space that just can’t be seen with visible light, and many more that have very different features when observed across the electromagnetic spectrum. A prime example of the former is a molecular cloud. Cold, incredibly huge, and full of low density Hydrogen, these clouds are the raw material for star forming galaxies. If stars begin to form within them, they can be seen as gorgeous nebulae, but when alone in the darkness of space we need to look for the dim signature of radio waves they emit. The Smith cloud, named after it’s...
This week marks the 12 year anniversary of the Spirit and Opportunity rovers, part of the Mars Exploration Rover (MER) mission. Only expected to last 90 days, Opportunity is still working. Not only functional, it’s still returning good data about Mars. It’s definitely taken a beating, and it has to be careful. Being powered by solar panels and not a thermonuclear generator like it’s younger cousin Curiosity means it has to be careful to stay in the sunlight. Dust on the panels certainly reduces their efficiency, but Opportunity has had some help from Martian winds to keep the dust from...
The elements that make up our world and our selves, where do they come from? Sure there is plenty of Oxygen in the air, Silicon and Carbon are just lying around, and a bunch of other stuff can be found across our planet. but where did they come from originally? We know that most of the elements are synthesized within stars, but which ones aren’t? Which ones are made in a lab? The Big Bang gave rise to the first elements Hydrogen and Helium, which eventually clumped together to form the first stars and star producing the heavier stuff. Lithium,...
The big dipper is visible every day of the year from the Northern Hemisphere. It’s easily recognizable and most people have spotted it at least once in their life. But most people also assume that it is just a boring collection of stars where nothing interesting ever happens. The big dipper is so much more than a simple spoon in the sky, especially right now. The well-known asterism, part of the much larger Ursa Major constellation, is home to many visible deep-sky objects, though right now it is visited by the comet C/2013 US10 Catalina, close to the visible binary...
When were the planets discovered? Uranus and Neptune were definitely not found until modern science began, since a telescope was required to see them. The other five planets were not actually discovered per se. Since they are visible to human eyes, they have been observed since prehistoric times, and we see examples of cultures across the ancient world who observed them. The five visible planets are Mercury, Venus, Mars, Jupiter, and Saturn. Starting this weekend, you can see them all across one part of the sky, a visual alignment that hasn’t occurred since 2005. Planets are so-named because of the Greek...
