Colliding stars

I know that likelihood of stars colliding is very low, but have there been papers describing the theoretical process of star collision? James, London I think we can divide star-collision into three classes: Stellar Mergers Binary collisions Stellar Collision Under the stellar merger label we

All about the Asteroid Belt

What does it actually look like in the asteroid belt? Is it anything like as dense as is shown in films? Or is it more like you can see one or two rocks in the distance? Matthew, Amsterdam Contrary to popular belief, the asteroid belt

How big is the biggest galaxy in the Universe?

If by big we mean physical dimension, the largest known galaxy is most likely IC1101. IC1101 is gargantuan even among galaxies; it’s a super elliptical galaxy with a diffuse stellar halo that to extends to at least 1.4 million light years. The Milky Way’s halo by comparison

What’s the speed of Gravity?

For all intents and purposes gravity travels at the speed of light but it is very hard to measure, and so far we have no direct model-independent measurement of the speed of gravity. Physics has to main gravitational models: Newtonian dynamics and General Relativity The Newtonian

Stars of the Future

If the universe continues expanding forever, how long until it’s too diffused to allow star formation? How many generations of stars will that mean the universe has? How will the elemental make-up of these late stars be different and what effects will that have? I

Dark, seasonal flows emanate from bedrock exposures at Palikir Crater on Mars in this image from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. Image Credit: NASA/JPL-Caltech/Univ. of Arizona

Water flowing on Mars

NASA has announced that the Mars Reconnaissance Orbiter snapped some interesting photos that seem to indicate that water still flows on the surface of the red planet during the summer months. No water was directly detected but the presence of those long dark lines stretching from

Credit: Stephen van Vuuren

Something out of Nothing

If the 1st Law of Thermodynamics is true how could the Universe begin from nothing? To answer this question we need to remember that nothing is a global term and not a local one. Vacuum states exist where there is no matter or energy (they have maximum

Can anyone hear us?

Assuming that there are other intelligent civilisations out there in the universe, what is the likelihood that we’ll ever be able to communicate? The key to answer this question is to look at the Drake Equation. Where N is the number of civilisations in our