Why does Iapetus have two colours?

Iapetus is the third largest satellite of Saturn, and it is the largest object in the solar system not in hydrostatic equilibrium. Iapetus is a moon of Saturn known for its colour dichotomy. It has a dark side and white side, and it is often called the Yin Yang moon.

PodcAstroholic – Life On Other Planets

60 In this PodcAstroholic we talk about the likelihood of life on other planets

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...

Calories in anti-matter

Dear Mr Science Guy, How many calories would get in a bottle of antimatter? How long would it take to burn off at the gym if you drank it? Thank you, Rob, age 30 Rob asks a very...

Shopping for rings

I have a space question. I know about the Roche limit but is there an upper limit to how big a ring can get compared to its planet? Asked by Dan Of course there are limits, the Universe is all about limits! But they're not as strict as one would think. We have found an object in 2012, J1407b, with a ring system 200 million kilometres in diameter. If the rings were centred on Earth they would cover the inner solar system all the way to the orbit of Mercury on the opposite side of the Sun.
Credit: Wikicommon

Black Holes and Impossible Planets

Black holes are incredibly fascinating. They represent the unknown, the dangerous, the terrifyingly majestic. They are the modern version of the void, the abyss, the bottomless pit. Most sci-fi gets black holes right, but...

Has anyone got a recipe for artificial gravity?

One of the underlying ideas in Einstein's general relativity is that for an observer, the acceleration due to gravity, or the acceleration due to thrust, are identical. This is a consequence of the equivalence...

A Ghostly Cradle Of Stars

If you wonder where we came from and how we got here, there's a step we are quite confident on. About 5 billions of years ago, before the Sun shone a single ray all...

Do astronauts age faster or slower in space?

That is an excellent question, and the answer lies with the two theories of relativity: special and general.

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...