I once ordered a beer then straight away spilled it all over the bar. There was just a tiny sip left in the glass. Frowny face.

Remember ‘Oumuamua, the weird-shaped rock flying through the Solar System? Just like my sip of beer, it might only be a small piece of what it once was. … More ‘Oumuamua: a shred of its former self

In Rendezvous with Rama (by Arthur C. Clarke), a mysterious object is discovered passing through the Solar System.  The object has a strange shape — it’s a giant cylinder.  It was discovered by the Spaceguard survey, designed to find objects that might impact Earth (so-called near-Earth objects).  Spoiler alert: the cylinder is a spaceship sent … More A cigar from another star

The asteroids may be cosmic refugees, ejected from their homes to wander the Solar System, eventually settling in the asteroid belt. … More The asteroid belt: a cosmic refugee camp?

Imagine a dry Earth. No waterfalls. No oceans. No beer (or people to drink it).  A sad place. Water is pretty important stuff.  In this post we will go deep into how Earth got its water (much deeper than in this post from a while back).  And since it’s connected with how Earth formed, our … More Where did Earth’s (and the asteroid belt’s) water come from?

At a Solar System party, in a room full of planets, the asteroid belt is full of angst. And it should be. It’s out of place. It’s wearing a clown outfit but it’s not a costume party. What makes the asteroid belt so different? Well, for one, it’s not just one object like each individual … More The chaotic teenage Solar System

This post could also be titled: How blogging and social media help make science happen. Here is the story.  Planet Nine was conjectured in late January 2016. In February 2016 I started to think about where Planet Nine may have come from. This led to 3 blog posts, each exploring a different origins story for … More Planet Nine from Outer Space!

It is hard to know where things come from. If I drink a Belgian-style beer brewed in Colorado using hops from Washington state and I live in France, where did the beer actually come from?  And what does that mean anyway? The cosmic situation is just as confusing.  We know where the planets are right … More Did the Solar System form inside-out?

We are discussing the origins of Planet Nine.  In part 1 we explored whether it could have been produced during an orbital instability in the early Solar System.  In part 2 we showed that Planet Nine could have been captured from another star.  Here we will explore another plausible idea that is a little less … More Planet Nine: Solar System renegade?

We are discussing the origins of Planet Nine.  In part 1 we explored whether it could have been produced during an orbital instability in the early Solar System.  Here we will explore a much more exotic origin. Scenario 2.  Planet Nine is a planet that formed around another star and was captured by the Sun … More Planet Nine: an intruder among us?