On June 25th 1998 the Solar and Heliospheric Observatory known as SOHO, a small spacecraft that monitors the sun, went missing. An error in the instructions given to it from ground control left it spinning out of control. However, there is a glimmer of hope.

Since we first wrote about the Goldbach Conjecture we've had many requests for more information about  it and about how our Goldbach calculator works. We answer some of your questions here but the Goldbach conjecture touches on a strange area of maths that may leave you even more curious than before...

Testing times

• What's in a name?
• Disaster

We know there is infinitely many primes, but are there infinitely many twin primes?