The Minor Planet Centre has just announced that the Earth has been orbited by a second moon for the past three years or so. But while excitement about the discovery is growing, it is important to keep in mind that this moon isn’t as impressive as our main satellite.
Most space missions investigate the surface or atmosphere of a body. But NASA’s InSight probe, which landed on Mars in November 2018, is different – it is the first mission dedicated to studying the interior structure of the planet and whether it gives rise to “marsquakes”.
Just over a year ago, courtesy of NASA’s New Horizons mission, we were treated to images of 2014MU69, a small object 6.6 billion kilometers from the sun – making it the most distant object to have ever been visited by a spacecraft.