You may have noticed that our favorite red planet, Mars, has been a popular feature in the news recently. Not that we need any special reasons to take a closer look at Mars, but a number of coincident events have brought this about:
 Mars has just passed through opposition, or the point in its orbit where it is closest to Earth throughout the year—see Figure 1. This particular opposition brings Mars closer to Earth than it has been in 15 years.
 As a result of being closer to the Sun and having more atmospheric energy, Mars has been experiencing a severe dust storm that has grown over the last two months to envelop nearly the entire planet.
 As if this wasn’t enough, scientists also recently announced the discovery of an underground liquid water lake below the southern polar cap of Mars!
Figure 1Mars at opposition. The average distance from Earth to Mars is about 140 million miles (225 million km). The closest known approach was in August 2003 at 34.8 million miles (56 million km). On July 27, 2018 the distance from Earth to Mars was about 37 million miles (59 million km).
While we’re not announcing ...