Of all the planets in our solar system, Mercury might be the most underrated. It doesn’t have fancy swirling clouds or rings or plumes. It doesn’t even have an atmosphere. This little rocky body does have a history of volcanism, though, and even has water ice in its craters. Mercury is also locked into a special resonance with Jupiter (think of it like a billion year old dance partner), and there’s a chance many millions of years from now, that Mercury will lose its balance and get flung out of the solar system and maybe take Mars out on its way.
Just this week, our innermost planet got its moment of glory, when it executed a rare transit, passing in front of the sun in just the right alignment so people on Earth could view it. It won’t transit again until 2032. Only two spacecraft have ever visited l’il Mercury: Mariner 10 in 1974 and 1975 and NASA’s Messenger mission which orbited Mercury from 2011 to 2015 when it was deorbited and crashed into the surface. This week we’re going to get a bit more familiar with the solar system’s innermost world.
While you wait for the next Mercury transit, take a look at the rest of the collection of space photos here.