With the success of the recent European Space Agency (ESA) mission to land on Comet 67P/Churyumov–Gerasimenko, we’ve started thinking more about the solar system and our place in it. Let’s take a look at interstellar maps!
Rosetta, Philae, and “Remarkable” Comets
The ESA launched a spacecraft with a lander—Rosetta and Philae, respectively—to Comet 67P/C-G more than 10 years before they actually made contact. In order to land on a 2-mile wide object approximately 317 million miles away, the mission needed exceptionally accurate math based on profoundly detailed maps. How advanced are our maps of the solar system? Which ones do we have access to through IU?
Broadly speaking, there are two types of maps for objects in space: ones of individual objects, and ones that show their position relative to other objects.
Maps that show relative position have been around for as long as people have drawn charts of constellations. In 1747, Emanuel Bowen mapped out “The Solar System, with the orbits of 5 remarkable comets.” His map shows the orbits of the planets out to Saturn (sorry Uranus, Neptune, and dwarf planet Pluto), plus the trajectories of 5 comets.
Is “remarkable” a scientific term?
Although not all the comets listed are named, Bowen includes the year of their appearance, as well as information about their distance from Earth and period if known.
Maps of individual bodies are much more recent, as the technology necessary is still advancing. In order to decide where Philae should land, ESA’s scientists started making a preliminary map of Comet 67P/C-G soon after Rosetta approached Comet 67P/C-G. This map outlines morphological regions, different portions of the object with distinct terrain such as cliffs, craters, and boulder-strewn fields.
If you’d like to see some of the process of determining this map, NASA’s Jet Propulsion Laboratory has an excellent set of images with highly informative descriptions that reveals some of the modelling process as Rosetta neared Comet 67P/C-G.
To trace the circuitous route Rosetta took on its way to its interstellar rendezvous, Where is Rosetta? provides an excellent interactive map. You can rotate the view to see the comet’s orbit in three dimensions, as its flight isn’t exactly parallel to Earth’s. The map can also help you realize why Rosetta traveled 6,563,230,000 km in order to meet a comet 515,789,500 km away.
Asteroid Maps, Near and Far
Rosetta isn’t the only mission to investigate and map objects in our solar system. In 2011 and 2012, NASA’s Dawn spacecraft observed the asteroid Vesta, which lies in the main asteroid belt between Mars and Jupiter. It took a team of 14 scientists about two and a half years to complete the mapping, which was based on observations made between June 2011 and September 2012. Dawn should reach Ceres, a dwarf planet in the same asteroid belt, in March 2015. Hopefully more maps will follow soon after that! Here’s a link to the article in the journal Icarus via ScienceDirect, if you want more scholarly detail than the news blurb provides.
Geologic Map of the Av-15 Rhealsilvia Quadrangle of Asteroid Vest
Frighteningly, asteroids don’t always remain millions of miles away from Earth. Smaller bits often make contact with our planet, as this recent map of asteroids in Earth’s atmosphere between 1994 and 2013 shows A new near-Earth object enters our atmosphere about once every other week, the data show, although not all of the smallest ones are depicted on this map.
Many of these new maps will be published in the relevant journals, such as those available through ScienceDirect. You can always head to IUCAT if you’re interested in finding other types of material as well. Here’s a link to the results of a search for “solar system maps” if you want to explore more.
Post by Ryan Randall