The Atacama desert is often compared to the surface of Mars. It’s barren landscape is eerily similar to the alien world, and as one of the driest regions on the planet it has very little in the way of plant life. When I visited the region this past June, the comparison was obvious. But this past year the Atacama has gotten more rainfall than usual. While still minuscule by most standards, it has entered Spring with landscape of wildflowers.
If someone’s only experience was to see the Atacama during its flowering period, a comparison to the surface of Mars would seem out of place. Which goes to show why observations over time are important. Landscapes can change dramatically over time, so one must be careful not to presume a single observation is representative.
The same is true in astronomy. One of the challenges is to make sure that we have a wide enough range of data to be truly representative. When we have limited data that can be difficult. For example, for centuries our solar system was the only one we knew. It made a certain sense that large gas planets would form in the outer region of a solar system and small rocky ones in the inner region. Our solar system seemed typical. But as we observed exoplanetary systems, we found our solar system to be more the exception than the rule.
We’ve also seen examples where astronomical objects were once thought to be radically different, but turned out to be similar phenomena. Quasars, blazars and radio galaxies have dramatically different appearances, but are in fact all powered by supermassive black holes.
This is why long term sky surveys are so important to modern astronomy. As we gather data on the whole sky over time, we can see how things change and evolve throughout the universe. And sometimes we discover something as wonderful as the flowers of Atacama.