diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000000000000000000000000000000000000..f451386c21093b5115dc9d2d80d8fc7e206f3b29
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+*.dat
+results/
diff --git a/mars.txt b/mars.txt
index b36abfd5275517f9a3727a2201a562b2fd028993..93a3e13f245f8fed35ce8387dcc0e4613960691d 100644
--- a/mars.txt
+++ b/mars.txt
@@ -1,3 +1,4 @@
 Cold and dry, but everything is my favorite color
 The two moons may be a problem for Wolfman
 But the Mummy will appreciate the lack of humidity
+An ill-considered change