"This is the closest we've come, so far, to identifying a place with some of the ingredients needed for a habitable environment. These results demonstrate the interconnected nature of NASA's science missions that are getting us closer to answering whether we are indeed alone or not," commented Dr. Thomas Zurbuchen in an April 13, 2017 NASA Press Release. Dr. Zurbuchen is associate administrator for NASA's Science Mission Directorate at Headquarters in Washington D.C.
The moon's orbit. The moon's orbit is not on the same plane as the earth's orbit around the sun. If it were, every time we had a new moon we would have a solar eclipse, and every time we had a full moon we would have a lunar eclipse. Instead, the moon travels in a track that goes well above and well below the earth. Still, on occasion it will travel in between the sun and the earth and in this case, there will be an eclipse.
You might ask the situation of the other nations which also possess space technology. Especially, Russia has made some advancements of her own, but the Russian space program is only a fraction of what it once was. Of course, there is also some work by the Chinese as well as by the Indians and even the Europeans are trying to develop new space programs.