The last few weeks have been exciting for anyone who loves space. We celebrated the 50th anniversary of the first mission to orbit the moon, Apollo 8. The New Horizons probe explored Ultima Thule, an object in the Kuiper belt and now the subject of the most distant photograph ever sent from space. Finally, the Chinese space agency landed a rover on the far side of the moon for the first time in history.
All of these missions were, in some way, about investigating our origins. Apollo 8 may not be as famous as Apollo 11, which actually landed on the moon, but it perhaps was more daring. No one had left low earth orbit before the flight and there was real concern the astronauts wouldn’t come home if everything didn’t go according to plan.
Apollo 8 went to the moon, but in a sense discovered the earth, resulting in the famous picture, “Earthrise”. As the spacecraft orbited the lunar surface on Christmas Eve, the astronauts read the first verses of Genesis describing the formation of the world. Few could hear those words and not marvel on the majesty of creation.
New Horizons is searching for evidence of the creation of our solar system by doing a flyby of Ultima Thule, a primordial body left undisturbed from billions of years ago. Scientists have not created time machines, but they have other ways of looking into the distant past, whether by taking ice core samples on earth or looking through telescopes at the edges of the universe. New Horizons is studying an object that looks much the same as it did at the foundation of our solar system.
But the mission is not without controversy. The name Ultima Thule is a Latin phrase for a distant place, quite appropriate for an object that lies a billion miles past Pluto. The problem is that Nazis have used the term to refer to a mythic Aryan land. Should an important celestial body have a name with such a connotation? The lead scientist for New Horizon’s response was succinct: “just because some bad guys once liked that term, we’re not going to let them hijack it.”
China’s Chang’e 4 mission to the far side of the moon will investigate the origins of our companion. How did it form and why does it look the way it does? The far side of the moon is never seen from Earth, so it presents logistical challenges for exploration, but it is not always dark. In fact this week it is bathed in sunlight as we on earth experience the new moon. On Monday we celebrated Rosh Hodesh Shevat, the first day of the Hebrew month when no moon can be seen in the sky while on the far side it was high noon.
One “day” on the moon is 28 days: two weeks of daylight and two weeks of nighttime. The only difference between the near and far side is that the former sees the Earth hanging in the sky (with its own phases) and the latter does not. The Chinese Yutu 2 rover had to take a “noon nap” during this time because of the dangerous extreme high temperatures and will have to do the same around lunar midnight because of the extreme cold.
As science further expands outward to new undiscovered corners of our universe, we learn more and more about who we are and where we came from. Hopefully we continue to be in awe of the beauty, fragility and importance of nature.