By Joe Diorio
March 2020 marks the 54th anniversary of the flight of Gemini 8, the 51st anniversary of Apollo 9, and in April we mark the 50th anniversary of Apollo 13.
OK, fess up. Unless you are a science and space nerd (like me), you didn’t know any of that did you?
Quick recap for the non-nerds in the audience: Gemini 8 and Apollo 9 were test flights in preparation for the July 1969 moon landing. Apollo 13 was a disaster in deep space and was chronicled in a Tom Hanks movie. Oh and, by the way, Neil Armstrong, who was the first person to walk on the moon, was the commander of Gemini 8.
Dates in the history of space flight may sometimes get lost in history, but space terms stick around in our language. Although they are not always used correctly.
As the anniversaries of those space milestones approach, and considering that prime star gazing begins in the Spring, I touched base with Janet Ivey, President of Explore Mars and CEO of the popular “Janet’s Planet” television science segments to straighten out some space terms that are frequently misused.
Dark Side of the Moon: Besides referring to a Pink Floyd album, there is a persistent misnomer that the moon has a completely dark side. Scientists refute that, pointing out that while the moon is “tidally locked,” meaning the same side always faces the Earth, that one side isn’t dark. It is farther than the side with the Sea of Tranquility on it, fueling the urban reference that something being on the far side of the moon is really far away.
While I’m at it, calling it a “sea” is a misnomer as well, although the genesis of that name doesn’t reside in NASA’s lap. The name was coined in 1651 by Francesco Grimaldi and his bestie Giovanni Battista Riccioli as they were doing some lunar cartography.
Anyhow, Merriam-Webster defines “sea” as a great body of saltwater, and Neil Armstrong didn’t find any saltwater when he visited. Which brings me to:
Search for water: The common misconception is that scientists are looking for a place to take a quick dip. It’s a little different in space. Water as a solid, liquid, or gas is in a lot of places – the poles of Mercury, Pluto, and the clouds of Venus all have traces of frozen water. It really isn’t a search as much as it is a categorization.
Weightlessness or zero-g: Gravity doesn’t go away once you are in space. Gravity is pulling at us all the time, albeit not by very much at 17,000 miles above the Earth. Rather than being weightless, in space you are in a constant state of freefall. The proximity of the celestial body that is pulling at you determines how fast you fall.
Twinkling stars: Yeah, it sounds romantic all right, but the proper term is astronomical scintillation, referring to what we see in the night sky. The twinkling – excuse me, scintillation – is caused by the Earth’s atmosphere, which is made up of different layers that have different temperatures, densities, and other variables that cause light coming from a star to bend and refract.
Falling or shooting star: To be blunt, there ain’t no such thing. Stars burn out. Sometimes they explode. But the streaks of light we sometimes see in the night sky are caused by tiny bits of dust and rock called meteroids that are falling into Earth’s atmosphere and are burning up. If any part of a meteoroid survives the fall and lands on Earth, it is called a meteorite.
Life: Yep this one gets confused, too. All of us are conditioned to think of life as we know it. But scientists looking into space think of life in purely agnostic terms, searching for biosignatures rather than E.T. waving at us as the Hubble Telescope peers into space.
Let’s boldly go and write carefully out there, people.
Joe Diorio is a writer living in Nashville, Tennessee. He’s more than happy to bore you to death with his meager astronomical prowess.