13 Things to Know About DNA Testing Kits

iStock
iStock

The search for our identities—where we came from, what we're made of—is a unifying human experience, and our collective fascination with ourselves as individuals has fueled a booming industry around personal DNA testing. More than 12 million people have had their DNA tested by services like 23andMe and AncestryDNA, and that number is expected to grow substantially in the next few years. But can DNA tests really reveal the nuanced information about ancestry and health that many of us seek? Here are 13 things to know about these personal testing kits.

1. PERSONAL DNA TESTING IS SIMPLE—ALL IT TAKES IS A LITTLE SPIT.

Typically, all you have to do is collect some of your saliva or swab the inside of your cheek, then seal the sample in a container and mail it to the lab in a pre-labeled envelope or box. Six to eight weeks later, you can see the results online.

Most personal DNA tests are relatively affordable: Kits from industry leaders like 23andMe, AncestryDNA, Family Tree DNA, MyHeritage DNA, and Living DNA range from $69 to $199. In some cases, the price depends on which genetic reports a customer opts to receive: For 23andMe, for instance, a test that only aims to analyze your ancestry is cheaper than one that also includes health information. Check out this Wiki chart from the International Society of Genetic Genealogy to compare companies' offerings.

2. THE KITS LOOK FOR GENETIC VARIATIONS CALLED SINGLE NUCLEOTIDE POLYMORPHISMS.

After extracting DNA from your cheek swab or saliva sample, DNA testing companies search your DNA for certain genetic variants. The building blocks of DNA are chemical bases called nucleotides, which come in four varieties—A, T, C, and G (adenine, thymine, cytosine, and guanine, respectively). We have 3 billion pairs of these bases, so 6 billion letters in all, strung together in a sequence. Altogether, this genetic information is called your genome.

DNA testing companies determine which of the four letters is present at many locations in your genome. Much of the sequence is shared among humans, so the companies focus on specific letters that vary from person to person, known as single nucleotide polymorphisms (SNPs). Many SNPs have some biological relevance. For example, having one variant of a specific SNP near the gene OCA2, which codes for a protein believed to be involved in producing the dark pigment melanin, makes it much more likely you’ll have blue or green eyes. Other traits and even some diseases are also associated with certain SNPs, some more strongly than others.

3. KIT ACCURACY CAN VARY BASED ON TESTING METHODS.

According to company spokesperson Scott Hadly, 23andMe can identify SNPs with 99.9 percent accuracy, which is in a plausible range for the methods they use. Since many other major companies use similar techniques, their accuracy may be about equivalent—but not all tests meet the same standards. Recently, one test failed to recognize that a purportedly human DNA sample actually came from a golden retriever named Bailey. It did recommend, though, that based on her genetics, Bailey should take up cycling and basketball. The canine’s results came from the lighthearted Superhero DNA Test, which claims to tell customers about their strength, speed, and intelligence. It only tests for four genetic variants, while the pricier kits can include tens of thousands of variants. (It's also worth noting that no matter how many variants a kit tests for, it can't predict complex traits like intelligence, which are influenced by many different genes and environmental factors.)

You should steer clear of companies that offer dubious predictions about your optimal diet, what sports you'll be good at, and other questionable tips. Experts say using DNA tests to extrapolate this information is at best premature and at worst pseudoscience, especially because the recommendations are often based on just a handful of studies on specific groups of people, commonly white men. "The results that have been acquired in one population are not always generalizable to other populations," Jason Rosenbaum, an assistant professor at the University of Pennsylvania's medical school, tells Mental Floss.

4. DNA CAN REVEAL GENETIC CONNECTIONS—BUT INFORMATION ON SOME POPULATIONS IS LIMITED.

Companies use various methods to determine ancestry, but the tests generally involve comparing the customer's DNA to reference DNA meant to represent populations from different geographical regions. Since most people have at least somewhat mixed heritage, ancestry is often represented in percentages: 26 percent Polish, 14 percent Greek, and so on.

These tests aren’t able to guarantee where your ancestors actually lived—they can’t directly compare your data to DNA from people who lived hundreds of years ago, as Adam Rutherford, a British geneticist, pointed out to Gizmodo. And not all groups of people are equally represented in the reference populations, which can impact how precise your results are. People with European backgrounds are overrepresented in the reference data, while there are fewer references relevant to those whose roots lie in the Middle East or Asia, for example. But as research is done on a more diverse range of people, companies are tweaking their analyses to provide more detailed ancestry information to people from all over the world.

5. SOME HINT AT YOUR DNA'S DISTANT HISTORY—INCLUDING NEANDERTHAL HERITAGE.

All humans alive today can trace their mitochondrial lineage back to one woman nicknamed Mitochondrial Eve, who may have lived in Africa about 150,000–200,000 years ago (although this is a source of perennial debate). She wasn't the first modern human woman or the only woman living at the time; other women from her time also have descendants today. They just don’t have an unbroken line of female descendants like Mitochondrial Eve does.

We inherit our mitochondria—the parts of our cells that make energy—from our mothers. Some companies offer a mitochondrial DNA test that allows you to find your maternal haplogroup, which includes people who all share a maternal ancestor thousands or tens of thousands of years ago.

Men can learn about their paternal line through the Y chromosome, which is passed from father to son; certain SNPs on the Y chromosome can be used to determine a person's paternal haplogroup. (Women can find their paternal haplogroup through their biological father or brother.) There’s a "Y-chromosomal Adam," too, although scientists disagree about whether he lived around the same time as Mitochondrial Eve.

A home DNA test might even tell you that you're a little bit Neanderthal, which is especially common in Caucasian and Asian people. Don't worry about Neanderthals' reputation as dull brutes. We now know they were intelligent, used tools, and had their own complex culture.

6. YOU COULD FIND RELATIVES YOU DIDN'T KNOW YOU HAD.

Many DNA testing services allow customers to see whether other users of the same service are biologically related. This can be a boon for anyone assembling a detailed family tree, as well as any adoptees wondering about their biological families. Several people have discovered siblings they never knew they had through these services. In one case, two women—one adopted through an agency and another adopted by a family who found her in the woods as a baby—realized they were long-lost sisters.

Not everyone is pleased to uncover family secrets, though, and you should proceed with caution before you allow a company to match you with new relatives.

7. DNA TESTS CAN REVEAL HEALTH INFORMATION …

While genetic testing might reveal your inability to detect the unique odor of asparagus pee, most people are seeking deeper information, such as whether they have genetic variants associated with diseases like Alzheimer's or breast cancer.

Genetic risk is all about probability. For example, it may be frightening to learn you have an SNP associated with a tenfold increase in risk for a disease—but if that disease only affects 0.01 percent of people, your risk is still just 0.1 percent. Even if you have a SNP strongly associated with a more common illness and show signs of having it, you should see a doctor to get a proper evaluation.

And having a disease-associated SNP isn't a diagnosis. Rare variants are especially likely to lead to false positives: if a variant is only found in one in a million people, it’s more likely that the positive test result is an error than it would be with a more common variant. Some companies report on genetic variants that doctors and scientists haven't deemed medically useful to test for—which is why combing over every SNP is of dubious use. Shoumita Dasgupta, an associate professor in the biomedical genetics program at Boston University, tells Mental Floss that healthcare providers often don't order tests for these SNPs "because professionals have come to the conclusion that the predictive value of these tests is limited."

8. … INCLUDING YOUR RISK OF CERTAIN KINDS OF CANCER.

In March 2018, the FDA granted 23andMe permission to give customers information about certain mutations in the genes BRCA1 and BRCA2 that dramatically increase the risk for breast and ovarian cancer. Some people with a faulty BRCA gene take precautions to prevent or detect cancer early, including undergoing preventive double mastectomies, as Angelina Jolie famously did in 2013.

An important caveat: This test only screens for three SNPs in the BRCA genes that are connected to a dramatic increase in the risk of developing cancer. A positive result merits a consultation with doctor, but a negative result doesn't necessarily mean you're free from the risk of cancer, hereditary or not.

9. SOME DNA TESTING KITS ARE PRESCRIPTION ONLY.

GeneSight is designed to reveal what psychiatric medications will work best for a particular patient. Fertilome aims to show whether a person has genetic markers associated with increased risk of fertility problems, and is intended to help people make reproductive decisions such as whether to freeze eggs or try another round of in vitro fertilization. However, both Fertilome and GeneSight have faced criticism from experts who say there's not enough evidence that the tests are clinically valuable. They're also expensive: Fertilome costs $950, while GeneSight can cost several hundred dollars (though the price can drop to zero with certain insurance plans).

10. MORE DATA ISN'T ALWAYS BETTER.

With the price of DNA analysis falling rapidly, some companies are offering to analyze the order of all the letters of a customer's DNA—what's called sequencing—rather than just looking at SNPs. Sequencing is important in research and medicine: Dasgupta says she now sees some physicians ordering full sequences of multiple genes or even whole exomes (the protein-coding sequences in the genome) for patients.

Exome sequencing is useful to doctors and scientists because it allows them to look for genetic variants beyond the commonly tested SNPs. But every test has a risk of generating false positives, so excessive testing means an increased risk that a person will receive an incorrect diagnosis. Rosenbaum likens it to MRIs. "It's one reason why we don't just give MRIs to everyone, because you're going to turn up things that lead you to believe there's disease where there isn't disease," he explains.

11. YOUR DNA RESULTS COULD CONTRIBUTE TO RESEARCH.

Some home DNA testing companies ask customers to participate in research, answering questions about everything from their sleep habits to their personalities. The goal is to discover previously unknown associations between genetic variants and specific traits. "The way many genetic studies are designed, the more people who are recruited to the study, the more likely the study will be able to identify genetic factors that impact the trait or condition being studied," Dasgupta says.

Personal DNA testing companies potentially have access to the genetic data of millions of users, giving them a huge opportunity to make these connections. Using customer-provided data, 23andMe has already reported some preliminary discoveries on genetic variants linked to detached earlobes, the risk of Parkinson's disease, and more. Studies based on self-reported information always come with caveats, but they’re common in many fields of research and especially useful when collecting objective data isn't practical or possible. Future research spurred by these observations will reveal whether crowdsourced research like 23andMe's has potential to become part of geneticists' repertoire.

12. YOU COULD POTENTIALLY EARN MONEY FROM YOUR DNA.

One company, Genos, charges $499 to sequence a customer's entire exome, and then offers to connect them with genetic researchers. Participating research partners can offer $50 to $250 to Genos users for completing a study intended to find links between their genetic information and any trait or condition the researchers are studying, including dementia, cancer, and infectious disease. Meanwhile, the newly formed company Nebula proposes to sequence customers' genomes, secure them with blockchain technology, and allow customers to control the data—including selling it to biotech and pharmaceutical companies in exchange for Bitcoin-like cryptocurrency. There’s still potential for privacy issues, however, since there’s no guarantee companies that rent or purchase genetic data will keep it secure.

13. YOUR DNA MIGHT ONE DAY HELP TO CATCH A CRIMINAL.

Recently, police investigators in California arrested a man suspected to be the Golden State Killer, thought to be responsible for dozens of rapes and burglaries and at least 12 murders in California from 1976 to 1986. The suspect left DNA behind at the scene of a 1980 murder; after having the DNA analyzed, the investigators created a fake profile on the genealogy website GEDMatch and uploaded the data, hoping it would turn up some of the killer's relatives. It did—and with the help of genealogy experts, the investigators followed the genetic trail to the Sacramento home of 72-year-old Joseph James DeAngelo, who was a cop during the first several years of the deadly crime spree.

The case has raised ethical and privacy concerns for some experts. Genetic data can be stored indefinitely, and it’s possible to use a person's DNA to make inferences about biological relatives who haven’t even taken DNA tests.

One Good Reason Not to Hold in a Fart: It Could Leak Out of Your Mouth

iStock/grinvalds
iStock/grinvalds

The next time you hold in a fart for fear of being heard by polite company, just remember this: It could leak out of your mouth instead of your butt. Writing on The Conversation, University of Newcastle nutrition and dietetics professor Clare Collins explains that pent-up gas can pass through your gut wall and get reabsorbed into your circulation. It's then released when you exhale, whether you like it or not.

“Holding on too long means the build up of intestinal gas will eventually escape via an uncontrollable fart,” Collins writes. In this case, the fart comes out of the wrong end. Talk about potty mouth.

A few brave scientists have investigated the phenomenon of flatulence. In one study, 10 healthy volunteers were fed half a can of baked beans in addition to their regular diets and given a rectal catheter to measure their farts over a 24-hour period. Although it was a small sample, the results were still telling. Men and women let loose the same amount of gas, and the average number of “flatus episodes” (a single fart, or series of farts) during that period was eight. Another study of 10 people found that high-fiber diets led to fewer but bigger farts, and a third study found that gases containing sulphur are the culprit of the world’s stinkiest farts. Two judges were tapped to rate the odor intensity of each toot, and we can only hope that they made it out alive.

Scientific literature also seems to support Collins’s advice to “let it go.” A 2010 paper on “Methane and the gastrointestinal tract” says methane, hydrogen sulfide, and other gases that are produced in the intestinal tract are mostly eliminated from the body via the anus or “expelled from the lungs.” Holding it in can lead to belching, flatulence, bloating, and pain. And in some severe cases, pouches can form along the wall of the colon and get infected, causing diverticulitis.

So go ahead and let it rip, just like nature intended—but maybe try to find an empty room first.

[h/t CBS Philadelphia]

17 Facts About the Apollo Program

NASA/Getty Images
NASA/Getty Images

NASA was officially established in October 1958. Just two years later, the agency started what would become one of the defining programs of the 20th century—Apollo, which put humans on the Moon in 1969. In honor of NASA's 60th anniversary, and the upcoming 50th anniversary of the Moon landing, here are 17 facts about the Apollo program.

1. THE NAME DOESN’T HAVE DEEP ROOTS.

When NASA and the Space Task Group were brainstorming names for their first manned satellite project, they favored “Project Astronaut,” which they believed would “emphasize the man in the satellite.” According to NASA, that name was eventually discarded “because it might lead to overemphasis on the personality of the man.” Mercury was chosen instead: Thanks to its use in thermometers and automobile branding, it was familiar to the American public. The Roman god's role as a messenger was also appealing [PDF]. The program would go on to make six manned flights between 1961 and 1963, taking us from Alan Shepard’s 15-minute flight to L. Gordon Cooper’s 34 hours in space.

As NASA began looking beyond Mercury missions, they recognized that a mythological naming convention had been established. Dr. Abe Silverstein, NASA's director of space flight programs, suggested the Greco-Roman god Apollo—which might seem like an odd choice for a lunar program, considering Apollo is traditionally associated with the Sun rather than the Moon. But Silverstein supposedly felt that the image of “Apollo riding his chariot across the Sun was appropriate to the grand scale of the proposed program.”

According to The New York Times, however, Silverstein would later say there was “No specific reason for it ... It was just an attractive name.”

2. APOLLO WASN’T ORIGINALLY SUPPOSED TO TAKE US TO THE MOON’S SURFACE.

The original intent of the program wasn't actually a lunar landing. When it was announced in 1960, Project Apollo’s goal was to send a three-man crew to orbit the Moon, not land on it. It wasn’t until May 1961 that President John F. Kennedy delivered his famous speech declaring that “this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the Moon and returning him safely to the Earth.”

It was an ambitious plan: At the time Kennedy made his announcement, only two people had ever been in space. In addition to Soviet cosmonaut Yuri Gagarin in April 1961, and Alan Shepard a month later, other animals that had made it to space included fruit flies, monkeys, dogs, and a chimpanzee.

3. APOLLO 2 AND 3 DIDN’T EXIST.

In 1967, astronauts Virgil Grissom, Edward White, and Roger Chaffee were conducting a preflight test—where the command module was mounted as it would be for a launch, but nothing was fueled up—for what was known as mission AS-204 when a fire broke out, killing the three astronauts. The decision was made to honor the astronauts by referring to the never-completed flight as Apollo 1—but this left open the question of what to call the next flight.

One solution was to call the next flight Apollo 2. Another option proposed was to retroactively designate three earlier flights (AS-201, 202, and 203) as Apollo 1-A, Apollo 2, and Apollo 3, even though these flights launched before the fire. The reason for the suggestion wasn't evident even to NASA. As the agency explained, “the sequence of, and reasoning behind, mission designations has never been really clear to anyone.”

Eventually, according to NASA’s history, the never-launched flight “would be officially recorded as Apollo 1, ‘first manned Apollo Saturn flight—failed on ground test.’ AS-201, AS-202, and AS-203 would not be renumbered in the ‘Apollo’ series, and the next mission would be Apollo 4.”

4. THE LAUNCH OF APOLLO 4 WAS ONE OF THE LOUDEST MAN-MADE NOISES EVER.

The control room for the launch of Apollo 4.
Keystone/Getty Images

Apollo 4—an unmanned mission that served as a test of the 363-foot-tall Saturn V rocket—was the first ever launch at NASA's Kennedy Space Center in Florida, when it occurred on November 9, 1967. The liftoff was so loud (according to NASA, one of the loudest manmade noises ever) that it shook buildings as far as three miles away, causing dust and debris to fall from the ceiling of the control center (above). "I hope the Vehicle Assembly Building (VAB) doesn't get any cracks," Dr. Hans Greune, director of Kennedy Launch Vehicle Operations, said after the launch. "It rattled pretty hard and a cheer went up in the control room after liftoff." The launchpad lacked a sound suppression system—but by the time the Space Shuttle was in use, more than 300,000 gallons of water were sprayed out in just 41 seconds to dampen its sound to acceptable levels.

The mission, which was successful, was designed to test the structural and thermal integrity of the craft and to evaluate various support facilities.

5. APOLLO 5 WAS A SUCCESS; APOLLO 6, NOT SO MUCH.

The uncrewed Apollo 5 was designed to test the operation of the lunar module, and it was mostly a success (there were concerns with the water boiler temperature). Apollo 6 was also unmanned, but had many more issues. For 30 seconds it experienced something called the “pogo effect” (which Popular Science explains is “almost like the rocket is bouncing on a pogo stick”)—something that NASA pointed out “would have been very uncomfortable for any crew.” Then two of the engines shut down, and the third stage wouldn't restart. Despite all these setbacks, Apollo 6 never made national headlines. On the day of the disastrous flight, Martin Luther King. Jr. was assassinated in Tennessee. “About the only explaining that NASA had to do, therefore, was to the congressional committees on space activities, who seemed satisfied with what they heard,” NASA explains.

6. THE PROGRAM RECEIVED AN EMMY.

Apollo 7 was a mission of firsts: It marked the first Apollo mission that sent people to space, as well as the first live television transmissions from space. During the transmissions—which were called the “Wally, Walt, and Donn Show”—astronauts Walter Schirra, R. Walter Cunningham, and Donn Eisele gave a tour of the vehicle and cracked a few jokes. Schirra even commented that he was “going to try for an Emmy for the best weekly series,” to which the ground crew responded, “I thought you were going to try for a Hammy” [PDF].

In a way, Schirra did get his wish: In 1969, Apollos 7, 8, 9, and 10—all of which made broadcasts back to Earth—received a special Trustees Award from the National Academy of Television Arts and Sciences.

7. APOLLO 8 GOT NASA SUED.

On Christmas Eve 1968, Apollo 8 astronauts Frank Borman, Jim Lovell, and Bill Anders circled the Moon and snapped the famous Earthrise photo. They were also told to do “something appropriate” to honor the event for the millions who were listening to them. They decided to recite from Genesis. "It's a foundation of Christianity, Judaism and Islam," Lovell said of the choice. "They all had that basis of the Old Testament."

Famous atheist Madalyn Murray O’Hair—sometimes referred to as “the most hated woman in America”—sued, alleging her First Amendment rights had been violated. Ultimately, the judge dismissed the suit and the Supreme Court declined to hear it due to lack of jurisdiction. But it did have an effect on later missions—according to Buzz Aldrin’s memoirs, he had intended to read a communion passage back to Earth during Apollo 11, but at the last moment was asked not to because of Apollo 8’s legal challenges.

8. THE FLAGS ON THE MOON HAVE A COMPLEX STORY.

Buzz Aldrin poses next to an American flag on the surface of the Moon.
NASA/Liaison/Getty Images

Raising the American flag on the Moon turned out to be a controversial move. In his 1969 inaugural address, President Nixon had proclaimed that we should “go to the new worlds together—not as new worlds to be conquered, but as a new adventure to be shared.” That spirit of shared exploration led some at NASA to discuss putting a United Nations flag on the Moon. At the same time, some had concerns over the visual effect of planting an American flag on the Moon, which they believed could make it look like the Americans were taking control of the Moon (which would have been a violation of the Outer Space Treaty). Eventually, however, the committee decided to plant the American flag and also leave a plaque to emphasize that they “came in peace for all mankind.”

The flag debate would be settled in no uncertain terms later in 1969, when NASA’s appropriation bill proclaimed “the flag of the United States, and no other flag, shall be implanted or otherwise placed on the surface of the Moon, or on the surface of any planet, by the members of the crew of any spacecraft making a lunar or planetary landing as a part of a mission under the Apollo program or as a part of a mission under any subsequent program, the funds for which are provided entirely by the Government of the United States.” Mindful of the Outer Space Treaty, the bill made sure to note that “This act is intended as a symbolic gesture of national pride in achievement and is not to be construed as a declaration of national appropriation by claim of sovereignty.”

9. IT’S UNCLEAR WHERE THE APOLLO 11 FLAG CAME FROM.

There are two possible sources for the Apollo 11 flag—and neither of them involve anything high-tech. Originally, NASA proclaimed that the “Stars and Stripes to be deployed on the Moon was purchased along with several others made by different manufacturers” in Houston-area stores. When it was affixed to the pole and crossbar that would be planted in the Moon dust, all labels and identifying information were removed.

Not long after the Moon landing, according to a NASA Contractor Report on the Lunar Flag, the head of flag manufacturer Annin & Co. asked if the flag was one of theirs. He was told that "three secretaries had been sent out to buy 3x5-foot nylon flags during their lunch hours. After they had returned it was discovered that all of them had purchased their flags at Sears."

Annin was the official flag supplier to Sears, but not wanting “another Tang”—a reference to the free publicity Tang received from NASA after John Glenn drank an orange liquid from a pouch on Friendship 7—they refused to confirm the manufacturer.

Jack Kinzler, a NASA executive, was unable to verify any of this information, though; his notes suggest that the flag was purchased from the Government Stock Catalog for $5.50.

10. BUZZ ALDRIN HAD TO FILL OUT AN EXPENSE REPORT FOR HIS TRIP.

Even a guy on the work trip of a lifetime had to fill out some paperwork afterward: Once he was back on Earth, post-successful moonwalk, Aldrin filed a travel voucher totaling $33.31. "To: Cape Kennedy, Fla. Moon Pacific Ocean (USN Hornet)," it read.

11. APOLLO 12 WAS STRUCK BY LIGHTNING—TWICE—AFTER LIFTOFF.

Astronauts Pete Conrad, Richard F Gordon Jnr, and Alan L Bean getting ready to go to the moon on the Apollo 12 mission.
Hulton Archive/Getty Images

Just 36 seconds after liftoff on November 14, 1969, the astronauts on Apollo 12—Alan Bean, Charles "Pete" Conrad, and Richard Gordon, Jr.—felt something strange. Then, things began to go wrong. The craft had been struck by lightning twice, at 36 seconds after takeoff and again at 52 seconds. Though no one in the crew or on the ground realized what had happened, the three men were calm and waited it out. Bean would later say that “One of the rules of space flight is you don't make any switch-a-roos with that electrical system unless you've got a good idea why you're doing it. I knew we had power, so I didn't want to make any changes. I figured we could fly into orbit just like that.” Eventually, he reset the electrical systems, and after 25 minutes, those systems and the fuel cells were back up and running. But the crew still had to fire its main engine to leave Earth's orbit and head for the Moon—and the automated navigation was busted. Gordon used a sextant, and Bean broke out a star chart to help them figure out where to go. And they made it.

The next Apollo mission may be the most famous, besides 11, because of its own problems—and an oxygen tank intended for Apollo 10 (Apollo 13’s Jim Lovell would later congratulate the Apollo 10 crew for getting rid of it). The tank, 10024X-TA0009, was one of two set for the earlier Apollo mission, but problems with pumps meant all the tanks needed modification. In the removal of this particular tank, it caught on a bolt and fell two inches—but because it was felt that no damage occurred, everyone moved on, and the tank was installed in the spacecraft soon to be known as Apollo 13.

During testing before the flight, technicians noted that the tank had difficulties emptying. To boil off the remaining liquid oxygen the electric heater inside the tank was plugged into 65-volt power for eight hours, with the nearby wires being subjected to 1000°F temperatures. It would later be discovered that using 65-volt power severely damaged the tank’s thermostatic switches, which were designed for 28 volts (NASA explains that in 1965, the permissible voltage to the heaters was raised to 65 volts, but the thermostatic switch manufacturer never got the memo). This internal damage likely resulted in a spark that destroyed the tank, leading to the legendary saying "Houston, we've had a problem” [PDF] and, in 1995, an award-winning movie.

12. APOLLO 12 MIGHT HAVE FOUND MICROBES ON THE MOON ... OR MAYBE NOT.

When Apollo 12 landed on the Moon, it was right next to the lander from 1967’s Surveyor 3. The astronauts grabbed parts from the craft—including a camera—to study the effects of years on the lunar surface.

Researchers hadn’t sterilized Surveyor 3, and when the camera was opened in a clean room back on Earth, a small colony of Streptococcus mitis was discovered. These bacteria had apparently survived almost three years without nutrients in freezing space and the finding, which frequently gets discussed on the internet, was hailed as a remarkable discovery.

Sadly, researchers have recently returned to the Surveyor 3 camera and learned that the claim was, at best, unconvincing. One problem was that the people studying the camera were wearing short sleeves, meaning post-recovery contamination was a very real possibility—though the researchers caution “proving the truth in such a situation is difficult, if not impossible” [PDF].

Microbes or no, there's still an important takeaway from the situation: It demonstrated the potential issues that could arise with future samples returning from places like Mars.

13. APOLLO 15 TOOK A VEHICLE TO THE MOON.

Apollo 15 Astronaut James Irwin on the moon with a moon buggy.
Keystone/Getty Images

Apollo 15, the fourth mission to put human boots on the Moon, brought along a first-of-its-kind, 460-Earth-pound Lunar Rover Vehicle (LRV) that was about the size of a dune buggy. Astronauts David Scott and James Irwin became the first people to drive on the surface of another world, and the LRV—which had a top speed of 8 mph—allowed them to travel farther from their landing site than any previous astronauts. "The LRV on Apollo fulfilled a very important need, which was to be able to cover large traverses, carry more samples, and get more scientific exploration done," Mike Neufeld, a senior curator at the Smithsonian National Air and Space Museum in Washington, D.C., told SPACE.com in 2011. "It was a really important part of why Apollo 15, 16, and 17 were so much more scientifically advanced and productive." Scott and Irwin traveled around 17 miles in the LRV. The design of the vehicles—and their experiences on the Moon—helped inform the design of the rovers that went to Mars.

14. ONE APOLLO ASTRONAUT HAD A REACTION TO LUNAR REGOLITH.

Of the 12 men who have walked on the Moon, geologist Harrison Schmitt was the only scientist. He had a reaction to lunar regolith, or Moon dust. Schmitt said the dust caused “a lot of irritation to my sinuses and nostrils soon after taking the helmet off ... the dust really bothered my eyes and throat. I was tasting it and eating it.” He joked that he had “lunar dust hay fever.” Apollo 17 would go on to collect 741 rock and soil samples—more than any other Apollo mission.

15. THE APOLLO ASTRONAUTS HAD VARIED JOBS BACK HOME.

The post-space careers of the Apollo astronauts is varied—Michael Collins was the first director of the National Air and Space Museum, for instance. Harrison Schmitt became a senator from New Mexico. James B. Irwin founded an evangelical organization, while Edgar Mitchell researched psychic phenomenon.

But the astronaut to have the most interesting job post-Moonwalk might be Buzz Aldrin, who told CNN, “Most people who have received a degree of public recognition find themselves financially pretty well off. Doesn't happen to be the case with astronauts.” And so he found himself working for a Cadillac dealership in Beverly Hills—though by his own admission he wasn’t very good at it. He explained in his memoir Magnificent Desolation, “I was a terrible salesman ... People came onto the lot in search of a car, and as soon as I struck up a conversation with them, the subject immediately turned from the comfort and convenience of a new or used luxury automobile to space travel. I spent more time signing autographs than anything else ... In fact, I didn’t sell a single car the entire time I worked at [the dealer].”

16. AN EXPERIMENT LEFT ON THE MOON DURING THE APOLLO MISSIONS IS STILL ONGOING.

One of the most lasting contributions of Apollo 11 was a 2-foot-wide panel consisting of 100 mirrors. Similar objects were left by Apollos 14 and 15, as well as Soviet rovers. Called the Lunar Laser Ranging Retroreflector experiment, it is "the only Apollo experiment that is still returning data from the Moon,” according to the Lunar and Planetary Institute. The experiment works by shooting a laser at the mirror and waiting for the reflection—but as anyone who has shined a laser pointer knows, while they don’t disperse as much as other light sources, lasers still disperse. In the case of the Moon, the laser is 4.3 miles in diameter when it hits the Moon, and 12.4 miles wide when it returns to Earth. But thanks to the program we’ve been able to learn that the Moon is moving roughly 1.5 inches away from the Earth every year, and gain new insights into Einstein’s Theory of General Relativity.

17. NEARLY HALF A CENTURY AFTER THE FINAL APOLLO MISSION, HUMAN EXPLORATION STILL MATTERS.

It’s often said that we’ve never returned to the Moon after Apollo. That’s not quite true—in 2016, China’s Yutu rover ceased operations after spending 31 months on the Moon. But humans haven’t returned, and that may be a problem.

In 2012, Ian Crawford of Birkbeck College London wrote a paper arguing that human space travel has its benefits over robotic exploration. For one, “human missions like Apollo are between two and three orders of magnitude more efficient in performing exploration tasks than robotic missions, while being only one to two orders of magnitude more expensive” [PDF]. The paper also points out that missions like Apollo are funded and undertaken for a wide range of sociopolitical reasons, and humanity can benefit in many ways.

Not everyone is convinced. Some critics argue that autonomous robots, with their rapidly improving abilities, are the better option. It’s a question with serious implications for the future of space exploration.

SECTIONS

arrow
LIVE SMARTER