Some New InSight

Yesterday the NASA InSight mission successfully touched down on Mars. While it was the eighth NASA mission to reach the red planet's surface, it was the first in a few new categories: first mission to send information via cubesat orbiters, first mission to deploy instruments by itself upon reaching the surface, the first mission to launch from the west coast of the United States, and the first mission to drill into another planet. Sure, all those things sound cool, but why should we care?

Celebrations in the mission control room at JPL in Pasadena, CA after
confirmation of InSight's successful landing came through.

First, a bit of backstory. Every NASA mission that has flown in the past decade has been the winner in a multi-stage selection contest that NASA administrators run. We'll go into more detail in a later post since the process is fairly intricate, but the basics are that many missions submit their plans to a NASA request for proposals, then some of those are selected to move on and create prototypes and more precise mission plans, and from those only one mission is selected. The InSight mission was initially one of 28 mission proposals submitted to NASA in 2010. In May 2011, it became one of three selected from the whole pool to develop more details about the mission and begin some work on building and testing instruments. In August 2012, just days after the Curiosity lander successfully landed on Mars, the InSight mission was selected for development and flight.

InSight uses updated versions of technology that was first included on the Phoenix Mars lander, which successfully landed on Mars a decade ago (2008). To reduce the risks of future missions, NASA likes to select missions that make use of any instrument or mission piece that has already flown on a mission and worked. These missions components are called heritage pieces because they have been inherited down to a newer mission from an older one. The instruments are never exactly the same, even if scientists and engineers want them to be--manufacturers discontinue electronics, technologies improve, etc. Engineers are responsible for extensively testing every single mechanical aspect of the mission in a number of ways--extreme heat, extreme cold, and high radiation are only a few of the environmental factors that a space mission will experience in its lifetime. Of course, the instruments must not only survive, they need to work too, and it's much better to work out issues ahead of time than after launch.

Testing the robotic arm that will deploy the SEIS
instrument. Photo credit: NASA/JPL/Caltech

The seismometer on InSight is a good example of when extensive testing uncovered a problem that could have jeopardized the whole mission. The Seismic Experiment for Interior Structure (SEIS) instrument was built by the French National Space Agency CNES, and will be responsible for obtaining seismic data of Mars, which is effectively the reason that this mission was selected in the first place. Without it, the mission will not be able to collect any seismic information of Mars. Clearly, it was a key part of the mission. During testing, the engineers discovered multiple small leaks in its vacuum chamber that actually holds the seismometer. The leaks were severe enough that the mission's launch date was pushed back from March 2016 to May 2018. The overall cost of this delay was great in both time and money; it cost roughly $150 million to redesign the vacuum chamber, rebuild it, retest it, and pay for the time of the people who worked on it.

InSight launched on May 5, 2018 from Vandenberg Air Force Base in California, a location on the coast in between San Francisco and Los Angeles. Most NASA missions launch from Cape Canaveral in Florida, though some launch from the Wallops Island Flight Facility in Maryland, so InSight is unusual in this regard. Vandenberg was selected because of its good positioning to aim the spacecraft to enter the Mars atmosphere at the correct angle of 12 degrees. Any steeper and the mission would burn up. Any shallower and the mission would "bounce" off the top of the atmosphere and continue off into deep space, lost forever. It was 12 degrees, or failure. If anything, this illustrates to me that there are many precise calculations that go into making every single decision on a NASA mission, and one miscalculation could cost the whole mission.

After 6 months and 301 million miles, InSight finally entered Mars' atmosphere at a perfect 12 degree angle. Much has been written and said about what happened during the landing, so we'll point you to one of our favorites instead of rehashing it here. In about 3 month InSight will deploy its own instruments, including the seismometer and an instrument that will drill 16 feet down into Mars' crust to study the thermal environment of Mars beneath the surface.

A screenshot of the NASA InSight landing live-feed on November 26, 2018, showing the first picture InSight took of Mars' surface. The line in the background is the Martian horizon. The camera lens is still behind the dust cap in this image,  but that piece will be removed in a couple of days, after the dust settles.

Just to prove that it made it to the surface, InSight was programmed to take a couple of pictures at the surface and send them back to us here on Earth. Its relay system is the Mars Cube One (MarCO), an important first for this mission as well. MarCO are two 6U cube sat missions that was designed to relay messages back and forth between Earth and InSight on Mars while it was going through its landing process. What is a cube sat? Generally the larger a mission is, the more expensive it is. A cube sat is a mission that is roughly the size of a shoebox, and it's a type of mission that has become more popular in the past 5 years because they are small, quick and easy to build, and inexpensive. A "U" is a shorthand to refer to the size of a cube sat mission, where a U is a cube with 10 cm sides. A 6U cube sat, therefore, is one that is 30 cm long, 20 cm wide, and 10 cm tall. MarCO was a test to see how well cube sats would work in a deep space environment, one that it passed with flying colors. This will pave the way for future cube sat add-on components to larger missions and even individual cube sat missions (see LunaH-Map here).

All of these accomplishments were the results of years of hard work by its team members and the mission failures that happened before. We thank all the scientists and engineers who have study and do study Mars, and all the people who support them, and wish them all many congratulations! Here's to future breakthroughs on Mars!

Thanksgiving Plants

Last week we told you all about the domestication of the chicken-peacock, a.k.a. the turkey. Since there will be many vegetables present on Thanksgiving tables this week, it's only fair to talk about them too! Here are the histories of some of the most popular plants that we love to eat (or love to hate, we don't judge)!

Sweet potatoes, baked and delicious. Photo from: Food Network

Sweet potatoes: Ipomoea batatas, or the sweet potato, was first domesticated somewhere between the Orinoco River delta area of modern day Venezuela and the Yucatán Peninsula in Mexico around 5,000 years ago. The second name of the sweet potato, batata, is the original Taíno word for the plant, though the Quechua people in Peru call it kumar. Surprisingly, it is only distantly related to the white potato, and is a genetically different plant from a true yam. In fact, the sweet potato is fairly closely related to the morning glory flowers, and the flowers of a sweet potato plant are even called tuberous morning glories! As with most of the plants on this list, it was first introduced to Europe via Spanish conquistadors, and to China via Portuguese traders. Sweet potatoes were used around the world to supplement the lack of other food due to poor harvests or other natural events. For example, after the sweet potato was introduced to Japan in the early 1600s, it became an important plant that prevented starvation in years when the rice harvest was poor. It is a popular plant because it grows well and without pesticides in a variety of climates, though it will not survive the cold and requires roughly 36 inches of water a year to grow.

The Three Sisters plants. Image from:
University of Illinois Extension

Squashes and pumpkins: The domestication of squashes and pumpkins (all part of the genus Cucurbita) is one of the best known stories, and one of the oldest: there is archaeological evidence that puts the domestication of squashes before 10,000 years ago! The wild relatives of squashes produce fruit much smaller than what we know today, and the plants were bitter, even toxic. Only the intense domestication efforts of the indigenous people in Central America saved the squashes we enjoy today. These plants are highly adaptable, and grow in many diverse climates. The reason there are so many types is because they have been traded and transported around the world to many different places, and these plants needed to adapt to survive in their new habitats. The English word squash comes from the Naragansett word askutasquash (a green thing eaten raw), excellent evidence that the plant was able to adapt from its Mesoamerican origins to survive in Rhode Island!

An important point is that squash, beans, and corn are called the Three Sisters of plant husbandry because they are mutually beneficial organisms. Basically, they help each other grow so well that the native peoples in the Americas often planted the three of them together! Squash was the first of the Three Sisters to be domesticated, followed by corn and beans.

Corn: Corn was domesticated from maize by the indigenous peoples roughly 10,000 years ago in what is now southern Mexico. The word "maize" comes from the Spanish version of the original Taíno word for it: mahiz. While the consensus used to be that the Tehuacán Valley was the center of domestication, newer analyses show that the the nearby Balsas River Valley is the true origin point of what we know as corn. A study in 2002 showed that modern corn comes from a single domestication event of maize at least 9,000 years ago, and other studies put this date even earlier. Another study argued that knowledge of corn cultivation was spread through two different events thousands of years apart: one event spread corn cultivation down the Andes Mountains around 6,700 years ago, and the second event spread it across the rest of South America roughly 2,000 years ago. It was taken back to Europe by Spanish conquistadors, and quickly became a popular plant around the world because of its ability to grow in many climates, but it is very sensitive to cold and to droughts, and strong winds can uproot it because of its shallow root structure. Today there are many forms of corn, though most of them are grown for industrial purposes (corn ethanol, animal food, etc.).

Beans: Unlike other plants on this list, beans were known in Europe and around the world before any Spaniard set food on the American continents. The beans that are part of the Three Sisters, however, were originally domesticated in (as you may have guessed) Central America. Some bean remains in the Guitarrero Cave in Peru date beans there to 4,000 years ago, though genetic analysis has proved that those beans were merely cultivated there. Beans, along with corn and squash, gradually spread south as knowledge of their cultivation also spread. Beans need support as they grow, and growing them near corn stalks provided that support. Beans in return pull nitrogen from the air and put it in the ground for corn and squash to use. They grow best in the summer and with lots of water. Currently the genetic information for 40,000 species of beans are held in genebanks, but only 30 of those are actually eaten.

Cranberries on a bush. Photo from: FastGrowingTrees.com

Cranberries: Cranberries were domesticated very recently, only about 200 years ago in Cape Cod, Massachusetts. Before then they were wild plants that the Native Americans would collect and use in a variety of different ways, from preserving fish and meat to mixing them into a poultice to use on wounds. Because the cranberry is a relatively young domesticated plant, it hasn't changed much from its wild variety. Cranberries are closely related to blackberries, huckleberries, and the flower rhododendron (that part blows my mind), and distantly related to the fruits kiwi and persimmon. Most cranberries today are grown in the United States, specifically Massachusetts, Wisconsin, New Jersey, Oregon, and Washington, though they are also grown in five provinces in Canada, and parts of Europe and Chile. They are tough plants but do best in wet, cold regions. Cranberries also are high in polyphenolic antioxidants and have some anti-cancer properties. So, eat up!

We here at Science on Main wish you a very happy Thanksgiving, and thank you for reading!

Sources:
 Zhang, D.P.; Ghislain, M.; Huaman, Z.; Cervantes, J.C.; Carey, E.E. (1999). AFLP Assessment of Sweetpotato Genetic Diversity in Four Tropical American Regions (PDF). : International Potato Center (CIP) Program report 1997-1998. Lima, Peru: International Potato Center (CIP). 
 http://bioweb.uwlax.edu/bio203/2011/keesler_cole/
https://www.sciencedirect.com/science/article/pii/S1055790317301811 
https://www.smithsonianmag.com/smart-news/domestication-saved-pumpkin-and-squash-180957314/
"Origin, History and Uses of Corn". Iowa State University, Department of Agronomy. February 11, 2014.
Piperno, Dolores R. (2011). "The Origins of Plant Cultivation and Domestication in the New World Tropics: Patterns, Process, and New Developments". Current Anthropology. 52 (S4): 453–S470. 
Bitocchi, Elena; Nanni, Laura; Bellucci, Elisa; Rossi, Monica; Giardini, Alessandro; Zeuli, Pierluigi Spagnoletti; Logozzo, Giuseppina; Stougaard, Jens; McClean, Phillip; Attene, Giovanna; Papa, Roberto (3 April 2012). "Mesoamerican origin of the common bean (Phaseolus vulgaris L.) is revealed by sequence data". Proceedings of the National Academy of Sciences. 109 (14): E788–E796. 
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4076063/
 

Turkey Tale

Soon, families in the United States will sit down around a table to consume a famous dish: the Thanksgiving Turkey. According to a study done by the National Turkey Federation (yes, it's a real thing), 88% of Americans eat turkey on Thanksgiving, which amounts to around 46 million turkeys every year for Thanksgiving alone. Turkey has become more popular as an alternative to red meat in recent years as more varieties of turkey burgers, sausage, and cold cuts are added to supermarkets, not to mention all the dishes you could make with leftover turkey after Thanksgiving! Yet how much do you really know about that bird on your plate?

Gobble gobble! What a beautiful bird. Photo from:
http://jacksbbq.com/home/turkey/

Turkeys are native to North America, mainly the vast area east of the Rocky Mountains and some parts of central Mexico. There are two species of turkey in North America: the familiar Meleagris gallopavo and the slightly-less-common ocellated turkey, Meleagris ocellata, which can only be found in Mexico's Yucatán Peninsula. The wild and domesticated turkeys belong to the same species, M. gallopavo, whose name literally means "chicken peacock." There are also five different subspecies of turkey that are found in different places of the United States, Mexico, and Canada: the eastern wild turkey, the Osceola (Florida) wild turkey, the Rio Grande wild turkey, Merriam's wild turkey, and Gould's wild turkey. 

Turkeys were first domesticated by the indigenous people of central Mexico in the modern-day states of Jalisco, Guerrera, and Veracruz around 2000 years ago. The birds were an excellent food source in both their meat and their eggs, and their feathers were used in decorations. Perhaps because of its silly appearance and perceived personality, the turkey was associated with the Aztec trickster god, Tezcatlipoca, a central deity of Aztec religion. New DNA analysis of turkey bones from the southwest United States suggest that a second, separate domestication event took place between 200 BCE and 500 CE. The evidence suggests that these turkeys lived in civilizations that were in central Arizona and New Mexico around and on the Colorado Plateau, which strongly implies that these animals were specifically bred by people instead of naturally migrating north from Mexico.

A ceramic whistle that looks like a turkey, from the Colima
shaft tomb culture in Jalisco, Mexico. 300 BCE–400 CE.

After the Spanish landed in the New World, they took some of the animals back with them to Europe.
The name turkey probably came from some of the birds coming into British ports via ships that traveled from the eastern Mediterranean Sea. They were incorrectly associated with the African guinea fowl, whose name back in the 1500s was the turkey cock, which was thought to have come originally from the country of Turkey. From there, the name stuck, and persists to the modern day. As a result of selective breeding in Europe, there are now many different varieties of turkeys, all part of the same original species. All of the domesticated turkeys today come from the original population that was domesticated in central Mexico thousands of years ago.

The names used to describe turkeys themselves are quite silly. Males are called toms, and females are called hens, which are actually normal names for birds. The two names for the young are rather odd though: poults and turkeylings (the best name I've ever heard for baby animals). The red pieces of flesh on the beak of the toms also have names. The flesh that connects to the bottom of the beak is called the wattle, and the flesh that connects to the top of the beak is called the snood. The average size of a turkey is 29.8 pounds and 3.5 feet long, but the largest turkey weighed 86 pounds and was 4.1 feet long!

An adorable turkeyling!
Photo by Kristie Gianopulos.

Finally, as you go to break the wishbone of the turkey after the meal, remember that the scientific name of that bone is the furcula, the "little fork" in Latin. The furcula is an ancient bone that is present in some theropod dinosaurs (think Velociraptor and Tyrannosaurus), which was used as evidence to show how birds are modern dinosaurs. Furcula in birds are used to anchor the muscles that power the wings and help the birds to fly, but in domesticated turkeys, those muscles aren't really needed. Two people breaking the bone as a sign of good luck is a tradition that dates back to the 1600s, though it was not called officially called a wishbone until 1860.

Personally, the most interesting thing I knew about turkeys before today was that Benjamin Franklin once thought they should have been the national bird instead of the bald eagle. Knowing what I know now, I have to agree with him: the turkey deserves a lot more attention than as a centerpiece once a year. Thank you for reading!

Sources:
http://extension.illinois.edu/turkey/turkey_facts.cfm
http://www.nwtf.org/hunt/article/wild-turkey-subspecies
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2840336/ <--Turkey DNA study
Webster's II New College Dictionary. Houghton Mifflin Harcourt 2005, ISBN 978-0-618-39601-6, p. 1217

November update

Thank you, readers, for your patience! Unfortunately there will not be an article this week, as the author's car got a flat tire and she spent all of her normal writing time fixing that. Part of being in grad school is making choices about how to spend time, and she needs to spend her work week on the stuff that will actually help her graduate.

There are at least three article topics lined up already for you, one of which will involve input directly from an outside source. We'll see you back here on Monday!