Crater Science Reaches New Depths at Chicxulub, Ground Zero for the End of the Dinosaurs

If there was ever any doubt whether an asteroid impact killed off the dinosaurs, field scientists continue to bring back proof from ongoing research in the Gulf of Mexico.
Last week, geologists working in the Yucatán Peninsula reached a major milestone in an offshore drilling project of the Chicxulub Crater, now known to be the remnant of a 66-million-year-old collision of a gargantuan asteroid into the Earth’s surface. Reaching a depth of 670 meters (2,198 feet) in the crater’s peak ring for the first time, the scientists brought up core samples of the original granite bedrock that occurred as a result of this Earth-shattering impact.

Discovered in 1978 by geophysicists Antonio Camargo and Glen Penfield, the crater has been the subject of study and controversy for some time, but this is the first time scientists have dug this deep offshore, into the inner ring of the double-ringed crater. From the core samples, taken from below 66 million years of sediment piled onto the original molten rock formed at the time of the impact, paleontologists now have a completely new data set to study the earliest moments of Earth after the Cretaceous.

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Wikipedia

With this evidence, we can now put to rest a point of contention regarding the exact border between the Cretaceous and the next age in the life of the Earth, the Paleogene, known as the K-Pg boundary. Prior to this project, paleontologists defined the K-Pg boundary with the appearance of foraminifera, fossils of small shelled creatures. In a sense, the drilling project took science back in time through rock layers never before investigated and passed the K-Pg boundary at ground zero. Because this layer of ancient rock is so thick and and so unique, the drilling team is considering re-naming it the “event layer.”

This news highlights a great number of phenomena in both natural history and astrophyics. Astronomers have studied peak rings in craters on the moon, Mars and Mercury, but never before on our own planet. The Chicxulub now offers a local opportunity to study this type of supermassive impact.

Apparently, peak rings form in a matter of minutes when an asteroid is so big, its impact liquefies rock, causing the center of the crater, while it’s in motion, to splash upward in a cone shape like a drop of water into a filled sink. This molten rock creates a distinct layer of minerals that only form from asteroid collisions. As the team continues to bore deeper, now working more slowly to study this unique type of rock, they will search for rock layers “out of order,” testing a proposed model for this type of impact. Theories state when these impacts occur, older rock layers are tossed above younger rock layers.

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Wikipedia

The discovery of Chicxulub is a fascinating story in itself, and shows how difficult this thing was to find. Essentially, the crater is so old, the only evidence of it is a trough that forms a faint semi-circle on the western portion of the Yucatán Peninsula and a system of thousands of cenotes, sinkholes formed as a result of the impact. (We’re still unable to explain why.)

Prospecting for oil drilling sites for the Mexican oil company Petróleos Mexicanos (Pemex), Penfield noticed a huge underwater arc 40 miles across in his geophysical data. He found another arc on land years later. Penmex suppressed specific data to the public, but allowed Penfield and Camargo to present the findings at the Society of Exploration Geophysicists conference in 1981, which was poorly attended.

In 1980, unaware of Penfield’s discovery, Alan R. Hildebrand, a graduate student at the University of Arizona, published the first paper proposing the Earth-impact theory and was searching for a probable crater. He and his team found evidence of an impact in shocked quartz, a type of deformed quartz created by intense pressure and limited temperature (the conditions of an impact crater), and tektites, beads of glass shaped like drops of water that form when molten rock is ejected into the atmosphere. Both of these materials occur in large deposits in the Caribbean basin.

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Wikipedia

Carlos Byars, reporting for the Houston Chronicle in 1990, connected the dots between Hildebrand’s theory and Penfield’s discovery, and Hildebrand and Penfield obtained Penmex drill samples stored in New Orleans for Hildebrand’s team to study. The samples matched Hildebrand’s theories.

Further research into the crater in the late 1990s using gravitational anomaly imaging showed the crater is a system of two concentric circles, the outer circle measuring 190 miles in diameter, nearly five times the diameter of the inner circle.

Personally, as a Texan, a Houstonian and a dinosaur nerd, I take pride in these developments. 1. The Chicxulub crater was discovered by a Mexican oil company. 2. A Houston reporter identified the crater as the one that killed the dinosaurs. Two points for Texas, a state steeped in petroleum science and Mexican culture.

For a grandiose, and slightly terrifying, example of how an asteroid impact can change the face of the Earth (the Chicxulub crater was created by a much smaller asteroid), watch this Discovery Channel simulation set to Pink Floyd’s “Us and Them.”

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This Mother’s Day, Honor Her with Color and Music at the HMNS Processional of Guadalupanas

by Ruth Cañas

Mother’s Day is a celebration honoring the mother of the family, motherhood, maternal bonds, and the influence of mothers in society.

The modern American holiday of Mother’s Day was first celebrated in 1908, when Anna Jarvis held a memorial for her mother at St. Andrew’s Methodist Church in Grafton, W.V. Following her mother’s death in 1905, Anna Jarvis conceived of Mother’s Day as a way of honoring the sacrifices mothers made for their children. Her mother had been a peace activist who cared for wounded soldiers on both sides of the American Civil War and created Mother’s Day Work Clubs to address public health issues. Jarvis wanted to honor her mother by continuing the work she started and to set aside a day to honor all mothers.

In 1914, President Woodrow Wilson signed a proclamation designating Mother’s Day as a national holiday to honor mothers, held on the second Sunday in May. This year, Mother’s Day is Sunday, May 8.

CEREMONIAL CUSTOMS

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Courtesy Niall Crotty

While Mother’s Day is celebrated throughout the world, traditions vary depending on the country. In Ethiopia, families gather each fall to sing songs and eat a large feast as part of Antrosht, a multi-day celebration honoring motherhood. Thailand celebrates Mother’s Day in August on the birthday of the current queen, Sirikit. In the United States, Mother’s Day continues to be celebrated by presenting flowers, cards and other gifts. Mexico celebrates Mother’s Day on May 10. Flowers are a must, and the day is also filled with music, food, celebrations, and often a morning serenade of the song “Las Mañanitas” from mariachi singers.

THE MOTHER OF MEXICO, EMPRESS OF THE AMERICAS

“Am I not here, I, who am your Mother? Are you not under my shadow and protection? Am I not the source of your joy? Are you not in the hollow of my mantle, in the crossing of my arms? Do you need anything more? Let nothing else worry you, disturb you.”

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Wikimedia

In 1531, Mary appeared to San Juan Diego, a humble indigenous farmer and laborer, at Tepeyac near modern-day Mexico City and asked him to build a church in her honor at the top of Tepeyac Hill, the site of a former Aztec temple dedicated to the goddess Tonantzin. She miraculously left her image on his tilma (a type of cloak), which he presented to the Spanish archbishop as proof of her request which is still on display at the Basílica de Guadalupe, one of the most-visited shrines in the world. Since then, the image of Our Lady of Guadalupe has been a symbol of faith, unity and mercy for people all over the world.

COMMEMORATING MOTHERS

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Courtesy Michele Whisenhunt

Sunday, May 8, the Houston Museum of Natural Science is celebrating Mother’s Day and honoring the Virgen of Guadalupe with a special evening Guadalupan procession with the Our Lady of Guadalupe Association Archdiocese of Galveston-Houston. As president, Pablo Guzmán was instrumental in creating an event that is bound to delight audiences of all ages. One of the most fascinating aspects of the Guadalupan procession is the cross-cultural mix of pagan and religious influences featuring elements that demonstrate the great love and devotion for the Empress of the Americas.

Joyous music including everything from mariachis to drummers to singing groups dressed in white and brass bands.

Bearers of bannersicons, treasure, homemade art, statues and other eye-catching items.

Scents provided by flower bearers, censers of incense, and roses.

Skilled performers, such as indigenous dancers known as matachines, marchers, and folk dancers.

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Courtesy Michele Whisenhunt

Special costumes of revelers dressed in Aztec regalia, adorned with feather headdresses and rattles on their ankles, carrying drums or feather shields. Girls dressed to imitate the Virgin of Guadalupe, many wearing red and green attire to resemble the flag of Mexico where Our Lady of Guadalupe appeared to St. Juan Diego.

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Courtesy Michele Whisenhunt

We hope you will join us in honoring motherhood with a spectacular experience! Click here to buy your tickets or call 713.639.4629.

FURTHER READING:

History of Mother’s Day

Mother’s Day Celebrations Around the World

Our Lady of Guadalupe

San Juan Diego

Words Spoken by Mary at Guadalupe

Editor’s Note: Ruth is Program Manager in the Adult Education department of the Houston Museum of Natural Science.

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Seeing Stars with James Wooten: Exciting Rare Mercury Transit Next Monday!

May Starmap

Jupiter is now high in the south at dusk. It outshines all stars we ever see at night, so you can’t miss it.

Mars and Saturn become late evening objects this month. Tonight, May 2, Mars rises in the southeast at 9:48 p.m. while Saturn comes up soon afterwards, at 10:24 p.m. By May 15, though, both planets rise during twilight, and on Memorial Day both are in the southeastern sky as soon as it gets dark. Mars and Saturn are still above the distinctive pattern of Scorpius, the scorpion. As you watch them rise, Mars is to the upper right and is much brighter.

In fact, this month, Mars outshines all of the stars and even rivals Jupiter in brightness! That’s because on May 22, Earth passes between the Sun and Mars. That alignment is called ‘opposition’ because it puts Mars opposite the Sun in our sky, making Mars visible literally all night long. It also makes Mars much brighter than normal in the sky, since we’re as close to it as we’ll ever get until Earth overtakes Mars again in 2018. Saturn comes to opposition June 3.

Venus is lost in the Sun’s glare and out of sight all month.

A swath of brilliant winter stars sets in the west at dusk. Orion, the Hunter, is still visible in the west as May begins. His two dogs, represented by Sirius and Procyon, are to his left.  Gemini, the Twins, are above Orion. The Big Dipper is above the North Star, with its handle pointing to the right. From that handle, you can ‘arc to Arcturus’ and then ‘speed on to Spica’; those stars are high in the east and in the south, respectively, at dusk. Leo, the Lion, passes almost overhead at dusk.

As Orion and his dogs set, look for Antares, the brightest star in Scorpius, the Scorpion, to rise in the southeast. Saturn and Mars will rise with the Scorpion’s head, above Antares. At the same time, Vega, brightest star of the Summer Triangle, appears low in the northeast. These stars remind us that summer is on the way.

Moon Phases

Moon Phases in May 2016:

New: May 6, 2:30 p.m.

First Quarter: May 13, 12:02 p.m.

Full: May 21, 4:14 p.m.

Last Quarter: May 29, 7:12 a.m.

Mercury Transit:

On Monday, May 9, 2016, Mercury overtakes Earth on its much faster orbit. This time, though, when Mercury passes Earth, the alignment is almost exact, such that Mercury appears in silhouette against the sun’s disk. This event is known as a transit of Mercury. Keep in mind that the planets are almost, but not exactly, in the same plane. Indeed, Mercury’s orbit is the most inclined — tilted up to 7 degrees from Earth’s orbital plane. That’s why Mercury does not usually transit the sun when it overtakes Earth. Monday’s event is therefore rare and special, occurring only 14 times in the 21st century (the next one occurs Nov. 11, 2019).

Transit_of_Mercury_May_9_2016_path_across_sun

Thus, weather permitting, the Houston Museum of Natural Science has arranged for volunteers from local astronomy clubs to set up solar telescopes outside our museum’s main entrance, near the sundial, to show you the transit. Mercury, already in the sun’s disk by sunrise in Houston, takes until 1:42 p.m. to cross to the other side of the sun’s disk. If skies cooperate, we’ll observe the transit from 10 a.m. until 1:42 p.m. on Monday, May 9. If there are sunspots on the sun’s disk while Mercury is there, Mercury will stand out because its disk is fully round and because Mercury moves noticeably across the sun’s disk during the hours we’re watching.

We will observe the sun (and Mercury in silhouette) through telescopes with filters especially designed to filter the sun safely, and by projecting the sun’s image onto a screen. These are the only two ways to observe the Sun safely. Please do not try to observe the sun directly or through an unfiltered telescope, as this will lead to permanent eye damage or blindness. Our common sense tells us this because we always avert our eyes when we accidentally turn towards the Sun. When something cool happens on the sun, some of us try to override our common sense, and there is no reason to do so. Come observe safely with us.

On most clear Saturday nights at the George Observatory, you can hear me do live star tours on the observation deck with a green laser pointer. As of now, George is closed which Brazos Bend State Park dries out from last month’s floods, and is scheduled to reopen May 10. If you’re there, listen for my announcement. 

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Mark Your Calendars for these events happening at HMNS 5/2-5/8

Last week’s featured #HMNSBlockParty creation is by Dylan (age: 9):

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Want to get your engineering handwork featured? Drop by our Block Party interactive play area and try your own hand building a gravity-defying masterpiece. Tag your photos with #HMNSBlockParty.

Cultural Feast – Amazonian Culinary Adventure
Wednesday, May 4
7:00 p.m.
During the 16th century, Spanish and Portuguese explorers searching for gold and other valuable commodities in the Amazon often suffered from food shortages. They had little or no interest in the exotic flora on which the native population thrived. With more scientific exploration by scholars beginning in the 18th century, the value of many of the native Amazonian plants and trees was soon recognized, as reflected in their impact on industry, medicine and cuisine. Chef David Cordúa will create innovative dishes featuring ingredients native to the Amazon, while culinary historian Merrianne Timko places the edible Amazon in historical context.

Cabinet of Curiosities opens Friday, May 6
As an homage to its own history, the Houston Museum of Natural Science will be presenting an interpretation of the cabinet of curiosity. Visitors will have the unique opportunity to peruse various objects of curiosity and wonder, up close and in a personal way.

Class – Virgen de Guadalupe Procession
Sunday, May 8
6:30 p.m.
The vibrant troupes of the Archdiocese of Galveston-Houston’s Our Lady of Guadalupe Association will perform a special Mother’s Day procession in honor of the Holy Mother with music, dancing, elaborate costumes and Aztec feather headdresses. Live commentary will describe the symbolism unique to each troupe and traditions of Guadalupana processions.

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