Planetary poetry

The inspiration for this blog—the 'Golden disk' on Voyager—is not the only example of a human message sent out on an interplanetary journey. The early days of space exploration were filled with declarations from us humans here on Earth. For instance, both Pioneer 10 and Pioneer 11 in the early 1970s (sent to explore the outer planets and leave the solar system) featured gold-anodized aluminium plaques designed by Carl Sagan. These plaques show illustrations of nude men and women to represent the human race, as well as other information, in case the spacecrafts were ever intercepted by extraterrestrial life.

Carl Sagan holding the Pioneer plaque. Credit: www.daviddarling.info

Apollo 11—probably the most famous space mission of all—included a plaque that was bolted onto the lower part of the Eagle Lunar Module. This landing stage still sits on the Moon and can even be seen in modern-day Lunar Reconaissance Orbiter Camera images.

The landing stage of Apollo 11's Eagle Lunar Module can still be seen in images from NASA's Lunar Reconnaissance Orbiter Camera. The flight hardware is at the centre of this image, with its shadow to the left. Credit: NASA/GSFC/Arizona State University

The Apollo 11 plaque reads as follows:

Here Men from the Planet Earth First Set Foot Upon the Moon

July 1969 A.D.

We Came in Peace for all Mankind

Apollo 11 plaque attached to the ladder of the Lunar Module. Credit: NASA

But another, much less formal, but equally enduring and touching message was left also on the Moon by the astronaut Gene Cernan. Cernan was the commander of Apollo 17 and the last man—to date—to have walked on the Moon. He writes in his autobiography of the small way in which he honoured his daughter during his final moments on the lunar surface:

"... I drove the Rover about a mile away from the LM [Lunar Module] and parked it carefully so the television camera could photograph our takeoff the next day. As I dismounted, I took a moment to kneel and with a single finger, scratched Tracy's initials, T D C, in the lunar dust, knowing those three letters would remain there undisturbed for more years than anyone could imagine."

Just this week, NASA's MAVEN (Mars Atmosphere and Volatile EvolutioN) spacecraft has entered into orbit around Mars. This mission will be the first to study the upper atmosphere of the Red Planet, and how it has evolved with time. As part of the mission's education and public outreach activities, the University of Colorado ran a public competition. In this contest, people young and old were invited to write a haiku that could be sent along with the poet's name onboard MAVEN to Mars. This type of programme is a great way to inspire children to think about science—and poetry—and I even submitted an entry myself.

MAVEN, you raven

pray, tell, with your expert ways

is Mars life's haven?

This was actually my first attempt at haiku, and I thought not a bad first effort. It even gained the approval of my talented poet friend who had first brought the competition to my attention. Unfortunately, however, it didn't make the final cut. The winners can be read here, and my favourite is probably this one by Greg Pruett:

distant red planet

the dreams of earth beings flow

we will someday roam

I haven't picked a piece of Earth today to represent our planet to unknown aliens, but these poems, plaques, and traced initials are all beautiful examples of the ways in which we humans try to communicate our place in the universe. As MAVEN starts its orbital mission, I hope it succeeds in unraveling some of Mars' atmospheric mysteries. Perhaps we will learn if our planetary neighbour could ever have supported intelligent life, and what caused its evolution to diverge so drastically from that of our own Earth.

Artist's conception of the MAVEN spacecraft in orbit around Mars. Credit: NASA/Goddard

Impacting young minds

I've been quiet on the blogging front recently, but I've been pretty busy behind the scenes. This has included engaging in what I see as one of the most important (and fun) parts of my job as a research scientist: outreach.

One of my close friends teaches first grade at Somerset Elementary School in Montgomery County, MD, and she arranged for me to be one of the speakers at their recent Careers Day. I found myself sharing a stage with people from a host of different professions and careers. There was a salad dressing maker, an events organizer, an investment banker, an advisor to President Obama... and me—the planetary geologist.

I was given three 20-minute slots to speak to students who had chosen to hear what I had to say about space. And I was happily surprised that many of these children were eager to ask all kinds of questions. I was even more impressed that some of their more knowledgeable (or geeky) peers were able to step in and proffer answers of their own.

I used my time to show a PowerPoint presentation (full of fun images of space, volcanoes, and such) that I had put together for the occasion, and to let the children have an interactive experience with the MESSENGER postcard mosaic. This 'game' is a great way for kids (and adults) to learn about different features on Mercury and to think about how planetary scientists map the entire surface of another planet.

Fun images depicting aspects of planetary geology.
Credits: Alexander Belousov, Earth Observatory of Singapore, NASA, NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

I also took some rock samples to pass around, including an example of each of the three different types of meteorites: a stony meteorite, an iron meteorite, and a stony-iron meteorite. It is these kinds of rocks that help us understand the interior structure of rocky planets. They come from proto-planets or asteroids that were at some point blasted apart. Before their violent demise, however, these bodies experienced similar evolutionary processes to the planets of our solar system that we know and love. Stony meteorites (in this case represented by an ordinary chondrite) are the equivalent of the exterior crusts of planets.

An ordinary chondrite (about 7 cm across) that was found in Romania. Ordinary chondrites are the most common type of meteorite found on Earth. Credit: ASU/CMS

Iron meteorites—consisting almost entirely of iron and nickel—represent the dense cores of planets, and the stony-irons (or pallasites) come from the boundary between the rocky outer layers of a planetary body and the metal-rich core, known as the core-mantle boundary.

Example of a pallasite (Springwater). These beautiful meteorites contain orange grains of the mineral olivine within a matrix of shiny iron-nickel. Credit: KD Meteorites

The iron meteorite that I had available was a one of a group of samples known as Canyon Diablo. These are the small pieces that remain after their much larger (about 50 m in diameter) parent chunk of space debris smashed into Earth about 50,000 years ago and created the Barringer Meteorite (aka Meteor) crater in Arizona (click here for a 3D-flyover of the crater). This well-preserved impact crater is just over 1 km in diameter and continues to be a site of scientific investigations.

A single piece (a few centimeters across) of the remaining Canyon Diablo meteorite.
Credit: Meteorites Australia

Back in the 1950s isotopic analyses on samples of this meteorite group were used to refine the estimate of Earth's age. Radiometric dating has revealed that many different solar system materials have concordant ages, which we use to provide Earth's age. The estimate given by Claire Paterson in 1956 (4.55 ± 0.07 billion years), based on the Canyon Diablo meteorite is very close to the current estimate of 4.54 ± 0.05 billion years. I propose, therefore, that we send one of these iron meteorite pieces forth for our imaginary alien planetary geologists to discover. Afterall, what piece of information about our home planet and our home solar system is more fundamental than its age?

I'm not sure society has the need for all of the 50+ children I met at Somerset to one day become planetary geologists. But I do hope that at least a handful of them will translate their wonder and joy for things space-related to future careers in a science-focused field. I'm proud to play a very small role in shaping the next generation of civil engineers, meteorologists, and brain surgeons of this world.

A thank-you note from one satisfied customer.