Jonathan McDowell has X-ray vision. That is, he has the eyesight, foresight and insight to see deep into outer space—and back in time—through X-ray radiation detected by Chandra, the coolest flying observatory this side of the Hubble telescope.
Or rather, THAT side of the Hubble telescope. Hubble circles a mere 354 miles above the Earth. Chandra orbits our planet at an altitude ranging from about 10,000 miles to 82,000 miles. On the outer edge of its elliptical orbit, it is one-third as far away as the Moon.
Jonathan pulls out a red marker pen and starts drawing concentric circles and ovals on a notebook sheet to illustrate the relative orbits of various satellites and observatories. Pamelia and I are rapt. We are sitting across from him at his office in the Harvard-Smithsonian Center For Astronomy (casually known as the CfA) in Cambridge, Mass. Jonathan is one of the world's leading astrophysicists. (He even has an asteroid named after him.) He works with Chandra and collaborates with similarly brilliant MIT astrophysicists at the Smithsonian Astrophysical Observatory at the CfA. He's friendly and witty and creative. In a deft blend of science and art, he helped curate The Evolving Universe, a show of cosmic images currently on display at the Smithsonian's National Museum of Natural History in Washington, D.C.
Jonathan is helping Pamelia and me continue what we are calling our 13.7-billion-year expedition to the frontier of knowledge (which we hope won't take quite that long). We are traveling to places near and far to collect expert voices and insights for The Naturalist's Notebook's 2013 (and beyond) installations and the many components of The 13.7-Billion-Year Hue-Story Of Our Life initiative, which is our 24-spectral-color-coded timeline and global science+arts+education project.
That quest brought us to Cambridge, and on this day (after giving us a quick look at Harvard's Great Refractor telescope, built in 1847), Jonathan was enriching our knowledge of everything from the size of the black hole at the center of the Milky Way galaxy to the importance to astronomers of studying clues offered by Pamelia's favorite natural phenomenon, the electromagnetic spectrum. "That is what unlocked the universe for us," he said.
Jonathan's red-pen sketch of orbits helped us draw a mental picture of what's flying around above us. Imagine yourself looking up at the sky. You might catch a glimpse at dusk or dawn of the Sun glinting off the International Space Station, which circles about 200 to 250 miles up (and zips around the globe once every 91 minutes), but with the naked eye you won't see Hubble, another 100 or so miles up, and you definitely won't see Chandra or even the satellites that serve up your DirecTV or SiriusXM radio. That latter group is in "geo-stationary" orbit, meaning the satellites remain over the same spot on Earth at all times. To do that, they have to orbit at a height of nearly 23,000 miles, enabling them to circle the planet once every 24 hours. Said Jonathan, who has a gift for describing science in understandable terms and fun metaphors, "What they've done is build a [TV] tower 23,000 miles high and take the scaffolding away."
He explained the differences between X-ray telescopes, such as Chandra, visible-light telescopes, such as Hubble, and infrared telescopes, such as Spitzer, the third of NASA's so-called Great Observatories and the only one that does not orbit the Earth at all (it instead orbits the Sun, following the same path as the Earth). In simple terms, X-ray observatories see very hot objects (X-rays are high-energy waves), visible-light telescopes see medium-temperature objects and infrared observatories see cooler objects. That often means that Spitzer sees stars being born, Hubble sees stars in mid-life and Chandra sees stars that are dying in huge, super-hot explosions. Seeing only the visible spectrum—which is but a teeny, tiny band of the full spectrum—would leave astronomers largely in the dark. "Imagine if you were walking around the world and you could only see things that were green," said Jonathan. "Everything else would be invisible."
You probably already know that the Hubble telescope is named for American astronomer Edwin Hubble, who used the electromagnetic spectrum in the 1920s to make the then-startling discovery that the universe is expanding. The Spitzer observatory is named for theoretical physicist Lyman Spitzer, who in 1946 came up with the very idea of putting telescopes in space. Spitzer was influenced in his career by Chandra's brilliant namesake, the late Indian-American Nobel Prize winner Subrahmanyan Chandrasekhar. He was more commonly known as Chandra, a Sanskrit word meaning, aptly enough, moon or luminous.
Our luminous meeting with Jonathan ended with his saying, "It's a privilege just to be a part of this," and we could fully understand. Perhaps you'd like to hear Jonathan for yourself? Click on the link below for Mary Kuechenmeister's excellent, brand-new interview with him for the Story Preservation Initiative:
Now Back to Those Rhinos... I wasn't familiar with Katharine Lane Weems (1899-1989), but she was one of America's first acclaimed female sculptors and one of the world's most respected animal sculptors. She lived in Boston, and many of her public pieces are at Harvard and the Boston Museum of Science. Here's a closer look at her work outside Harvard's Biological Laboratories building.
A World of Glass
Answer to the Last Puzzler House finches are an introduced species and were brought to New York City from England in the early 1850s.
Today's Puzzlers 1) While on our visit to Harvard's Museum of Comparative Zoology, we passed the door shown in the photo below. What field of study is malacology?
a) the study of disease-carrying insects b) the study of mollusks (such as snails, clams and squid) c) the study of animal brains
2) We also saw the plaque below. It honors a president of Harvard who, pursuing his late son's dream, first proposed that land be set aside on Mount Desert Island for what would eventually become Acadia National Park. Who was he?
a) Charles Eliot b) Theodore Roosevelt c) John D. Rockefeller