Glen Van Brummelen is Shortlisted for 2013 BSHM Nuemann Book Prize

Glen Van Brummelen - Heavenly Mathematics: The Forgotten Art of Spherical Trigonometry
Shortlisted for the 2013 BSHM Neumann Book Prize, British Society for the History of Mathematics

The British Society for the History of Mathematics (BSHM) has announced the winner of the 2013 Neumann Prize. This prize, named after Oxford mathematician and past BSHM President Dr. Peter Neumann, OBE, is awarded every two years for the best mathematics book containing historical material and aimed at a non-specialist readership.

To read more about the BSHM and this award, click here.

Heavenly MathematicsSpherical trigonometry was at the heart of astronomy and ocean-going navigation for two millennia. The discipline was a mainstay of mathematics education for centuries, and it was a standard subject in high schools until the 1950s. Today, however, it is rarely taught. Heavenly Mathematics traces the rich history of this forgotten art, revealing how the cultures of classical Greece, medieval Islam, and the modern West used spherical trigonometry to chart the heavens and the Earth. Glen Van Brummelen explores this exquisite branch of mathematics and its role in ancient astronomy, geography, and cartography; Islamic religious rituals; celestial navigation; polyhedra; stereographic projection; and more. He conveys the sheer beauty of spherical trigonometry, providing readers with a new appreciation for its elegant proofs and often surprising conclusions.

Heavenly Mathematics is illustrated throughout with stunning historical images and informative drawings and diagrams that have been used to teach the subject in the past. This unique compendium also features easy-to-use appendixes as well as exercises at the end of each chapter that originally appeared in textbooks from the eighteenth to the early twentieth centuries.

Glen Van Brummelen is coordinator of mathematics and the physical sciences at Quest University Canada and president of the Canadian Society for History and Philosophy of Mathematics. His books include The Mathematics of the Heavens and the Earth: The Early History of Trigonometry (Princeton) and Mathematics and the Historian’s Craft.

Dreams of Other Worlds

In the sprint to identify planets beyond our Solar System, scientists scan the skies for habitable worlds similar to Earth with the goal of finding life beyond ours.  With each new confirmation of smaller and more Earth-sized planets, and a possible 400 billion exoplanets in the Milky Way alone, the odds are high that habitable worlds abound. Several of the missions discussed in Dreams of Other Worlds by Chris Impey and Holly Henry have been instrumental in this research, including the beloved Hubble Space Telescope.

Impey_Dreams_F13The book details the methods scientists use to detecting extrasolar planets, the wild variety of planets found so far, and the teams and researchers making the discoveries, including Planethunters.org, the online survey of Kepler data that citizen scientists are currently scouring for evidence of these worlds. The chapter on the Viking mission comments on how, in searching for life on Mars, James Lovelock and Lynn Margulis determined that volatile gases such as oxygen or ozone are replenished by living organisms in Earth’s biosphere and will be important biomarkers of life on exoplanets.  The chapter on the Spitzer mission details the ways complex organisms on Earth developed eyes designed to best use the light of our own star, the Sun, as well as how life forms elsewhere might be adjusted to existence on a planet orbiting a red dwarf star, the most common star type in the Milky Way. While the Hipparcos mission inadvertently identified exoplanets orbiting other stars, its successor mission, Gaia, is poised to detect thousands more.

Beyond artist depictions of exoplanets in orbit of distant stars, the book considers the artwork of Chesley Bonestell whose imaginative paintings of planetary landscapes inspired his and future generations to consider the variable landscapes within our Solar System and beyond.  And, of course, the gold-plated phonograph records attached to the ongoing Voyager spacecraft were intended for civilizations potentially inhabiting an exoplanet in our galactic neighborhood.

The book’s conclusion looks to the upcoming James Webb Space Telescope that will turn its infrared seeking lenses to the search of far-flung worlds.  What we find, the authors remind us, is bound to completely rewrite our understanding of life and where it can exist, as well as our place in the unimaginably vast universe that surrounds us.

 

Read a sample chapter from Dreams of Other Worlds: http://press.princeton.edu/chapters/i10067.pdf

Saturday Night Live is lost in space

 

All evidence to the contrary (ahem, Gravity and just about every other space movie out there), most space missions are now unmanned, but someone does still have to answer the call whether it’s from a stranded George Clooney or a damaged rover. Read Dreams of Other Worlds by Chris Impey and Holly Henry to get a better sense of how NASA and others are expanding the way we understand the universe and our role in it via unmanned space explorations like Cassini, WMAP, and Voyager.

 

 

“Dreams of Other Worlds”: WMAP #WSW2013

Houston, we have lift off!

All week long for World Space Week, we have been posting exclusive excerpts from Chris Impey and Holly Henry’s new book, Dreams of Other Worlds: The Amazing Story of Unmanned Space Exploration. Each day has included an excerpt from a different chapter(s) about a different unmanned spacecraft, along with a picture of the craft that doubles as an iPhone background!

Today is the last official day of World Space Week, so we’ll be finishing it out with an excerpt from Chapter 12, which talks about the curvature of space and how WMAP has helped us to interpret it.

We hope we took one small step for blogging about space, and one giant leap into a space adventure!

WMAPWMAP has not only put us “in tune” with the cosmos; it has refined and sharpened our view of the extraordinary event that created all matter and energy 13.8 billion years ago.
WMAP has taken quantities that were poorly known or only hinted at and turned them into well-measured cosmological parameters. The temperature is measured to a precision of a thousandth of a degree. Since space can be curved according to general relativity, the universe can act as a gigantic lens. To do this vast optics experiment we look at the microwaves that have been traveling across space for billions of years. The fundamental harmonic of the microwave radiation sets the size of the “spot.” Radiation from that typical spot size travels through space and the angular size can be magnified or de-magnified depending on whether space has positive or negative curvature, which is like the universe acting as either a convex or a concave lens. WMAP has shown that the spot size doesn’t change so the universe is behaving like a smooth sheet of glass. The inference is that space is not curved; the universe is flat to a precision of 1 percent. This is just as expected from inflation.

Think you know all about these missions? Take our quiz and find out!
Proud of your score? Tweet it! #WSW2013

World Space Week Round-Up #WSW2013

All this week for World Space Week, we’ve been posting excerpts from Chris Impey and Holly Henry’s new book, Dreams of Other Worlds: The Amazing Story of Unmanned Space Exploration, and while that’s an amazing book, we decided that in order to give World Space Week all of the cosmic attention it deserves, we would put together an interstellar round-up to fire up your engines and blast you to infinity… and beyond!

Beyond UFOs
Beyond UFOs: The Search for Extraterrestrial Life and Its Astonishing Implications for Our Future

By: Jeffrey Bennett

This book describes the startling discoveries being made in the very real science of astrobiology, an intriguing new field that blends astronomy, biology, and geology to explore the possibility of life on other planets. This book goes beyond UFOs to discuss some of the tantalizing questions astrobiologists grapple with every day: What is life and how does it begin? What makes a planet or moon habitable? Is there life on Mars or elsewhere in the solar system? How can life be recognized on distant worlds? Is it likely to be microbial, more biologically complex–or even intelligent? What would such a discovery mean for life here on Earth?

Titan Unveiled
Titan Unveiled: Saturn’s Mysterious Moon Explored

By: Ralph Lorenz and Jacqueline Mitton

In the early 1980s, when the two Voyager spacecraft skimmed past Titan, Saturn’s largest moon, they transmitted back enticing images of a mysterious world concealed in a seemingly impenetrable orange haze. Titan Unveiled is one of the first general interest books to reveal the startling new discoveries that have been made since the arrival of the Cassini-Huygens mission to Saturn and Titan.

From Dust To Life
From Dust to Life: The Origin and Evolution of Our Solar System

By: John Chambers & Jacqueline Mitton

The birth and evolution of our solar system is a tantalizing mystery that may one day provide answers to the question of human origins. This book tells the remarkable story of how the celestial objects that make up the solar system arose from common beginnings billions of years ago, and how scientists and philosophers have sought to unravel this mystery down through the centuries, piecing together the clues that enabled them to deduce the solar system’s layout, its age, and the most likely way it formed.

Fly Me to the Moon
Fly Me to the Moon: An Insider’s Guide to the New Science of Space Travel

By: Edward Belbruno
With a foreword by Neil deGrasse Tyson

Belbruno devised one of the most exciting concepts now being used in space flight, that of swinging through the cosmos on the subtle fluctuations of the planets’ gravitational pulls. His idea was met with skepticism until 1991, when he used it to get a stray Japanese satellite back on course to the Moon. The successful rescue represented the first application of chaos to space travel and ushered in an emerging new field. Part memoir, part scientific adventure story, Fly Me to the Moon gives a gripping insider’s account of that mission and of Belbruno’s personal struggles with the science establishment.

The Milky Way
The Milky Way: An Insider’s Guide

By: William H. Waller

This book offers an intimate guide to the Milky Way, taking readers on a grand tour of our home Galaxy’s structure, genesis, and evolution, based on the latest astronomical findings. In engaging language, it tells how the Milky Way congealed from blobs of gas and dark matter into a spinning starry abode brimming with diverse planetary systems–some of which may be hosting myriad life forms and perhaps even other technologically communicative species. It vividly describes the Milky Way as it appears in the night sky, acquainting readers with its key components and telling the history of our changing galactic perceptions.

Universe
The Universe in a Mirror: The Saga of the Hubble Space Telescope and the Visionaries Who Built It

By: Robert Zimmerman
With a new afterword by the author

The Hubble Space Telescope has produced the most stunning images of the cosmos humanity has ever seen. It has transformed our understanding of the universe around us, revealing new information about its age and evolution, the life cycle of stars, and the very existence of black holes, among other startling discoveries. But it took an amazing amount of work and perseverance to get the first space telescope up and running. The Universe in a Mirror tells the story of this telescope and the visionaries responsible for its extraordinary accomplishments.

Think you know all about missions in space? Take our quiz and find out!
Proud of your score? Tweet it! #WSW2013

“Dreams of Other Worlds”: Chandra and HST #WSW2013

Houston, we have lift off!

All week long for World Space Week, we will be posting exclusive excerpts from Chris Impey and Holly Henry’s new book, Dreams of Other Worlds: The Amazing Story of Unmanned Space Exploration. Each day will include an excerpt from a different chapter(s) about a different unmanned spacecraft, along with a picture of the craft that doubles as an iPhone background!

Today we have two excerpts. The first is from Chapter 10, and it describes some of the leaps and bounds we have been able to make in black hole exploration thanks to Chandra. The second excerpt is from Chapter 11, which talks about what is probably the most famous spacecraft, the Hubble Space Telescope.

Tomorrow will bring another chapter and another adventure, so stay tuned!

chandra99-13Chandra has the sensitivity to detect stellar black holes hundreds of light-years away. Only about twenty binary systems have well-enough measured masses to be sure the dark companion is a black hole, but X-ray observations can be used to identify black holes with fairly high reliability. The examples studied with X-ray telescopes are the brightest representatives of a population of about 100 million black holes in the Milky Way.
X-ray observations have also pushed the limit of our understanding of black holes. In 2007, a research team used Chandra to discover a black hole in M33, a nearby spiral galaxy. The black hole was sixteen times the mass of the Sun, making it the most massive stellar black hole known.32 Moreover, it was in a binary orbit with a huge star seventy times the Sun’s mass. The formation mechanism of the black hole that placed it in such a tight embrace with its companion is unknown. This is the first black hole in a binary system that shows eclipses, which provides unusually accurate measurements of mass and other properties. The massive companion will also die as a black hole, so future astronomers will be able to gaze on a binary black hole where energy is lost as gravitational radiation and the two black holes dance a death spiral as they coalesce into a single beast.
hubble89-13Above all scientific projects, the Hubble Space Telescope encapsulates and recapitulates the human yearning to explore distant worlds, and understand our origins and place in the universe. Its light grasp is 10 billion times better than Galileo’s best spyglass, and many innovations were needed for it to be realized: complex yet reliable instruments, the ability for astronauts to service the telescope, and the infrastructure to support the projects of thousands of scientists from around the world. The facility and its supporters experienced failure and heartache as well as eventual success and vindication.
Hubble’s legacy has touched every area of astronomy, from the Solar System to the most distant galaxies. In the public eye, it’s so well known that many people think it’s the only world-class astronomy facility. In fact, it operates in a highly competitive landscape with other space facilities and much larger telescopes on the ground. Although it doesn’t own any field of astronomy, it has made major contributions to all of them. It has contributed to Solar System astronomy and the characterization of exoplanets, it has viewed star birth and death in unprecedented detail, it has paid homage to its namesake with spectacular images of galaxies near and far, and it has cemented important quantities in cosmology, including the size, age, and expansion rate of the universe.

Think you know all about these missions? Take our quiz and find out!
Proud of your score? Tweet it! #WSW2013

“Dreams of Other Worlds”: Hipparcos and Spitzer #WSW2013

Houston, we have lift off!

All week long for World Space Week, we will be posting exclusive excerpts from Chris Impey and Holly Henry’s new book, Dreams of Other Worlds: The Amazing Story of Unmanned Space Exploration. Each day will include an excerpt from a different chapter(s) about a different unmanned spacecraft, along with a picture of the craft that doubles as an iPhone background!

Today we have two excerpts. The first is from Chapter 8, which talks about the first star charts, which were created by the Greek astronomer, Hipparchus (for whom the Hipparcos was named). The second excerpt is from Chapter 9, explaining some of the adversities Spitzer had to face before it was able to go into space.

Tomorrow will bring another chapter and another adventure, so stay tuned!

HipparcosFor thousands of years, all we’ve known of Hipparchus’s star guide were descriptions by Ptolemy. But astronomer Bradley Schaefer asserts that, indeed, the Farnese Atlas, a statue of the Greek figure Atlas kneeling while holding on his shoulders a globe of constellations, represents the stars and constellations known to the ancient Greeks. He contends that the statue “is the oldest surviving depiction of the set of the original Western constellations, and as such can be a valuable resource for studying their early development.”18 Schaefer realized after a detailed study of the globe that the constellations depicted match the night sky in the era and from the location where Hipparchus lived in 129 BC. As evidence in favor of this possibility, Schaefer writes: “First, the constellation symbols and relations are identical with those of Hipparchus and are greatly different from all other known ancient sources. Second, the date of the original observations is 125 ± 55 BC, a range that includes the date of Hipparchus’s star catalogue (c. 129 BC) but excludes the dates of other known plausible sources.” Schaefer concludes that “the ultimate source of the position information [of the constellations on the globe] used by the original Greek sculptor was Hipparchus’s data.”

SpitzerSpitzer, from its earliest inception, was especially designed for infrared astronomy and is sensitive enough to detect infrared signatures of stars and galaxies billions of light-years away. The space telescope has been instrumental in unveiling small, dim objects like dwarf stars and exoplanets and can even determine the temperature of their slender atmospheres. Originally proposed in the late 1970s as NASA’s Space Infrared Telescope Facility, the Spitzer Space Telescope suffered from uncertainty, a delay after the loss of the space shuttle Challenger, near-cancellation, congressional limbo, budget cuts, and “descoping.” Nevertheless, in 2003 the telescope was finally launched, after being renamed subsequent to a public opinion poll conducted by NASA. The last of NASA’s four Great Observatories, the $800 million telescope was named after Lyman Spitzer, an early advocate of the importance of orbital telescopes.13 After launch, the spacecraft took about 40 days to cool to its operating temperature of 5 Kelvin. Once cooled, it took just an ounce of liquid helium per day to maintain its detectors at their operating temperature. A solar panel facing the Sun serves to gather power and protect the telescope from radiation.

Think you know all about these missions? Take our quiz and find out!
Proud of your score? Tweet it! #WSW2013

“From the edge of the Solar System” exclusive article by Holly Henry (#WSW2013)

NASA recently reported that Voyager 1 has now streaked beyond the influence of our Sun’s magnetic field.  The twin Voyager spacecraft, launched in 1977, captured with unprecedented clarity the wild and unexpected planetary geographies within our own Solar System, revealing the moons of Jupiter and Saturn as worlds in their own right, replete with mountains, lakes, riverbeds, volcanoes, geysers, as well as storms and weather—even if the rain on Titan is in the form of liquid methane, and the briny geysers of Enceladus rocket thousands of miles above its surface

Cassini Imaging Team, SSI, JPL, ESA, NASA This photo of water geysers spouting from Saturn's moon Enceladus was taken by NASA's Cassini orbiter in October 2007.

Cassini Imaging Team, SSI, JPL, ESA, NASA
This photo of water geysers spouting from Saturn’s moon Enceladus was taken by NASA’s Cassini orbiter in October 2007.

Cultural geographer Denis Cosgrove observed that the terrain of Mars and the moons of the outer planets “are increasingly present” to us.   As their landscapes settle into the imagination, these planetary bodies have emerged as recognizable, remembered, and even cherished terrain—places, Cosgrove noted, of “detailed human understanding and care.” Asked to name a landmark on the Moon, most people would probably answer the Sea of Tranquility, the landing site of Apollo 11. A few might mention the lunar Apennines, landing site of Apollo 15.  But ask most fifth graders about Olympus Mons, Tharsis Bulge, or Valles Marineris and they not only readily reply, but immediately envision these remarkable topographic features.  Mars has become a place we know, remember, and dream of exploring, someday with boots on the ground.

It was the Viking orbiters that brought back the first stunning images of the geography of Mars. By the late 20th century, Mars in particular emerged as the familiar landscape we recognize and know.  It is as if a Mercator’s projection of Mars lifted from its paper and rounded into a globe with tangible polar ice caps, soaring volcanoes, immense rift valleys, and plains of crescent, barchan dunes.  Today these iconic features of Martian terrain preoccupy, and persist in, the human imagination.  Images from Viking and later missions allow us to turn the globe of Mars in our mind and trace with our fingers the planet’s volcanoes, its broken and unzipped canyons, its ancient and desiccated riverbeds. With Spirit and Opportunity, and now Curiosity, we’ve explored in fine detail Martian geology and have discovered that ancient Mars harbored surface water that could have sustained life. While the image of the whole Earth, taken by the crew of Apollo 17, is estimated to be the most reproduced image in photographic history, as a result of Voyager, Viking, Cassini and other NASA missions, by the late twentieth century the planetary real estate of our Solar System emerged as equally tangible and indelibly ingrained in the human imagination. The geographies of Jupiter’s moon Europa and Saturn’s moon Titan are reconfiguring our sense of place, this time in relation to the Solar System itself.

Even now, Voyager 1, at roughly 11.7 billion miles from Earth, and Voyager 2 at 9.5 billion miles away are plunging into the interstellar void.   Their feeble radio signals take about a day to reach Earth as the Voyager 1 silently streaks through space at approximately 38,000 miles per hour. By modern standards, the Voyager spacecraft are obsolete.  They communicate at 160 bits per second, which is 25,000 times slower than basic broadband internet services, and function on less than three light bulbs’ worth of power.  On Earth, 8-track tape decks and LP records have been relegated to yard sales; at the edge of the Solar System, the Voyagers’ technology is still cutting edge.  As they continue to report on what Stephen Pyne calls the soft geography at the edge of the heliopause, the Voyagers represent a vast architecture that has powerfully shaped the human imagination in the 20th and 21st century.

Literary and cultural critic Walter Benjamin claimed that architecture inevitably reflects the mythos of its people.  As David Spurr explains, Benjamin argued that architecture often translates the deep, unstated narratives of a culture into brick or stone. The same might be argued of the far flung Voyagers, whose mission is only possible via an architecture that spans great gulfs of space, extending from Voyager 1 at the edge of the Solar System, to the Goldstone Deep Space Network in the Mojave desert, and its radio dish networks in Madrid or Canberra, to Caltech in Pasadena, and NASA’s Jet Propulsion Laboratory.  Written into the architecture of these spacecraft, that carry with them a phonograph record of photos and recorded greetings from Earth, is a primal human attribute: that we stand amazed at life’s possibility, even in the tiny packet of an ant, or a sphere of microscopic phytoplankton.  Voyager not only opened a window to the many worlds within our Solar System, but the mission equally embodies our cultural dream of finding life elsewhere in the vast abysses of space.

 


Holly Henry is Professor of English at California State University, San Bernardino, whose research focus is the cultural studies of science. She is co-author with astronomer Chris Impey of Dreams of Other Worlds, an analysis of 11 iconic NASA astronomy and planetary science missions.

World Space Week Quiz Answers! #WSW2013

Dreams of Other WorldsIn case you’ve been sitting on the edge of your seat since you took our World Space Week Quiz, dying to know why you got a 91% instead of 100%, anticipate no longer! Check out the answers below and be sure to also pick up a copy of Chris Impey and Holly Henry’s brand new book, titled Dreams of Other Worlds: The Amazing Story of Unmanned Space Exploration.


1) Which unmanned spacecraft landed on Mars for the first time in US history in 1976?

Viking! The Viking probes were the first to orbit and touch down on Mars, taking high-res photos and exploring for any potential signs of life. (no signs of any Martian activity yet…)

2) Which space probe collected cosmic dust from the comet Wild 2 in 1999?

Stardust! The Stardust followed Wild 2 (a comet approximately 5 kilometers in diameter) to follow samples and take photos of its surface.

3) Which satellite was the first to map the stars and was named after a Greek astronomer?

Hipparcos! Named in reference to the Greek astronomer, Hipparchus, the Hipparcos contains various datasets for known stars, allowing us to catalog their position and distance.

4) Which two spacecrafts were known as the “Tireless Twins” for their long-distance exploration of other planet’s systems?

The Voyagers! This gruesome twosome was originally supposed to just explore Jupiter and Saturn, bu they ended up going all of the way out to Uranus and Neptune as well.

5) Which space telescope launched in 1999 allowed NASA to observe X-rays outside of Earth’s atmosphere?

Chandra! Known as one of the four “Great Observatories”, Chandra is still observing X-rays from space today.

6) Which spacecraft launched in 1995 monitors the “humming” of the Sun’s sound waves?

SOHO! The Solar and Heliospheric Observatory (or SOHO) both explores the outer layers of the Sun and gets readings of radiant energy (in the form of sound waves) to learn about its interior structure.

7) What two spacecrafts were the first of the Mars Exploration Rover (MER) Missions to explore the surface and geology of Mars?

Spirit and Opportunity! This dynamic duo has been exploring the surface of Mars for quite some time, taking samples that help determine whether or not there was ever water on Mars, the general geology of the planet, and whether or not life could potentially be supported there.

8) Along with COBE, which spacecraft helps to map the radiant energy let off by the Big Bang?

WMAP! The WMAP measures differences in the temperature of the Big Bang’s remnant radiant heat in the sky to help us better understand the Big Bang as a model.

9) Which space telescope, launched in 2003, has the ability to see through interstellar dust to observe the distant formation of stars?

Spitzer! The Spitzer Space Telescope was the first infrared telescope of its time, allowing it to take photographs in space that were far better than any we had seen up until that point.

10) Which space telescope observes Earth atmosphere and has been in operation for over three decades?

Hubble! Probably the most famous of all the spacecrafts in this quiz, the Hubble Space Telescope is the only telescope designed to be serviced by astronauts in space.

11) Which spacecraft launched in 1997 orbits Saturn, exploring both the planet and its rings?

Cassini! After launching in 1997, it took Cassini seven years to reach Saturn’s orbit.


Proud of your score? Tweet it! #WSW2013


Want to see what these sorts of spacecrafts look like? Check out the infographic below!
00_impey_timeline

“Dreams of Other Worlds”: Stardust and SOHO #WSW2013

Houston, we have lift off!

All week long for World Space Week, we will be posting exclusive excerpts from Chris Impey and Holly Henry’s new book, Dreams of Other Worlds: The Amazing Story of Unmanned Space Exploration. Each day will include an excerpt from a different chapter(s) about a different unmanned spacecraft, along with a picture of the craft that doubles as an iPhone background!

Today we have two excerpts. The first is from Chapter 6, and our excerpt talks about how Stardust was able to keep up with the intense speed of the Wild 2 comet to photograph it. The second excerpt is from Chapter 7, which describes “space weather”, which SOHO is able to track to warn us of any changes in our solar system.

Tomorrow will bring another chapter and another adventure, so stay tuned!

StardustMission controllers tried to sneak up behind Wild 2 to minimize the relative speed of the two objects. Even so Stardust was moving 13,000 mph, or five times the speed of a rifle bullet, as it flew through the glowing coma of the comet. It took seventy-two close-up photographs. That may not seem like many, but keeping the relatively small comet in the camera field of view during such a fleeting and high-speed encounter was a major feat.10 The images showed a surface riddled with depressions with flat bottoms and sheer walls, ranging in size from dozens of meters to several kilometers. The comet itself is irregular in shape and five kilometers in diameter. The features are impact craters and gas vents; ten vents were active when Stardust flew by.
The neatest trick Stardust had up its sleeve was gathering material from the comet tail. [...] All of the solid objects in the universe were built from microscopic dust particles—stardust. The probe was designed to capture material too small to see in its eight-minute ride through the comet’s tail and then its long ride home.
SOHOData from SOHO, and increasing concern over the impact of space weather, caused NASA to commission a new study in 2009. The resulting report provides clear economic data to quantify the risk to the near-Earth environment from episodes of intense solar activity. Extreme space weather is in a category with other natural hazards that are rare but have far-reaching consequences, like major earthquakes and tsunamis.34 It’s likely that more than once in the next twenty years there will be an “electro-jet disturbance” that disrupts the national power grid. In the 1989 event, the loss of some portions of the grid put stress on others and led to a cascade affect. The end result was power outages affecting more than 130 million people and covering half the country.
SOHO cannot prevent these natural disasters, but it can give two or three days’ notice of Earth-directed disturbances. And as we become more accurate in anticipating space storms, operators can place satellites in protective modes, shut down or limit power grids, redirect commercial flights, warn oceanic cruise and cargo ships, and place astronauts working on the International Space Station in the safest possible location on the station. Such steps will not only save lives but also protect the information systems that sustain our electronically fragile and networked global community.

Think you know all about these missions? Take our quiz and find out!
Proud of your score? Tweet it! #WSW2013

“Dreams of Other Worlds”: Voyager and Cassini #WSW2013

Houston, we have lift off!

All week long for World Space Week, we will be posting exclusive excerpts from Chris Impey and Holly Henry’s new book, Dreams of Other Worlds: The Amazing Story of Unmanned Space Exploration. Each day will include an excerpt from a different chapter(s) about a different unmanned spacecraft, along with a picture of the craft that doubles as an iPhone background!

Today we have two excerpts. The first is from Chapter 4, and our excerpt does its best to describe exactly how far away the Voyager spacecrafts are, and how completely wild that is. The second excerpt is from Chapter 5, which describes the way in which Cassini travels around Saturn without getting sucked into its gravitational pull.

Tomorrow will bring another chapter and another adventure, so stay tuned!

voyager77-13To see why these spacecraft represented such a leap in our voyaging through space, consider a scale model of the Solar System where the Earth is the size of a golf ball. On this scale, the Moon is a grape where the two objects are held apart with outstretched arms. That gap is the farthest humans have ever traveled, and it took $150 billion at 2011 prices to get two dozen men there. Mars on this scale is the size of a large marble at the distance of
1,100 feet at its closest approach. As we’ve seen, it took an arduous effort spanning more than a decade before NASA successfully landed a probe on our nearest neighbor. A very deep breath is needed to explore the outer Solar System. In our scale model, Jupiter and Saturn are large beach balls 1.5 and 3.5 miles away from Earth, respectively, and Uranus and Neptune are soccer balls 7 and 12 miles from the Earth. This large step up in distance was a great challenge for spacecraft designers and engineers. On this scale, the Voyager 1 and 2 spacecraft are metallic “motes of dust” 48 and 37 miles from home, respectively.
cassini97-13Over its core mission, Cassini orbited Saturn 140 times. To see Saturn, its rings, its largest moons, and its magnetosphere from all conceivable angles, Cassini is using its rockets and seventy gravity-assist flybys of Titan to tweak its orbit size, period, velocity, and inclination from Saturn. As the largest moon, Titan isthe most useful in “steering” Cassini around the Saturnian system. Each Titan flyby is engineered to return Cassini into the proper trajectory for its next Titan flyby. Encounters with other moons are performed opportunistically with what’s called a targeted flyby. About fifteen are planned by the end of the mission, half to the intriguing small moon Enceladus. From 2004 through 2011, Cassini did a dizzying hundred flybys, with another dozen completed in 2012. NASA hosts a clock counting down the time until the next swooping visit to a moon and coyly calls these “Tour Dates” to appeal to a younger generation.26 By clever planning, NASA engineers have doubled the length of the mission even though just a quarter tank of fuel remains.

Think you know all about these missions? Take our quiz and find out!
Proud of your score? Tweet it! #WSW2013

“Dreams of Other Worlds”: The Mars Rovers #WSW2013

MERHouston, we have lift off!

All week long for World Space Week, we will be posting exclusive excerpts from Chris Impey and Holly Henry’s new book, Dreams of Other Worlds: The Amazing Story of Unmanned Space Exploration. Each day will include an excerpt from a different chapter about a different unmanned spacecraft, along with a picture of the craft that doubles as an iPhone background!

Today’s excerpt is from Chapter 3, and it talks about our strategy for learning more about Mars, and what the Mars Rovers, Spirit and Opportunity, are doing to help us with that.

Tomorrow will bring another chapter and another adventure, so stay tuned!

Decoding the Red Planet

As we saw in the last chapter, Mars seems dead to the orbiters that daily send back images of the surface. The atmosphere is tenuous, ultraviolet radiation and cosmic rays scorch the soil, and it rarely gets above freezing even on the balmiest summer day.15 It’s unlikely any form of life could exist on the surface now, but Mars has not always been so inhospitable. NASA’s strategy in searching for life in the Solar System is to “follow the water,” and even if there’s no surface water now, there was in the past. Each of the Mars Exploration Rovers, Spirit and Opportunity, was designed for just a ninety-day mission. In the end, they have vastly exceeded expectations with their indomitable traverses of the forbidding Martian terrain. Think of them as twin robotic field geologists whose primary goal is to search for the signposts of water.16 The record of past water can be found in the rocks, minerals, and landforms on Mars, particularly those that could only have formed in the presence
of water.

Think you know all about these missions? Take our quiz and find out!
Proud of your score? Tweet it! #WSW2013