view of cassini spacecraft near Saturn's rings


The Cassini spacecraft, after 13 years exploring Saturn and its moons, broke apart yesterday during entry into the planet’s atmosphere. There’s pretty much nothing not interesting about this mission: the Huygens probe parachuting onto Titan, the discoveries that answered questions or sparked new ones about Saturn and its moons, the risky, cinematic last set of 22 orbits that looped between the planet and its rings:

Even the reason for destroying Cassini is about looking to the future: by using the last bits of fuel to control its path, NASA and the ESA avoid the risk of it crashing onto Titan or Enceladus where it could contaminate environments potentially friendly to life.

A rendering of Cassini on a flyover past the water vapor plumes on Enceladus, which contain organic compounds.”

You can find NASA’s valediction for Cassini here as well as a video summing up the mission.

And below, from a few days ago, one of its last images: the moon Daphnis making ripples in Saturn’s rings.
This image of Saturn's outer A ring features the small moon Daphnis and the waves it raises in the edges of the Keeler Gap. The image was taken by NASA's Cassini spacecraft on Sept. 13, 2017.

chart showing reports of animals sensing earthquakes
animals, science

Nonsystematic and Collected from Many Sources

I love this chart, from a 1981 review paper on whether animals can anticipate earthquakes.

It plots instances of odd behavior, for a multitude of species, based on time before a quake and distance from the epicenter. To me, it’s like a data-based graphic equivalent to herding cats. The caption:

Fig. 1. Distribution of animal behavior incidents according to the distance from the epicenter and the time before the main shock of 36 different earthquakes in Europe, Asia, North America, and South America. Symbols indicate reports on the following animals: catfish, eels, other fish, frogs, snakes, turtles, sea birds, chickens, other birds, dogs, cats, deer, horses, cows, rats, and mice. Data are nonsystematic and collected from many sources. [Kilian, 1964; von Hentig, 1923; Simon, 1975; Lee et al, 1976; Academia Sinica, 1977a, b; Shaw, 1977; Rikitake, 1978a, b; Tributsch, 1978]

A little while back, I wrote about research into whether animals can somehow predict earthquakes. It’s a great subject!

For years people have wrestled with the question of whether a link can be found, whether animals can somehow act as a warning system that will tell us to seek shelter before an earthquake. But one of the challenges, whether in terms of first identifying the behavior or of later monitoring your warning-animal, is consistency and knowing that you’ve made a robust observation. And one phrase in that caption pretty much nails the problem for drawing broader conclusions: “data are nonsystematic and collected from many sources”.

Which leads us to ask, what would be systematic data? Hard to say. As I wrote in that Beast article, most of us can’t sit around staring at Rover, taking careful notes, just in case an earthquake strikes. And yet that might be what it takes. As one researcher wrote more than 30 years ago:

Should we find that our animals indeed do sense impending earthquakes so much the better. If we do not, however, there is danger of extrapolating our results to the statement that no animal anticipates seismic events and that further studies are not warranted. I don’t know how to deal with this paradox except to urge the USGS to lobby for sufficient funds to allow installation of a greater diversity of species in seismically active areas. An important part of the lobby would be a plea for patience and understanding of the gamble and costs incurred as one simply maintains the experiments and waits for an earthquake to happen.

That was written by a UCLA biologist who’d spent a couple years observing pocket mice and kangaroo rats near Palm Springs. The rodents seemed to run on their wheels and dart through passages more often just before earthquakes.

multimedia, science

Night of the Planet Hunter, Youtubed

Last week, someone asked if some of my work from a few years ago could have been published to Youtube. Great question. Way back in 2008/2009, if you were working with an organization that was interested in experimenting outside their traditional media format—say, a magazine publishing an audio slideshow—you’d sometimes find that despite the interest, there was a more fundamental question: what, exactly, to do with the resulting story. There might be technical constraints (which was the case with the story below), or certain editorial imperatives (self-hosted video; wanting people to visit your site as opposed to making something embeddable, etc) would make things complicated.

In the case of this 2008 audio slideshow about searching for exoplanets (the pre-Kepler era), my editor said I might as well publish it to my site since they couldn’t really publish the Flash-based output from Soundslides (speaking of which, ugh, Flash). Since then, some of these things have loosened up—see, for example, the Wired video I pitched in on with an early draft script, that went straight to Youtube. SoundSlides itself developed a convert-to-Youtube-friendly-format option online, which is what I used here.

Anyway, here we finally have an easily embeddable version. And below that, the brief write-up that went with it.

California Goes Planet Hunting

Until 1995, exoplanets—planets orbiting sun-like stars—were more figment than fact, the stuff of sci-fi novels. But in 1995, a Swiss group discovered the first known example, called 51 Pegasi b, and since then, astronomers have documented more than 300 exoplanets. Of those, nearly half have been discovered by the team led by Cal astronomy professor Geoff Marcy, who directs the Center for Integrative Planetary Science.

California recently checked in with Professor Marcy to find out more about his work. The results: an audio slideshow of a night searching for planets with Marcy (above) and a Q & A with Marcy about his work (below), both produced by Timothy Lesle.

California: How do you describe what you do?

Geoff Marcy: I think every young person, at some point, looks up at the night sky and wonders if those “suns” harbor any planets, especially earth-like planets. We wonder, “Is anyone out there?” My research has been to search the nearest 1000 stars for planetary systems, with the hope of finding possible oases for life. My group works day and night using the world’s largest optical telescope, the Keck telescope. NASA and the University of California provide the telescope time. Three NASA space-borne telescopes hold real promise for the future. Kepler will launch in 2009 and is designed to detect Earth-like planets, which have never been found. It will search for stars that dim repeatedly, as a sign that earths are crossing in front of the star, blocking starlight.

How did you get into planet hunting?

When I finished my Ph.D., I didn’t have any good ideas about what to do next. I attempted to continue my research, measuring the magnetic fields on Sun-like stars. But such measurements are very difficult, and I could tell it wasn’t going well. I felt lost and incompetent. Resigned to mediocrity, I decided I should do research that captured my imagination, no matter how unlikely it was to succeed. For the next 10 years my collaborator, Paul Butler, and I tried to discover planets, without success. I was quite distressed the entire time, but didn’t feel that I could quit. When we found our first planets, most people didn’t believe us. A Canadian astronomer and an American astronomer promoted alternative interpretations, saying we were fooling ourselves and tricking others. But we persisted. I was so depressed when people didn’t believe me that I had to get away from astronomy. I took up tennis, playing every day. I still play tennis every day.

If a star looks small, a planet must be impossible to see.

Detecting a planet near a star is like trying to see a speck of dust next to a flashlight, located 1000 miles away. We find planets by using a trick. The stars are yanked by the gravitational pull of the planet. We watch the stars to see if they are moving around in circles or stationary. If they move, we know a planet is there. Massive planets yank more strongly on the star, allowing us to measure the planet’s mass. And the time it takes for the star to move in a circle is the same time it takes the planet to orbit the star. So we learn quantitative information about the planet, even though we don’t see it at all.

My team has discovered extraordinary and bizarre new worlds. Some orbit so close to their star that they are just skimming above the star’s surface, [which is] blow-torching the planet to thousands of degrees. Others travel along stretched-out, elongated orbits, with the star flinging the planet far, only to let it plummet back. The circular orbit of the Earth is a fluke among planets in the universe.

Will we be visiting them one day?

Some day we humans will devise propulsion systems that allow us to send spacecraft to the stars. At first the payloads will be sensitive cameras, sending back detailed pictures of another world, with its oceans, lakes, rivers, and waterfalls. Perhaps we’ll even see the life forms living there. Later, we will travel to the stars ourselves, to visit those worlds and live there, like the pioneers in the Old West. Ultimately, our travels to other worlds will help preserve our species, protecting us against catastrophe on any one planet, including our home Earth.

Tim Lesle also wrote about a serendipitous supernova study in the November/December 2008 issue of California.


Wow! (Or, as the driver initially says, according to a translation in the New Yorker, “What the fuck is that?”)

Surely one of the most interesting things to be seen on the planet these last twenty-four hours is this meteor streaking across the Russian sky, brightening up the Chelyabinsk dawn.

But not everyone is so taken with this astronomical display:

No way, Jose. I want to believe.


Touchdown on Mars

Here’s something you don’t see every day: The Rover’s eye view of landing on Mars.

Four photos per second snapped by the Mars Descent Imager.

Somebody took the photos, made them full-screen, and smoothed the video out:

And as for just where the rover touched down, as of today, it’s called Bradbury Landing:

journalism, science

What It Takes To Write About Science: A Lehrer Lesson

The whole Jonah Lehrer thing just keeps unspooling, yielding a trove of new insights, or presumed insights, or see-how-these-details-fit-what-I’ve-said-all-along insights. Lots of insighting.

It’s sparked some soul-searching (ahem, navel-gazing) among the media about just what it means to be a noble, truth-seeking writer or reporter who focuses on science.

One obvious conclusion:

What we need are not journalists and popular writers who turn their hand to science, but scientists who turn their hand to journalism and popular writing.

That, from a scientist. And another obvious conclusion, from a journalist:

This is what happens when journalists major in neuroscience instead of #journalism.

So, that’s settled.

science, video

Time Dilation with Carl Sagan

Google street-view mock-up of final scene of The Planet of the Apes.

Image created by Brook Boley

Remember the scene where Charlton Heston finds the remains of the Statue of the Liberty? In The Planet of the Apes, I mean. Sorry, I just gave the ending away. It’s a classic trope (the “Earth all along“). And it’s a classic pop culture reference to time dilation.


I recently ran across Carl Sagan’s explanation of time dilation, the phenomenon in which perspectives of time can vary–the concept of relativity that Einstein laid out. The most famous example being the relative slowing of time as you move faster—basically, the reason why Charlton Heston’s mission aboard the Icarus was 18 months for him but more than 2000 years back on Earth, during which time apes evolved, learned English, and took over.

Relative velocity isn’t the only cause of time dilation, but it’s the one Carl Sagan discusses here. The other big factor is gravity—the closer you are to a major source of gravity, like a planet, the slower time passes for you relative to objects farther from the planet.

This is from episode 8 of Sagan’s famous Cosmos series (which I’ve never actually seen). I like the pastoral Italian setting, and especially the opening scene in which Sagan uses a near-collision to illustrate his first point about the speed of light. And while the time dilation thought experiment has a certain poignance, I love the way Sagan supercharges his pronunciation of the Italian names Paolo and Vincenzo. He sounds more Italian than the Italian kids.


[Photo illustration by Brook Boley from Gizmodo’s “50 of the Most Insane Things Never Seen on Google Street View“]

journalism, science

Freeman Dyson and the Great Big World

Freeman Dyson is a global warming skeptic. This should not come as a surprise.

the cover of the new york times magazine with portrait of dysonLast Sunday, the New York Times Magazine featured a profile of the physicist, now in his 80s, as its cover story. He’s been ensconced at the Institute for Advanced Study for the last several decades.

I liked the piece. There are some questions, which I’ve heard a couple of editors express, about why he merited such a long profile, and the cover, no less. But that’s really a question of editorial inclinations.

The great strength of the article is the sensitive portrayal of Dyson himself. He is a character, a charming and sweet man whose life experience reads like fiction. Nicholas Dawidoff, who wrote the piece, describes Dyson’s smile, and his laugh, “so hearty it shakes him,” which is absolutely true. The global warming controversy seems secondary, though I’d guess it was originally the big reason this story was picked up by the magazine. Ultimately, we have this story of a man who is happy with his life, and has always done whatever suited him, rather than whatever the establishment expected. After all, he did switch from being an Englishman to being an American, and from mathematics to physics to activism and writing.

I interviewed Dyson almost nine years ago, in April 2001. As the years pass, I keep thinking how fortunate I am that my first in-depth, sit-down interview with anyone was with him.

You can see a kind of blueprint for the magazine story in my interview, from the series of Dyson’s greatest hits of applied scientific craziness (Project Orion, the so-called Dyson sphere, major genetic re-engineering), to his deep sense of humanity and obligation to the less fortunate.

I was also introduced to Dyson’s skepticism in that interview. He criticized people who were wary of genetically modified foods. He applauded gentrification. He recounted a story about NASA’s emphasis on public relations over science. He dismissed sustainability, “because what does it mean?” As far as Dyson was concerned, “sustainability” was—and, one could contend, still is—vague enough to mean whatever its promoters want.

You can download my interview, conducted for the Dartmouth Undergraduate Journal of Science, as a PDF here.

At the bottom of my web site, in the footer section, there is a phrase: “It is a great big world.” After my interview with Dyson, as I was about to leave, Dyson told me about flying to China, and sitting next to a boy who spent most of the trip staring out the window. At one point, the boy turned to him, and said, “It’s a great big world!.” Indeed, it is. Easy to forget.

journalism, multimedia, science

Night of the Planet Hunter

Geoff Marcy is a Berkeley professor of astronomy and, in little more than a decade, his research team has discovered about half of the known planets outside of our solar system. I sat in with him one night this fall as he used the Keck telescope to scan nearby stars for planets. The result is a four-and-a-half-minute(!) audio slideshow in which he explains his work and how he got started in this somewhat unusual field.

artists's conception of 55 Cancri solar system

The piece is called “California Goes Planet Hunting,” and was produced for California magazine’s recent astronomy issue.

Artist’s conception of the 55 Cancri system courtesy NASA/JPL-Caltech and W. M. Keck Observatory.

articles, science

Oh My Lucky Star

This was fun to report. A short article, called “Lucky Star,” is out in the new California magazine about astronomer Maryam Modjaz and her work documenting a supernova. The twist was that, through a bit of good luck, she and her colleagues had telescopes pointed at it the whole time–before it even exploded.

In the image below, we see three shots of the galaxy NGC 2770. The typical spiral galaxy might have one supernova in a century; this one has had three in the last ten years.

image of galaxy as supernovas pop up as pinpoints of light