the SCIENCE of the

SOLAR SYSTEM

SciSolSys

Planet Party

SciSolSys Planet Party

How do you organize a space party? You planet!

by Lori Dajose

 

It’s a tradition that every great astronomer has diligently followed. It’s a necessity that every curious researcher has built a career upon. Peering up at the universe through a telescope is the crucial cornerstone for planetary science and astronomy. Tonight, the Ge11c class at Caltech is participating in this age-old practice with Caltech’s MINERVA telescope, led by project manager and postdoc Jon Swift.

 

You can tell Jon has been doing this for a while—his seasoned manipulation of the telescope controls illustrates how much time and effort he has invested into this planet-hunting eyeball—but from his enthusiasm, you’d think it was his first day on the job. He explains to us that MINERVA’s goal is to use radial velocity measurements to find planets, and if possible, obtain a light spectrum from the planet’s transit. We’re all a bit skeptical—after all, we’re in the smog-bowl of Los Angeles County, and we can barely see stars, let alone exoplanets! Jon understands our doubt, and uses it to astound us: the telescope is so powerful, it can actually see stars bobbling down to a speed of 1 meter per second—otherwise known as walking speed.

 

But tonight, we’re just using MINERVA as a good old Galilean eyeball on our own cosmic neighborhood: the solar system. Mars and Jupiter are both out, and we start with Jupiter.

 

Now, being a planetary science major, you learn a lot about the planets. You learn about the physics that allowed Jupiter to accrete such an enormous size, about the fluid dynamics that governs its storms, and about its lovely little alien moons which squeeze and expand with tidal forces. I’m always fascinated when we learn about planets.

 

Tonight is different. Tonight we are no longer in a classroom; we are returning to the core of astronomy: looking upwards. And I am completely unprepared for the way MINERVA magnifies the magnificent planet I have been learning so much about. Jupiter is breathtaking. The orange and white stripes are clearly visible, along with two specks of moons. The image swims because of atmospheric effects, but every few minutes or so you get lucky and the stripes resolve themselves—a pattern of enormous storms, beauty in tumultuous physics.

 

Jon swings the telescope around, and next up is Mars. (I think Percival Lowell is probably rolling around with anguish in his grave, because I’m spotting no Martian canals.) The red planet stays absolutely true to its name, and it’s a slightly-fuzzy brown-orange blob. It has particular significance for me, as this summer I’ll be using a Mars simulation chamber to study the iron oxidation on Mars that causes its distinct red color. It’s one thing to study Mars in a chamber in a basement of a lab, but it’s quite another perspective to absorb its photons with your own eyes.

 

Next, after admiring the detailed shadowy craters on the Moon, and a dusty-looking smattering of stars that make up the dense M3 globular cluster, the conversation turns theoretical—to things we can’t see.

 

“Go out into some dark place, and look up,” Jon tells us, “Not one of those stars you see is an M-dwarf.” This is because M-dwarfs, or red dwarfs, are small and dim. But though they’re little, they’re certainly not underrepresented—these subdued stars make up 75% of all the stars in our galaxy, and hold a majority of the mass. They’re also the most likely to host planetary systems. In a recent paper Jon and his colleagues published, they estimated that there’s an average of two planets per star in our galaxy. This comes out to a conservative estimate of hundreds of billion planets. Hundreds of billions of unseen worlds.

 

And yet, we haven’t found one that’s inhabited. Statistically, there should be some sort of life elsewhere on the multitude of planets in our Milky Way, and some of that life should be intelligent and complex.

 

“So, where is it?” Jon asks. The galactic silence is a bit unnerving. Perhaps it implies that intelligent life doesn’t last very long—that there’s some sort of “great filter,” which most species never make it past. It makes us wonder: are we the lucky ones that have survived to evolve higher and higher, or is the ominous great filter looming in front of us?

 

But, just because we haven’t found anything doesn’t imply that we’re destined for either loneliness or extermination. We can take a bit of comfort in the fact that we don’t really know what we’re looking for, anyway. We assume that the building blocks of life and the principles of evolution are homogenous across the universe, but in reality, alien life beyond our imagination could be staring us in the face.

 

“We should not confuse the limitations of our own tiny intellects with limitations on the creativity of Cosmic Evolution.” — David Grinspoon, Lonely Planets

 

So our planet party ends in an awestruck and humble silence, each of us musing over our place in this grand universe. Looking up tends to do that to you.

 

On Traditions and Telescopes

words and photos by Alec Brenner

 

Being at Caltech involves a lot of fun traditions, not the least of which is Ditch Day. This year, Ditch day took place on Thursday, May 15, so class was canceled… and I was supposed to blog about it. I could have written about Ditch Day, but in the end that all boils down to puzzles, nerf gun fights, and taping seniors to trees. I’m going to write about something a little different.

 

Being at Caltech also involves having access to a lot of pretty amazing resources. On the night of Monday, May 12, our Ge11c class got to use one of them. Caltech has its own in-house astronomical observatory, a pair of telescopes in the MINERVA array. Naturally, as a photography nut, I brought my DSLR with me, eager to get some great images of the planets.

 

We walked to the observatory structure – basically an oversized, fancy-looking metal shed – and met Dr. Jon Swift, the postdoc who would be operating the telescopes for us (a big thank-you to Jon for letting us use the observatory!). Jon clambered into the observatory and pushed a button, and slowly but surely the two segments forming its roof swiveled aside.

 

 

 

 

 

 

 

 

 

 

 

 

 

Two shiny 0.7-meter telescopes appeared, along with a suite of monitors and controls for operating them. Jon elaborated: “These are state-of-the-art, dual Naysmith-focus telescopes – they’re eventually going to be put on top of Mt. Hopkins in Arizona to do dedicated exoplanet surveys using radial velocity [techniques].” Pointing to a protrusion from one telescope, he said “this is the eyepiece we’ll be looking through tonight, and on the other side…” as Jon shifted around in the cramped observatory structure, “…is this module – it’s basically an $80,000 camera.” I looked down at my own consumer-level DSLR and 500mm lens, and it didn’t seem so fancy anymore.

 

After giving us a more detailed tour of the telescopes, Jon fiddled around at the controls, and telescope quickly oriented itself at an already-bright dot westward in the dusk sky: Jupiter. One by one, we shuffled in to get an eyeful of the gas giant we’d written so many equations of state for, to actually witness it in-person. I could describe it here in excruciating detail, but I pointed my DSLR into the eyepiece and took photos, so I’ll let one of the photos do the talking:

 

 

 

 

 

 

 

 

 

 

 

 

You could see Jupiter’s two main dark bands, plus two of its moons (Europa is the dot below Jupiter in the photo, and Io is just out of my image, above Jupiter). To bring out some of those details better, I’ve included a post-processed image (also above) with annotations. Also interesting was that you could actually see the atmosphere blurring the image in real time – most of the time, Jupiter looked like it was behind a lot of “heat haze,” but every once in a while, if you were lucky, the haze would die down a little for a fraction of a second, exposing incredible detail in the band system.

 

 

 

 

 

 

 

 

 

 

 

 

Jon explained that astronomers like him take advantage of those fleeting glimpses of relative clarity by taking tons of photos in rapid succession of something they’re observing. The hope is that a few of them captured clear moments, and these can be combined to make even clearer images. This process is appropriately called “lucky imaging.” As it turns out, the atmospheric blurring around Pasadena is pretty crummy, and that night was actually one of the best Jon had worked with in a while.

 

But we’d had enough of Jupiter, so we moved on to look at a bright reddish dot high in the south – Mars. Again, we all looked at Mars, and this time, I tried my hand at the “lucky imaging” technique. The results did not disappoint:

 

[image]Most of the time, if you looked through the telescope, Mars was a very bright, featureless, reddish disk. But every once in a while, a little white dot would show up on the bottom of the planet – the north polar cap! I clearly saw the polar cap in just a few of the ~20 images I took through the lens of the telescope, and it’s really easy to see in the contrast-enhanced version of the photo above.

 

It was neat to think that all of the crazy surface features, atmospheric chemistry, and rovers we’d been talking about at length in class were all there. You could look up in the sky with the naked eye and see Mars, of course, but to look at it with a high-powered telescope and be able to prove that it was the planet we’d talked about so much – that was something else.

 

We had to move on at some point though, so we turned the telescope to the full Moon. After a quick change of eyepieces, the telescope was ready to go, and we all looked intently at the Oceanus Procellarum region of the lunar surface. As usual, here are the images:

 

 

 

 

 

 

 

 

 

 

 

 

Again, we moved on, this time to Saturn. We all looked at the expansive, bright ring system, as well as Saturn’s biggest moon, Titan (way off to the right of the planet in the photo – it just barely shows up above the noise in the contrast enhanced version).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

As for the planets, that was it – no more were up that night. Jon treated us to a view of globular cluster M3 (I did not get a photo of this exceedingly faint object), and took a photo with his powerful CCD camera of the Whirlpool Galaxy, M51. Sadly, we couldn’t really see much else, as the sky from Pasadena is incredibly light-polluted. (For great views of the sky, of course, there’s the empty desert, like in the below photo of the Milky Way’s core that I took from the Salton Sea.)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

But for now, back to a Ditch Day – there’s a nerf battle to fight. (Let’s face it, we’re all five-year-olds inside…)