Antarctica 2018: Chapter 12: What is LANDIT, and why does it need the South Pole?
Link to Chapter 11: Work at the South Pole.
Link to Chapter 10: Thank you, friends.
Link to Chapter 9: At the bottom of the world
Link to Chapter 8: Onward, Southward!
Link to Chapter 7: Exploring McMurdo Station
Link to Chapter 6: Touchdown Antarctica
Link to Chapter 5: Flight Day!
Link to Chapter 4: ECWs
Link to Chapter 3: Christchurch!
Link to Chapter 2: Auckland
Link to Chapter 1: From Hawaii to Antarctica
So why am I in Antarctica, and at the South Pole, anyway?
The program that I’m the resident Principal Investigator for is called LANDIT: The Long-Duration Antarctic Night and Daytime Imaging Telescope (LANDIT). It’s a joint program between the Air Force Office of Scientific Research and the National Science Foundation Office of Polar Programs.
Now that you know a bit of the background, there’s two important things to remember:
The more spherical harmonic modes you can determine for an object (whether that object is a star, the Sun, or a giant planet like Jupiter), the better defined are its interior and surface — and that’s what we care about.
From the above, there’s just one thing you should take away: intrinsic oscillations modulate emergent flux. What that means is: things happening on the interior affect the oscillations in brightness on the exterior. And those oscillations in brightness can be measured with a telescope.
Aha! Enter LANDIT. We can measure light coming from a body (again, the principle is the same for stars, the Sun, or a giant planet), measure changes in that light, then invert into the power domain to try and extract modes of oscillation.
Below is an example from the field of astroseismology. The near observed modes, as spikes at specific frequencies, is the product we are looking for… but for Jupiter.
So why Jupiter? What do we learn from applying these techniques to Jupiter (other than learning about the interior structure of our solar system’s larger planet)?
Of course, I’m not the first person to think of this. Others have been trying since before I was born to try and detect modal oscillations on Jupiter, as seen below. Here’s what you need to keep in mind: signal to noise ratio. No one has been able to get a strong enough signal to create the nice neat plot you saw above for astroseismology.
And this is where the South Pole enters the picture.
That’s right! One day, one night, per year: that’s the South Pole, and it’s the only place on Earth where Jupiter will be above the horizon, continuously, for over 100 days, just circling the cold night sky above the bottom of the world. Our idea is, essentially: that’s how we beat the signal-to-noise problem. Continuously observe Jupiter for months at a time, without non-random interruptions. Anywhere else in the world, the Sun interrupts your observations every 12 hours. Not so at the Pole!
And that’s why I’m at the South Pole today. LANDIT is a long project: we need to build up the engineering expertise to field an optical telescope at the South Pole. There are no optical telescopes at the South Pole today, and that’s because maintaining a constant temperature above freezing for a telescope is extremely hard.
So the project is set up in phases. The first phase is underway right now.
Which brings me full circle back to 2018! Perhaps now some of the images of me at work near SuperDARN will make more sense…
Just to give you an idea of how complex things can get for an optical telescope in the harsh environment of the South Pole… the LANDIT 2018 telescope is tiny, and purchased off-the-shelf — in direct comparison to the LANDIT 2019 telescope, which will be significantly larger and more complex. This is a picture of the systems diagram, with all the modifications [thermal and other] that had to be made to allow the 2018 telescope to be fielded.
Antarctica isn’t easy!
LANDIT has many engineering and scientific challenges up ahead. But our hope is to pull off the first-ever 100 day observation campaign on any solar system object. And in doing so, learn something about our largest neighbor and the formation of our solar system!
Not bad, eh?