On Top of the World - A Visit to Mauna Kea

Earlier this year I was one of 18 educators selected for 2023 to be in the NASA/SETI Institute Astronomy Activation Ambassadors program. It focuses on teaching hands-on methods for teaching about multi-wavelength and especially infrared astronomy. Along the way we've had lots of training which included an online course to complete, a bunch of Zoom meetings and lots of emails. All of this culminated in an intense week of curriculum training and a visit to the Mauna Kea Observatories, specifically to get a first-hand look at NASA's Infrared Telescope Facility (IRTF). 

I'm not going to focus on the curriculum training here (that's for my students to experience), but instead on the visit to Mauna Kea Observatory. I've been to Mauna Kea before (and blogged about it here!), but it was many years ago and this visit offered so much more. I made this return trip with great reverence and a profound appreciation for what this special place means both to the Hawaiian people and the world of astronomy.  

That's me on Mauna Kea with the domes for the Subaru (left) and Keck Telescopes in the background.

After first spending time at the headquarters for the Gemini Observatory and the Institute for Astronomy in Hilo we prepared for our visits to the observatories by spending time at Hale Pohaku, the astronomers quarters, at the 9,300 foot level of Mauna Kea. This allowed us not only to acclimate to the elevation, but to take in its breathtaking night sky. 

The Milky Was so brilliant that you didn't need to be dark adapted at all to see it. Here's a photo of it that I captured with my iPhone:

The summer Milky Way as seen from Hale Pohaku, Mauna Kea

The Milky Way and its spectacular dust clouds were beautiful. It is a shame that because of light pollution most people in the world never get to see it (even fewer see it from such an amazing site as this one!). Of special interest to me are the two stars near the bottom of the image.  The one on the left is Alpha Centauri, the famous Sun-like star that's just 4.3 light years from Earth. To its lower right is Beta Centauri, also known as Hadar, a blue giant star located 90 times further away. Both of these bright stars are too far south to see from my home in Southern California, so catching them was a special treat.

The next day we made a daytime visit to the summit and got our first close look at NASA's IRTF. Fun Fact: the IRTF was built to help support NASA's Voyager missions and made its first infrared observations of Jupiter just before Voyager's first flyby.

Here's the dome of the IRTF:

Behind the IRTF is the Pacific Ocean and the island of Maui. Inside is a 3.0-meter reflecting telescope:

The view above looks up to the telescope's secondary mirror. Most infrared telescopes have an undersized secondary mirror to avoid reflecting any of the heat of the telescope itself to the science instruments. 

When the telescope points at the astronomical object being studied infrared light reflects off of its primary mirror, to the secondary mirror and then down to the Cassegrain focus underneath the main mirror where one of the science instruments collects the light.

Science instruments in the IRTF's Cassegrain focus.

After our daytime visit we returned to the IRTF that night to sit in on some observing. The targets: debris disks around young stars where planetary systems are forming, then studies of the atmospheres of Saturn's moon Titan and Jupiter's volcanic moon Io. These were all studied using spectroscopy, which provides astronomers with a detailed look at the composition of objects.

We got to the telescope before sunset and what a sunset it was.

Mauna Kea sunset with the Keck telescopes.

Here's the open dome of the IRTF during the 'golden hour':

The view was spectacular looking across the mountain, away from the sunset:

From left to right that's the shadows of the IRTF, Keck I & II and the Subaru Telescope domes. Behind the shadows are the domes of the Canada France Hawai'i Telescope, Gemini North, the 2.2-meter University of Hawai'i telescope and the 3.8-meter United Kingdom Infrared Telescope (UKIRT). Note: the UK no longer operates UKIRT. 

Nature put on its own show after sunset as the Moon, Mars (left of the Moon) and Venus (just above the dome) were out in the western sky:

After it got dark and the scientific observations were underway at the IRTF I captured its dome against the starry backdrop of the summer Milky Way:

Looking the other way, the Keck Observatory was making use of its adaptive optics laser guide star:

While we were there the observing program using the laser guide star at Keck was headed up by Andrea Ghez, who won the 2020 Nobel Prize in Physics for her studies of the stars orbiting the supermassive black hole at the center of the Milky Way Galaxy. The observing here was a continuation of that research and we could see that the laser was indeed pointed toward the center of the Milky Way:

All-in-all it was an amazing night that culminated in our having some conversations with the astronomers who used IRTF. They needed to be focused on the work at hand while they were observing, so speaking with them afterwards was the way to go so as to not get in the way of their limited telescope time.

The next day we were given a daytime tour of the James Clerk Maxwell Telescope (JCMT). The Observatory is also on Facebook. Find it here.

The JCMT observes at wavelengths that are longer than infrared, but shorter than radio waves in the submillimeter part of the electromagnetic spectrum. As such, it looks a lot like a big radio dish antenna:

The JCMT is one of the telescopes that make up the Event Horizon Telescope that was used to produce the first image of a supermassive black hole (in the galaxy known as M87). It has also been used to detect phosphine in the atmosphere of Venus, which *may* suggest the possibility of bacterial life in its atmosphere (at very best its presence is unexplained).

Daniel Chase, me, project P.I. Dana Backman, Mark Lenfestey, and Vikini Santhanakrishnan underneath the JCMT. Photo by Callie Matulonis.

A big thank you to Callie Matulonis for giving us such a great tour that served as a wonderful capstone to an amazing week of astronomy that has had a huge impact on me personally and will carry over into my teaching in many ways.