NG Field Notes: Pluto-Chasers Warm Up in Majuro

The following is updates from Cathy Olkin on the current NG-sponsored field campaign, funded in part by NG, to capture an occultation of Pluto and its moons.  -V


Update from Majuro 6/23 local time: We have a replacement declination drive part that would help the team on Nauru with the gears that broke in the shipment of their telescope. We tried this morning to see if there was a way to get the parts to Peter and Larry on Nauru by Monday for the second occultation. We tried a local shipping company, the post office and Air Marshall Islands. There doesn’t seem to be a way to get the part from this island to Nauru.

This afternoon we decided to consider a changing one setting on our camera to reduce the noise in our data. We were going to use a slower analog to digital converter (ADC) rate. Before using it tonight, we wanted to test it “in the lab.” In this case, “in the lab” means in my hotel room. Unfortunately when we changed the ADC rate from one value to another it causes camera to not work at all – we get a signal level of zero in all pixels. We tried to understand what causes the problem, but time is running short. We will just be using one ADC rate all night and not try to change that setting. We are running a 30-minute test right now to confirm the settings we will be using tonight will work.

Hopefully we will have clear skies and little wind tonight for the occultation. Wish us luck!


Update from Majuro 6/22 local time: Jeff Regester arrived yesterday on his way to Kwajalein to observe the stellar occultations. Harold, Jeff, and I set up at sunset yesterday to get some calibration data. In the evening, we saw a beautiful rainbow. Little did we realize the rainbow was our clue that a brief but heavy rain was on its way. We scurried to cover the telescope and equipment with tarps. Once the rain passed, we had partly cloudy skies. We were able to observe the occultation stars at different exposure times to help optimize our data-taking strategy. We will be reducing that data today.


Update from Majuro 6/21 local time: Harold and I arrived yesterday in Majuro [the Marshall Islands]. We were pleased to find that our equipment made it as well.

With the assistance of the folks at the Weather Service Office in Majuro, we were able to move our telescope crate, which weighs about 300 pounds [136 kilograms], to their station.

Harold at the Majuro weather station.

Last night we set up the telescope and camera and were able to record data of the star fields for both the June 23 and June 27 occultation. This demonstrated that the equipment was working fine.

A very good first day!

Harold, the telescope, and a weather balloon on Majuro.

Dr. Harold Reitsema is an astronomer who first observed an occultation in 1973 and has traveled around the world to observe dozens of occultation events for Pluto, asteroids, and planetary rings and moons since. This professional interest is complemented by his passion for observing total solar eclipses, which he has pursued to such places as Egypt, Australia, and Tahiti. He was a designer for Hubble Space Telescope instruments during his career at Ball Aerospace, and he is now pursuing a mission to catalog nearly a million near-Earth asteroids and survey the potential risk to the Earth from a future impact event.

Dr. Cathy Olkin is a planetary scientist at Southwest Research Institute in Boulder, Colorado. She studies cold, icy outer solar system bodies using infrared spectroscopy to learn about their surface compositions and using stellar occultations to probe their atmospheres. She loves a good occultation campaign—the adventure of traveling to remote locations, the challenge of getting high-quality data, and the thrill of learning something new about these remote worlds. She is also a co-investigator on the New Horizons mission to Pluto and beyond.

Changing Planet