IOTA Occultation Campaigns

Each year IOTA will identify at least two occultation events in North America as special observing campaigns for the year.  One event will be chosen for the potential to generate the most valuable results, and the other event will be chosen as the most “observable”.  We encourage IOTA observers to put these events on their calendar.  Given the high priority for these events, we expect some observers will travel to observe these events. Prior to each event, someone in IOTA will post messages to the IOTA discussion group informing everyone of the weather prospects and possible preferred locations for observers.

Due to the pandemic, there were no IOTA Occultation Campaigns in 2020 and none proposed for 2021. The expectation is that IOTA Campaigns will begin again in 2022, once the pandemic restrictions are gone.

Other Campaigns

Special events, most requiring considerable experience in occultation observing, are being observed in a coordinated fashion. Some are announced on the user group forums, but others are with self-selected observers who are known to the individual coordinator as able and willing to observe. These include occultations by asteroids of critical importance for upcoming spacecraft missions or asteroids which have a potential for Earth impact.

(99942) Apophis Occultations

A recent example has been the campaign to observe the occultations by the asteroid (99942) Apophis in its current passage close to Earth. Apophis is small, but important as it will pass very close to the Earth in 2029 and 2036, with a very small chance of impact in 2068.

All of the events predicted for North America for 2021 have occurred. David Dunham posts descriptions of the Apophis occultation observing results and plans for upcoming events here.

A presentation on NEO occultations which includes summaries of the Phaethon and Apophis expeditions is in preparation, updated as results are made available. Found here, this is for a general audience not expected to be familiar with occultations; the Phaethon and Apophis discussion begins on Slide 19.

Lucy Mission Support

A series of events to support the upcoming Lucy spacecraft has been ongoing under the direction of Marc Buie of SWRI. Experienced IOTA members have supported these campaigns and will continue to do so, especially for those events of brighter stars in North America. On Oct 20, a 13th magnitude star will be occulted by (3548) Eurybates with the predicted shadow path crossing the entire United States, but only observable from California, Nevada, and Arizona due to the rising Sun. A SWRI expedition is planned with participation by IOTA members. See . The signup form is at .

The website has details of the past and future occultations by all of the Lucy mission target asteroids.

Contact IOTA via the Secretary/Treasurer at the address given on the contact page if you would like to inquire more about the events described on this page or about observing in a campaign.

These special campaigns are generally not announced well in advance so they will not be promoted on these pages. However, well-qualified and interested observers are encouraged to communicate with the IOTA Officers or Secretary/Treasurer if they would like to be included in these campaigns. Please do note that these events are often near the limit of possibility using the portable telescopes and moderately-priced video equipment most of the observers have.