Ground Based Observation Working Group

 

Figure: Ground based observations of sodium exosphere over the disk of Mercury (as taken from the THEMIS telescope) superposed to the in situ observation of the sodium tail during MESSENGER flybys (adapted from Mc Clintock et al., 2008).

 

In the frame of the BepiColombo mission, Earth-based observations of the exosphere have a crucial role in complementing the local observations. In fact, in-situ observations will always be very detailed but showing only a partial region of the Hermean exosphere and environment.

Earth-based observation on the contrary are able to provide the global view of the Hermean exosphere, though limited by the distance and by the geometry of the Earth and Mercury position along their orbits.

The role of the Ground Based Observation Working Group is to keep the scientific community of observers updated and linked to the Hermean Environment Working Group (HEWG) which of is a useful complement.

The role of the WG is to promote coordinated Earth based observations of the exosphere during the BC cruise and nominal phases (from now to 2027) and provide the scientific community with high quality data to implement in-situ measurements that will be performed by MMO and MPO devoted instrumentation, and help resolving the open questions on the exosphere generation, interaction and loss.

Starting from 2021, BepiColombo will begin the 6 flybys at Mercury. Coordinated observations are encouraged and welcome.

 

Primary Questions

  1. How does the ground based frequently observed N/S asymmetry (and dawn-dusk asymmetry observed during transits) merge with the MESSENGER results  showing a magnetic dipole offset, global seasonal variations of the exosphere and 'cold poles' enhancements?
  2. How does the (Na) exospheric interacts with the inner heliosphere events and nominal conditions to form the morphology and dynamics observed up to now?

Practical Questions

  1. What are the best suited telescopes and instruments on Earth and orbiting around it that can be used to provide new interesting observations?
  2. Can a new long-term international campaign of observations of Mercury exosphere be organized and supported through the years until Bepi Colombo reaches Mercury?

Meetings (most recent first)

 

2024 OBSERVATIONS

Planned Earth-based observations of Mercury exosphere in 2024 are listed below:

  • THEMIS observatory in Tenerife - Canary Islands (90-cm Ritchey-Chrétien alt-az evacuated telescope) led by Francois Leblanc (LATMOS-IPSL-CNRS, Paris, France): June 27 - July 6
  • THEMIS observatory in Tenerife - Canary Islands (90-cm Ritchey-Chrétien alt-az evacuated telescope) led by Valeria Mangano (INAF, Roma, Italy): September 3-7 (during fourth BepiColombo flyby at Mercury)

 

2023 OBSERVATIONS

Planned Earth-based observations of Mercury exosphere in 2023 are listed below:

  • THEMIS observatory in Tenerife - Canary Islands (90-cm Ritchey-Chrétien alt-az evacuated telescope) led by Valeria Mangano (INAF, Roma, Italy): June 6-10 + June 17-21 (including contemporary observations during third BepiColombo flyby)
  • Haleakala Observatory - Hawaii (60cm telescope): TBC

 

2022 OBSERVATIONS

Planned Earth-based observations of Mercury exosphere in 2022 are listed below:

  • THEMIS observatory in Tenerife - Canary Islands (90-cm Ritchey-Chrétien alt-az evacuated telescope) led by Valeria Mangano (INAF, Roma, Italy): June 21-30 (including contemporary observation during second BepiColombo flyby) + July 28-Aug 6
  • LOWELL DISCOVERY TELESCOPE - Arizona (4.3m)  led by C. Schmidt (Boston University, Boston, USA): TBC
  • Dunn Solar Telescope - New Mexico led by C. Schmidt (Boston University, Boston, USA): TBC
  • 3.5 telescope at Apache Point - New Mexico led by R. Vervack: TBC
  • Io Input/Output observatory (IoIO) - Arizona (35cm coronagraph) led by J. Morgenthaler: TBC
  • Haleakala Observatory - Hawaii (60cm telescope): TBC

 

 

2021 OBSERVATIONS

1) Starting from 2021, BepiColombo began performing the programmed flybys at Mercury. Coordinated campaign of Earth-based observation in support is ongoing.

A preliminary list of the flyby dates with useful observation parameters is shown below (from Mangano et al., SSR, 2021), with the best suited observatories and sites for daylight and twilight observations withing one hour from closest approach time. 

 

Table: List of  the 6 Mercury flybys tobe performed by BepiColombo (as in 2020) with main observing parameters from the Earth (from Mangano et al., 2021).

 

2) Planned Earth-based observations of Mercury exosphere in 2021:

  • THEMIS observatory in Tenerife - Canary Islands (90-cm Ritchey-Chrétien alt-az evacuated telescope) led by Valeria Mangano (INAF, Roma, Italy): Oct 27-Nov 9 
  • LOWELL DISCOVERY TELESCOPE - Arizona (4.3m)  led by C. Schmidt (Boston University, Boston, USA): May 7-14
  • Dunn Solar Telescope - New Mexico led by C. Schmidt (Boston University, Boston, USA): Oct 25-29 
  • 3.5 telescope at Apache Point - New Mexico led by R. Vervack: Oct 24-29
  • Io Input/Output observatory (IoIO) - Arizona (35cm coronagraph) led by J. Morgenthaler: Oct 23-Nov 6 (tbc)
  • Haleakala Observatory - Hawaii (40 and 60cm telescopes): August and September (Tbc)

 

3) Performed coordinated observations in October-November 2021:

 

On October 28 and 29 the all 4 teams had contemporary data at about 12-13 UT.
THEMIS and DST observed the disk; APO and IoIO observed the close and distant tail.

 

 

2020 OBSERVATIONS

1) Planned Earth-based observations of Mercury exosphere in 2020:

  • THEMIS observatory in Tenerife - Canary Islands (90-cm Ritchey-Chrétien alt-az evacuated telescope) led by Valeria Mangano (INAF, Roma): August 28th-Sept 6th (dusk terminator in view and disk at 90%) + October 1st-6th (dusk terminator in view and Mercury in 3rd quadrant of the orbit)  --> NOT PERFORMED DUE TO COVID-19

 

2019 observations & call for observers

1) Coordinated plan of Earth-based observations of Mercury exosphere in 2019:

  • Haleakala observatory in Maui- Hawaii (40-cm Schmidt Cassegrain telescope) lead by Shingo Kameda (Rikkyo University, Tokyo) : April 9-May 7 June 4 - July 11  August 1- August 19   September 24 - November 4 November 20 - December 13   February 2 - February 17  March 5 - April 20  (when Sun-Earth-Mercury angle is 15 degrees)
  • THEMIS observatory in Tenerife - Canary Islands (90-cm Ritchey-Chrétien alt-az evacuated telescope) led by Valeria Mangano (INAF, Roma): October 11-24 (dawn terminator in view and True Anomaly Angle between 170 and 240 - exact days to be confirmed)
  • DCT in Coconino National Forest - Arizona (4.3 m Ritchey-Chretien telescope) led by Carl Schmidt (University of Boston, MA) and Tom Bida : June 10-17 

 

2) Mercury transit in 2019: on November 11th a Mercury transit above the solar disk will occur between 12:35 and 18:04 UT and it will be fully visible in South America, North America (eastern coast) and on the Atlantic ocean, including Canary Islands (see for example: http://eclipsewise.com/oh/tm2019.html).

 

3) An unofficial call is now open to look for new observers of the exosphere of Mercury. Please come and meet us at the next EPSC-DPS meeting in Geneva next September 15-20th, 2019, or contact us via email. 

 

ResourceS

 

contactS

  • Valeria Mangano, INAF-IAPS, Rome Italy: name.surname at inaf.it
  • Carl Schmidt, Boston University, MA, USA
  • Shingo Kameda, Rikkyo University, Tokyo, Japan

Next meetings

Meet us at:

  • EPSC-DPS meeting in Geneva, 15-20 September 2019
  • Mercury 2022 Conference in Orleans (France), 7-10 June 2022
  • BepiColombo SWT in Muenster (Germany), 18-21 September 2023

 

WORKING GROUP CHAIR

  • Valeria Mangano, INAF-IAPS Roma, Italy (email: name.surname at inaf.it)

OTHER INFORMATION