The WT1190F observation campaign

23 December 2015

The impact of WT1190F in the Indian Ocean on 13 November (see our news item on 22 October) provided an excellent opportunity to simulate the observational sequence that needs to be triggered if an actual asteroidal impactor were discovered.

The NEOCC has contributed to ensuring that extensive ground-based observations took place.

Astrometric data were obtained by the ESA Optical Ground Station telescope, the Mauna Kea observatory in Hawaii and the INAF (National Institute for Astrophysics) Asiago observatory in Italy from very early after discovery to less than an hour before the impact. Later observations, up to the hours before impact, were obtained by Loiano, Lumezzane, the Schiaparelli Observatory and the newly-established DeSS (Deimos Surveillance Sensors) in Spain.

Extremely valuable precovery observations have been located in the Pan-STARRS (Panoramic Survey Telescope & Rapid Response System) archive, which extended the observed arc as far back as September 2009, thus establishing that the object was already in Earth's orbit at that time.

The INAF Loiano and Asiago Observatories obtained colour data of the object as well as an extended observational coverage to investigate the possibility of long rotational periods.

Spectroscopic observations have been carried out using the Very Large Telescope of ESO (European Southern Observatory), which convincingly proved that the object was indeed artificial.

A spectrograph has been flown during the International Astronomic Center /United Arab Emirates Space Agency/NASA/ESA-sponsored an airborne campaign in order to observe the object's re-entry from an airplane flying over the impact area.

This impressive coordinated effort could not have been possible without the enthusiastic support of many people and observatories; in particular of Bill Gray for the precovery searches, Peter Jenniskens, Mohammad Odeh and Stefan Loehle for the airborne campaign.

Image: instrument flown during the airborn campaign. [Credits: IAC/UAE/NASA/ESA S.Loehle].