NASA to discuss science findings of Mars comet flyby

Our colleagues at NASA have announced a media briefing at 18:00 today to discuss initial findings from the 19 October comet Siding Spring flyby. Original post below, including links to webcast.

NASA will host a media teleconference at noon EST on Friday, Nov. 7, to provide initial science observations of comet C/2013 A1 Siding Spring’s close flyby of Mars and the impact on the Martian atmosphere.

NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft, Mars Reconnaissance Orbiter (MRO), and a radar instrument aboard the European Space Agency’s Mars Express spacecraft provided the first close-up studies of the comet that originated from the distant outer reaches of our solar system.

Briefing participants include:

- Jim Green, director, Planetary Science Division, NASA Headquarters, Washington

- Nick Schneider, instrument lead for MAVEN’s Imaging Ultraviolet Spectrograph, University of Colorado, Boulder

- Mehdi Benna, instrument scientist for MAVEN’s Neutral Gas and Ion Mass Spectrometer, NASA Goddard Space Flight Center, Greenbelt. Maryland

- Don Gurnett, lead investigator on the Mars Advanced Radar for Subsurface and Ionosphere Sounding instrument on Mars Express, University of Iowa, Iowa City

- Alan Delamere, co-investigator for MRO’s HiRISE instrument, Delamere Support Services, Boulder, Colorado

For dial-in information, media representatives should e-mail their name, affiliation and telephone number to Dwayne Brown at by 17:00 CET Friday.

Visuals will be posted at the start of the event at:

Audio of the teleconference will be streamed live at:

The event will also be streamed, with visuals used by the participants at:


Comet Siding Spring imaged by HRSC on board Mars Express

Comet Siding Spring came extraordinarily close to Mars as it whizzed by on 19 October 2014. The celestial body – a mere 500 metres in diameter – passed the Red Planet at a distance of just 137 000 kilometres, where it was observed by several spacecraft in orbit around Mars. The High Resolution Stereo Camera (HRSC), operated by the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) on board ESA's Mars Express, also acquired a series of images with its SRC channel during Mars Express orbit 13710.

This animation combines multiple images that were acquired by the HRSC camera on board Mars Express during the comet Siding Spring flyby on 19 October 2014. Credit: ESA/DLR/FU Berlin

This animation combines multiple images that were acquired by the HRSC camera on board Mars Express during the comet Siding Spring flyby on 19 October 2014. Credit: ESA/DLR/FU Berlin

As it flew by, Siding Spring was travelling at a velocity of around 56 kilometres per second relative to Mars. Images were acquired at 17-second intervals; the spatial resolution is 17 kilometres per pixel. The images show the comet nucleus as well as the surrounding dust and gas cloud (coma).

Comet Siding Spring originates from the Oort Cloud, a comet ‘reservoir’ in the outer reaches of the Solar System. The comet was named after the Australian Observatory at which it was originally discovered back in 2013, and has the scientific designation C/2013 A1. As comets approach the Sun, one or two tails composed of gas and dust or ionised gases form on the side facing away from the Sun. As it whizzed by the planet, Siding Spring’s tail penetrated the Martian atmosphere, where it was analysed by the particle detector ASPERA-3 on board Mars Express, among others.

Scientists hope to use the data acquired, as well as the spectrometer measurements conducted at the same time, to gain an insight into the comet’s composition. It is thought that comets may contain material dating back to the formation of the Solar System.