English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Comet C/2013 A1 (siding Spring) will experience a high velocity encounterwith Mars on October 19, 2014 at a distance of 135,000 km +- 5000 km from theplanet center. We present a comprehensive analysis of the trajectory of boththe comet nucleus and the dust tail. The nucleus of C/2013 A1 cannot impact onMars even in the case of unexpectedly large nongravitational perturbations.Furthermore, we compute the required ejection velocities for the dust grains ofthe tail to reach Mars as a function of particle radius and density andheliocentric distance of the ejection. A comparison between our results and themost current modeling of the ejection velocities suggests that impacts arepossible only for millimeter to centimeter size particles released more than 13au from the Sun. However, this level of cometary activity that far from the Sunis considered extremely unlikely. The arrival time of these particles spans a20-minute time interval centered at October 19, 2014 at 20:09 TDB, i.e., aroundthe time that Mars crosses the orbital plane of C/2013 A1. Ejection velocitieslarger than currently estimated by a factor >2 would allow impacts for smallerparticles ejected as close as 3 au from the Sun. These particles would reachMars from 43 to 130 min after the nominal close approach epoch of the purelygravitational trajectory of the nucleus.

Trajectory analysis for the nucleus and dust of comet C/2013~A1 (Siding Spring)