45P-ids 2025: prediction of activity
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Fig. 1. Space-temporal projection of 45P-ids trails parts onto their minimal distance passages in 2025 (correspondence between colours of the particles and their ejection velocities can be seen here).

Fig. 2. Detailed space-temporal projection of 45P-ids trails parts onto their minimal distance passages around the time of possible activity from the 1948 trail.

On 8 August 2025 at 13:49 UT the Earth is expected to encounter the trail of the comet 45P/Honda-Mrkos-Pajdusakova ejected in 1948. The parameters of encounter are following: minimum distance is 0.00382 AU, ejection velocity is -11.12 m/s, trail density is 45.9% of that for 1 rev. Leonid trail. These parameters are not very favorable for significant outburst, in particular rather large distance to the trail and quite high negative ejection velocity mean that chances for notable activity are not high. Nevertheless observations are recommended to check what happens. Computed radiant is RA=325.4°, Dec=-16.2°.
Fig. 3. The Earth as seen from coming 45P-ids meteors (RA=326.8°, Dec=-15.1°) during the expected maximum time of outburst from 1948 trail at 13:49 UT on 8 August.

In case the expected activity occurs at the expected time it should be visible very well in Australia, Indonesia, New Zeeland and other island territories on the major part of the Pacific ocean. Less favorable conditions because of lower radiant altitude will be in regions adjacent to south-eastern coast of Eurasia. Unfortunately the full Moon will create significant light pollution during the whole night and sufficiently worsen observing conditions.


1. "Comet's dust 2.0" program by S. Shanov and S. Dubrovsky. [Used for orbital computations.]
2. E. Lyytinen, T. van Flandern "Predicting the strength of Leonid outbursts", 2000, Earth, Moon, and Planets, P. 149-166.
3. Jenniskens P. Meteor showers and their parent comets, 2006, 780 p. 4. Kasuo Kinoshita, http://jcometobs.web.fc2.com/ [Orbital elements of the comet 45P Honda-Mrkos-Pajdusakova]
5. Hewgill G. Xearth 1.1.0 (Software program), 2003.