Right on time for the Asteroid Day - 'a perfect calculation' by the Finnish researchers

29.6.2018
Analysis of the recent 2,8 kt impactor lead to prompt meteorite recovery.

First meteorite fragments were recovered in Russia after thorough analysis of the exceptionally large recent fireball striking the sky over the Lipetsk region in Russia on June 21, 2018.

The total impact energy of the fireball was estimated at 2,8 kt, thus making it a rare case with a less than once in a year occurrence.

Fireball  was widely observed from many places in Russia, including Moscow

fireball Lipetsk region in Russia on June 21, 2018

Photo of the Fireball: link to the original video

The scientists from the Finnish Fireball Network, University of Helsinki, and the Ural Federal University formed a consortium enabling unprecedentedly quick prediction and the actual discovery of the strewnfield on the ground - the area where the meteorite fragments were dispersed following intense fragmentation of the object during the steep atmospheric entry. The fireball  was widely observed from many places in Russia, including Moscow.

After careful consideration, three occasional video records of the fireball were selected for detailed investigation. Collection of the observational data and trajectory analysis were done by Esko Lyytinen, Maria Gritsevich, Nikolai Kruglikov, and Mikhail Larionov. The derived parameters, characterizing the trajectory  were clearly indicative of a number of survived meteorite fragments landing on the ground. Using these results a comprehensive modeling of the strewn field providing the expected locations of the simulated fragments was done by Jarmo Moilanen. With the support of these data meteorite recovery campaign was initiated by Victor Grokhovsky.

The members of the first expedition were Aleksander Pastukhovich and Grigory Yakovlev, who recovered the first meteorite fragment already on Monday, June 25, 2018 in excellent agreement with the predicted results.

Asteroid Day  June 30

“Such collision of Earth with the asteroid occurred just prior to the Asteroid Day stresses a necessity to improve current capabilities of tracking hazardous space objects prior to their intersection with Earth, to be also coupled with forecasts of regional environmental consequences occurring due to their entry”, says Maria Gritsevich, Docent in Planetary Sciences at the University of Helsinki.

It is widely accepted by the scientific community that near-Earth object (NEO) impacts represent a long term global threat to the collective welfare of humanity. Such impacts have occurred much more frequently in the past. Earth would be heavily cratered if it did not have its geologically active lithosphere, and the atmosphere that effectively shields the planet from all but the larger meteoroids and asteroids.

“Solving a problem of estimating risks associated with low-probability high-impact bolide events is often decisionally postponed due to the lack of evidence that such impact would occur ‘soon’ – if so, there considered to be no necessity to map it in the next years of global political and economical developments. However, while the likelihood of a globally threatening event is low, the mathematical expectation (i.e., the product of the probability of the occurrence of an impact and the cost associated with its occurrence) is realistic due to the catastrophic consequences caused to the entire ecosphere”, Maria Gritsevich says.

“This is not a first time when our collaboration lead to overwhelming success – 4 years ago the famous Annama meteorite became a well-deserved result of a similar joint effort”, Professor Victor Grokhovsky from the Ural Federal University says.

Asteroid Day at Helsinki Observatory 30.6.2018 (12-18)

More details:

Maria Gritsevich, PhD, Docent in Planetary Sciences
Email: maria.gritsevich@helsinki.fi
Phone:  050 314 9429

Esko Lyytinen, Lic.Phil., Finnish Fireball Network
Email: esko.lyytinen@jippii.fi
Phone: 0400 900 456

More about the subject: Science