WHAT: Extinction by the dustlayer from an impact or a volcanic eruption and the recovery of the living organisms.

WHY: We would like to know what has happend to the Earth or could happen in the future to this planet and maybe other planets. After each six major extinctions undergone by Earth, there was a life explosion, e.g. the so-called cambrian explosion. The knowledge of the timescale associated with this life explosion is a key parameter entering in theories of Earth's life evolution.

HOW : By observing the recovery of life after the explosion on the lab scale to the absorpting dustlayer. The experimental setup would be the following:

1. a transparent box below a luminous source, with an artifical ecosystem (plants, micro-organisms, small animals,...) inside and an atmospheric-like circulation controlled by a vertical temperature gradient leading to large-scale convective motions (i.e. a troposphere).

2. at time t=0, we introduce in the upper part of the atmosphere a layer of dust which we control the optical depth and then the absorption properties.

3. we record the life activity (aerobic and anaerobic bacteria, biomarkers like amino acids, activity using labelled carbons...) to achieve the time interval required to reach the similar initial life activity by altered lifeforms and how different these organisms will be.

4. we win the future Nobel prize. Please book now your room in Stockholm.