Changes on Mercury detected by Messenger over four year time period
Using archival data collected from 2011 to 2015 while the orbiter Messenger circled Mercury, scientists have located twenty spots on the planet where something changed during that time period. The map to the right, adapted from the paper, indicates those locations. From the paper’s abstract:
We identified at least one change likely resulting from a newly formed impact crater with bright rays that extend away from the site. If all the changes result from impact events, then the present-day rate of impactors striking the innermost planet is 1,000 times higher than models predict. Therefore, we investigate other sources for these detected changes. We located several changes on steep slopes near tectonic landforms, consistent with ongoing tectonic activity. Additionally, we identified several changes in areas adjacent to hollow formations, consistent with present-day activity. These detected changes will be critical targets for the upcoming BepiColombo mission.
The data suggests several things. First, if the changes all come from impacts, than the number of asteroids in the inner part of the solar system where Mercury orbits the Sun is much higher than believed. Since it is very hard to observe asteroids there because of the Sun, this very well might be true.
Second, if the changes were not all caused by impacts, then they occurred either from earthquakes or the environmental extremes caused by daily and seasonal changes.
Using archival data collected from 2011 to 2015 while the orbiter Messenger circled Mercury, scientists have located twenty spots on the planet where something changed during that time period. The map to the right, adapted from the paper, indicates those locations. From the paper’s abstract:
We identified at least one change likely resulting from a newly formed impact crater with bright rays that extend away from the site. If all the changes result from impact events, then the present-day rate of impactors striking the innermost planet is 1,000 times higher than models predict. Therefore, we investigate other sources for these detected changes. We located several changes on steep slopes near tectonic landforms, consistent with ongoing tectonic activity. Additionally, we identified several changes in areas adjacent to hollow formations, consistent with present-day activity. These detected changes will be critical targets for the upcoming BepiColombo mission.
The data suggests several things. First, if the changes all come from impacts, than the number of asteroids in the inner part of the solar system where Mercury orbits the Sun is much higher than believed. Since it is very hard to observe asteroids there because of the Sun, this very well might be true.
Second, if the changes were not all caused by impacts, then they occurred either from earthquakes or the environmental extremes caused by daily and seasonal changes.