MadSci Network: Astronomy |
The Apollo astronauts left some seismometers and a highly reflective mirror on the moon. The seismometers are similar to the ones used on Earth and they detect moonquakes. The mirror is used by the McDonald Observatory in Texas to detect the exact distance of the moon from the Earth. To the best of my knowledge, both are still operational and used by scientists to collect data on the moon. This may seem amazing considering that they have been sitting unattended for around 30 years, but the moon changes very little. There are occasional moonquakes and meteor strikes, but other than that the moon is the same as when we visited around 25 years ago. One piece of information that we have gained through this equipment is that the moon is moving away from the Earth. By using a high powered laser and bouncing it off the mirror, the astronomers at McDonald's Observatory can gain very precise distances of the moon. It is moving away from the Earth at about an inch a year. In the long term (very long term), this could greatly alter the seasonal changes on the Earth, vary the climate of the Earth, and essentially do away with total solar eclipses.
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