The sighting of earth like planets is in the news much more frequently than the past. The most recent is the announcement of a discovery of a planet the size of our own Earth, raising the possibility of finding life there.
You may be wondering, “Where have these planets been hiding all these years?” You would be justified in asking this question since past discoveries of the “tenth planet” have all been explained as dwarf planets and even led the demotion of Pluto to a dwarf-planet status. Hence instead of having more planets in our solar system we now have only eight.
So where are these earth-like planets? They are in other solar systems around distant stars. The stars that we see in the night skies are actually distant suns, and the planets that orbit them are called “exoplanets” Recent technological advances have allowed us to know more about these exoplanets.
The most recent advance is the Kepler space telescope that orbits high above our Earth’s atmosphere. It is specially designed to detect planets around distant stars by measuring minute decreases in light when a planet orbiting a distant star comes between the star and the spacecraft. This is amazingly sensitive; like being able to recognize an insect crawling across the headlight of a car that is ten kilometers away from you!
More than 700 such exoplanets have been discovered so far, but most of them are giant planets like our Jupiter. Others are either too far from their parent star, and so too cold, or too near to the star, hence too hot, for any possibility of life to exist. However, the “Kepler 20f” planet is the size of Earth and at just the right distance from its star which is almost the size of our Sun. Hence it has excited scientist with expectations of finding life outside our own Earth.
The unusual rains that we have been experiencing over the past few weeks have interrupted our views of the heavens this month. Horizon clouds ruined our lunar eclipse viewing and now the whole sky is often covered with thick clouds. However skies do open up once in a while to reveal the stars beyond.
In our skies that two planets that have been shining their spotlights in the evening skies are Venus in the west and Jupiter in the east. They continue to catch the eye and you are most likely to see them in the gaps in the clouds.
DECEMBER NIGHT SKIES OVERTANZANIA
By Dr. N. T. Jiwaji (email@example.com)