Are we really alone?
On a clear night, you can see a faint white milky streak across the sky. This spiral galaxy is known as the Milky Way. Our solar system is located in the outer reaches of the Milky Way.
There are about 200-400 billion stars, many of them like the Sun in the Milky Way. Almost every star in the Milky Way is home to at least one planet. In other words, there are at least 200 billion planets in the Milky Way.
Scientists involved in the Search for Extra-Terrestrial Intelligence (SETI), scan the sky with radio telescopes to detect radio signals emanating from outer space. They apply the Drake Equation which was formulated by astronomer Frank Drake in 1961 to calculate the likelihood of making radio contact with extra-terrestrials. According to the latter, there could possibly be about 10,000 radio-transmitting civilisations in the Milky Way. In 2009, astrophysicist Duncan Forgan had estimated that at least 361 and possibly up to 37, 964 planets in the Milky Way could be harbouring life.
Come to think of it, the Milky Way is just one of the 100 billion galaxies in the Universe, each containing at least 100 billion stars.
Are we really alone in the Universe? It is a question that has vexed man for ages. A poll conducted by a TV channel in the UK in 2012 has revealed that this question still tops the list of mysteries that people are most desperate to see solved.