Milky way is home to 100 billion planets, attached to various suns or stars, and a couple of billion are similar to our own sun. In all probability, some of these planets may be home to civilizations more advanced than we are. As we know microbial life emerged on earth after it cooled down, and most star systems are billions of years older than our sun, and therefore life there could have emerged much before the emergence of single cell organisms formed here on earth.

There is research on extra-terrestrial life. It is possible that aliens or the hardware they have built might have visited the earth. There are astronomical oddities, reported sightings of UFOs or unidentified flying objects, now called UAP or unidentified anomalous phenomena. Even believers of God believe that there is extra-terrestrial life.

In October 2017, a telescope in Mauti detected something that has entered the solar system. Astronomers called it Oumuamua, meaning scout messenger. It was the first interstellar object that has been recorded. It seemed to cover a vast distance from another star system to enter our solar system. It was mysterious what its origin was. Its contours did not fit in other known astronomical categories. It could have been a rock, or an asteroid. As a rock, it was strange. Its length equalled the length of a football field. The shape was difficult to conceive — it looked like a long thin cigar. The more it was studied, the more its weird nature appeared and that struck the astronomers.

While travelling it approached the sun and then speeded up. Its acceleration could not be explained by the sun’s gravity alone. Maybe, it was a comet to have that extra acceleration. Comets being rocky snowballs, in proximity of the sun, the ice within them gets converted into water vapour. Gases are released to give them a speed boost, In addition, comets have a signature tail. In case of Oumuamua, no telescope observed its tail.

Avi Loeb, a theoretical astrophysicist at Harvard University, followed this news. He surmised that its acceleration could be attributed to sunlight. He compared its journey to a light sail, similar to wind sail of a boat. If Loeb is right, it means the object is not a natural phenonmeon, but an extra-terrestrial artifact.

Loeb is open to unconventional ideas. He published his Oumuamua hypothesis. He was saying as if an alien ship had arrived. Soon journalists made to his residence. Loeb is not alone in hypothesizing that universe could be filled with life. Astronomers too believe in this hypothesis. However, Loeb departs from them in thinking that aliens on other planets could have already made their way to us. He is outspoken about extra-terrestrial life.

In 2021, he wrote a book about Oumuamua called Extraterrestrial. It had become the best seller. His new book Intersteller will soon appear in the market.

Astronomers feel that Loeb should concentrate on new discoveries being made by James Web Space Telescope. Some feel he is not following scientific method. His disposition is speculative.