Scientists believe that UFOs scare is due to misidentified conventional objects or natural phenomena like night-flying aircraft, balloons, noctilucent clouds, nacreous clouds, or astronomical objects such as meteors or bright planets causing optical illusions. Many purported UFO sightings are even planned hoaxes to create sensations.
However, some scientists are open to idea and call for continued scientific study and favour the observance of day to remain alert about invasion of the earth's sky by aliens and UFOs. Moreover, UFOs have become a relevant theme in modern culture popular with many teenagers and some adults. The reports about UFO sightings continue subject of scientific research as well as academic research in sociology and psychology.
Many scientists believe that extraterrestrial life exists but there is no direct evidence of its existence so far. For the last seven decades, there has been an ongoing search for signs of extraterrestrial life by analysing radio signals coming from outer space to detect possible extraterrestrial intelligent signals. Space telescopes are being used to search for potentially habitable extra-solar earth-like planets. However, no evidence is in sight to conclusively prove the existence of aliens yet.