British astronomer Lady Jocelyn Bell Burnell was the first person to discover a pulsar in 1967 when she spotted a radio pulsar.
Since then, other types of pulsars emitting X-rays and gamma rays have also been identified.
Pulsars are basically rotating, highly magnetized neutron stars, but when they were discovered, it was thought that they could come from strangers.
& # 39; & # 39 Sensational!; radio signal
In 1977, an astronomer looking for an extraterrestrial life in the near-above-Ohio sky spotted a powerful radio signal so powerful that he wrote enthusiastically "Wow! next to his data.
In 1977, an astronomer looking for an extraterrestrial life in the near-above-Ohio sky spotted a powerful radio signal so powerful that he wrote enthusiastically "Wow! next to his data
The 72-second explosion, spotted by Dr. Jerry Ehman via a radio telescope, came from Sagittarius but did not correspond to any known celestial object.
Conspiracy theorists have since claimed that the "Wow! signal, 30 times more powerful than background radiation, was a message of intelligent extraterrestrials.
Fossilized Martian Microbes
In 1996, NASA and the White House announced explosively that the rock contained traces of martian bugs.
The meteorite, cataloged Allen Hills (ALH) 84001, was crushed on frozen waste from Antarctica 13,000 years ago and was recovered in 1984.
Photographs were published showing elongated segmented objects that seemed extremely realistic.
Photographs were published showing elongated segmented objects that looked extremely realistic (pictured).
However, the excitation did not last long. Other scientists have asked if the meteorite samples were contaminated.
They also argued that the heat generated during the blasting of the rock in the space could have created mineral structures that could be confused with microfossils.
Behavior of Tabby's Star in 2005
The star, also known as KIC 8462852, is 1,400 light-years away and has left perplexing astonomers since its discovery in 2015.
It darkens much faster than other stars, which some experts have suggested as being a sign of extraterrestrials exploiting the energy of a star.
The star, also known as KIC 8462852, is located 1,400 light-years away and has puzzled the astonomists since its discovery in 2015 (artist impression)
Recent studies have "eliminated the possibility of an extraterrestrial megastructure" and instead suggest that a ring of dust might be causing strange signals.
Exoplanets in the Goldilocks area in 2015
In February of this year, astronomers announced that they had spotted a star system with planets capable of supporting life just 39 light-years away.
Seven Earth-like planets have been discovered in orbit around the dwarf star 'Trappist-1'. nearby and all could have water on their surface, one of the key elements of life.
Three of the planets have such good conditions that scientists say that life may have already evolved on them.
The researchers say they will know if there is life in the planets in 10 years and they said, "This is just the beginning."