'You could be the one to discover ET', says amateur astronomer
Any amateur astronomer could be the first to discover aliens, according to a Dublin man with a record for space discovery.
David Grennan, from Raheny, was the first Irish person to discover a supernova - and he did it using his own homemade equipment.
David gave a lecture at Trinity College with the theme, "There's nothing amateur about science" to encourage those with no background in the subject to get involved.
"Astronomy in general is one of the only sciences where professionals and amateurs can collaborate on equal footing," he said.
"If you were to collaborate in pharmacology, the only thing to come out of it would be a meeting with the police."
He discovered his first supernova in 2010, and his second, named 212ej by the International Astronomical Union (IAU), in 2012.
His last supernova discovery was confirmed as a rare event by a team of professional astronomers in China, and designated a special status by the IAU in 2014.
The explosion occurred in a galaxy more than 170 quadrillion miles away.
In 2006 he built a "significant" observatory with a friend, Dave McDonald.
Between 2008 and 2009 the pair discovered four new asteroids and were the first Irish discoverers of an asteroid since 1848.
"It was the first time we were putting our foot into the fire so to speak," he said.
David has no formal education in physics.
"When I was in school, the class was asked to put up their hands for either biology or physics and only me and another lad put ours up for physics - so we had to do biology," he said.
David said amateurs can use software on their computers to scan the skies "while you're watching Netflix".
One program, Einstein@Home, can help budding astronomers get a start.
It uses a computer's idle time to search for weak astrophysical signals from spinning neutron stars or pulsars, using data from a range of official sources.
Einstein@Home volunteers have discovered around 50 new neutron stars.