Why certainly? It is not as if we have not been trying. The search for extraterrestrial intelligence (SETI) has been going on for over half a century. It has largely drawn a blank. But when in a when there is a flurry of excitement. Here are some of the highlights.
Study far more: "Is the answer to life, the universe and anything 37?"
On eight April 1960, Cornell University astronomer Frank Drake pointed a 26-metre radio telescope at two nearby stars. The telescope - primarily based at the US National Radio Astronomy Observatory (NRAO) in West Virginia - was tuned to a frequency of 1420 megahertz, the wavelength of radiation naturally emitted by hydrogen in space. Therefore began Project Ozma, the first experiment explicitly developed to appear for aliens.
Drake was hoping to detect radio waves sent by an extraterrestrial civilisation. He chose the emission frequency of hydrogen since it is the most abundant element in the universe, and therefore an clear signal for any intelligent civilisation trying to get itself noticed by one more.
Even though the stars - Tau Ceti and Epsilon Eridani - were viewed as promising candidates, being nearby and sun-like, Project Ozma detected absolutely nothing in over 150 hours of observation.
In 1972, astronomers at NRAO had a second go, this time utilizing a larger telescope that collected as considerably data in a minute as the older one particular could in 19 years. They sporadically monitored far more than 650 stars for four years, again browsing for the hydrogen signal - and once again getting absolutely nothing. But the Ozma projects established SETI as a credible discipline and set the scene for a lot of extra attempts.
1 of the projects inspired by Ozma was the "Large Ear" programme at Ohio State University, which ran from 1973 to 1995. On 15 August 1977, its 79-metre dish picked up a potent burst of radio waves from the basic path of Sagittarius.
The burst lasted 72 seconds and was very close to the emission frequency of hydrogen - deemed a likely candidate for alien messages. When astronomer Jerry Ehman saw the signal recorded on a personal computer printout, he circled it in red pen and scrawled "Wow!" on the sheet of paper.
The set-up of the telescope produced it hard to operate out specifically exactly where the burst came from, but the common patch of sky was identified.
The "Wow!" signal remains the most promising putative alien signal ever detected by SETI. But in spite of in depth searches of the identical patch of sky it has in no way been noticed given that.
In 2007, astronomers at West Virginia University found a previously unknown celestial phenomenon: a super-intense, extremely brief burst of radio waves apparently originating outside our galaxy.
The Speedy Radio Burst lasted for just 15 milliseconds but released far more power than the sun emits in about a month. Calculations recommended that it came from an object no additional than 1500 kilometres across.
At the time there was no clear explanation for the FRB. Astronomers speculated that it came from a single cataclysmic occasion, such as the final collapse of a dying black hole or the merger of two neutron stars.
A handful of other FRBs have due to the fact been detected but there is still no agreed explanation.
Inevitably, the gap has been filled by speculation that FRBs are messages from aliens. Earlier this year, Nigel Watson, author of the
UFO Investigations Manual, told the UK's Daily Mail newspaper that FRBs could be evidence of a "vast alien communication network". Or, he said, it could just be an as-but-unknown astronomical phenomenon.
In the absence of a smoking gun from the sky, some alien hunters have looked for indicators on our doorstep. For a even though, crop circles - strange geometric patterns that started to appear in arable fields in southern England in the 1970s - had been claimed by several persons to be messages from ET. They are now known to be the work of artists and pranksters.
Around a decade ago a slightly additional serious concept started to circulate: maybe there are alien messages in our DNA. As Paul Davies, author of The Eerie Silence: Renewing our search for alien intelligence, wrote in New Scientist in 2004: "May ET have inserted a message into the genomes of terrestrial organisms, perhaps by delivering very carefully crafted viruses in tiny space probes to infect host cells with message-laden DNA?"
A decade on, we have no evidence whatsoever that ET did this. In the past couple of years the thought has been revived in a slightly unique kind: a pair of Kazakh researchers have proposed that the genetic code would be a much better location to plant a signal, and even claim to have discovered what they call "the Wow! signal of the genetic code" (see "Is the answer to life, the universe and every little thing 37?"). - MACRO INSIDER.
