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6 Greetings, Earthlings!
Greetings, Earthlings! 8 same technology scientists could use to sample Would-Bes: 6 Scientists Who Were Passed Up
those regions, Grinspoon said.
Ways Aliens Could for the Prize]
Contact Us 4. Radio waves: In a 1959 paper in the 7. Needle in a haystack: Even if aliens are
journal Nature, physicists Philip Morrison and trying to make contact, there's no guarantee we'd
Giuseppe Cocconi argued that scientists should receive their messages. The universe is 91
By Tia Ghose, Senior Writer
scour radio waves for signs of extraterrestrial billion light-years across, and messages could
LiveScience.com
life. That's because radio waves travel relatively come from anywhere.
undisturbed through the universe, not being To narrow the search, some argue that
absorbed or re-emitted by celestial objects. aliens are likelier to send messages our way if
Beyond Earth Thus, the duo reasoned, any extraterrestrials they know we're here. A study published in
hoping for their message to be relayed across February 2016 in the preprint journal
From a few subtle radio signals to alien long distances would logically resort to this arXivfound that there are 82 stars we know of in
monsters bombing the White House, science medium, said David Grinspoon, an Earth's transit zone, or an area of the sky that has
fiction is replete with depictions of aliens astrobiologist at the Planetary Science Institute. a direct line of sight to Earth.
making contact with mere mortals. For decades, that's been the predominant "Along this line, there is a very small
While some of those depictions are far- way to search for aliens. For instance, the band— a strip of less than a degree from where
fetched, it turns out that scientists have spent Search for Extraterrestrial Intelligence (SETI) extrasolar observers would see the Earth
countless hours thinking about just how has scoured telescope data for signal-like radio transiting the sun," said study co-author René
extraterrestrial civilizations could contact waves. Heller, an astrobiologist at the Max Planck
humans. Some of their ideas are nearly as Of course, the whole search rests on the Institute for Solar System Research in
fantastical as Hollywood's wildest tales. assumption that aliens are thinking just like us, Göttingen, Germany.
From alien megastructures to miniature which may not be the case. Heller and his colleague Ralph Pudritz at
robots, here are some of the more radical ways "Aliens don't necessarily read Nature McMaster University in Hamilton, Canada,
"little green men" are likely to contact humans. magazine," Grinspoon told Live Science. predicted that there may be up to 100,000 stars
within this zone of the sky — some of which
1. Mega construction: Of course, signs of 5. Radiating away: Of course, not all aliens could have planets teeming with life orbiting
intelligent life don't have to be tiny objects — will be on a mission to find other creatures in them.
they could also be really, really big ones. Some the big, lonely universe. Some may be more like One advantage of this approach is that
scientists have argued that alien megastructures hermits, hoping to hide their existence. If that's the tiny slice of the sky is relatively easy to
could be like a giant "come here" sign pointing the case, they'd make no attempts to broadcast search.
other civilizations to their presence, Grinspoon their existence. "You could just skim or scan the whole
said. In fact, scientists recently kept their eye on However, theoretical physicist Freeman Earth transit zone over the course of maybe a
the star KIC 8462852, which dimmed and Dyson has argued that even celestial hermit few dozen nights or so, depending on how large
brightened mysteriously over the past several kingdoms might develop technology to siphon the field of view of your radio telescope is,"
years. Some have argued that the star is energy from a nearby star using an orbiting Heller told Live Science.
surrounded by an alien megastructure that is object known as a Dyson sphere. If these hidden exoplanets harbor life,
occasionally blocking light from the star — "It doesn't have to be a sphere at all," they'd also be in the same galactic neighborhood
though other explanations include a swarm of Dyson previously told Live Science, "just any — just a few hundred light-years away at most.
exoplanets or a planet-forming disc. place where aliens happen to be generating a lot
In December 2015, scientists reported a of energy." 8. Part of space exploration: The search
complete lack of communication from the These Dyson spheres would then throw for intelligent life-forms may not need dedicated
region. off waste heat, an inescapable byproduct of megaprojects, Grinspoon said.
"We found no evidence of an advanced harnessing star power, in the form of infrared "We're going to send spacecraft out to
civilization beaming intentional laser signals radiation. Already, researchers at the Allen these places to explore," Grinspoon said,
toward Earth," study co-author Douglas Vakoch, Telescope Array and the Wide-field Infrared referring to spots like the asteroid belt. "So
president of METI International in San Survey Explorer(WISE) space telescope are while we explore the solar system, we should at
Francisco, said in a statement. scouring the skies for signs of such waste least be aware of the possibility of finding
radiation. something really anomalous that would be
2. Laser pulses: Repetitive laser pulses could artificial."
also be a sign of an alien race trying to get in 6. Star dance: Others have proposed that Either way, if there are smart creatures in
contact with us, because, in theory, lasers could highly advanced civilizations could be the universe, odds are, they know exactly what
send signals or messages across vast distances, advanced astro-engineers, moving stars into to do to make contact.
Grinspoon said. To find those laser pulses, bizarre or highly geometric alignments that are "Mathematically, it's pretty easy to show,
researchers have zeroed in on extremely bright unlikely to occur by chance, Grinspoon said. and logically, it makes sense that they would be
flashes of light, which are less likely to be "They could construct something that much more advanced," Grinspoon said. "We're
caused by natural phenomena. would be visible from a huge distance across the such babies as a civilization; anybody that is
So far, however, they've found no sign of galaxy, or even from another galaxy, that would outside trying to contact us probably has a much
alien signals. be obviously artificial," Grinspoon said. longer relationship with science and
technology."
"Nobody's seen anything like that."
3. Robot probes: Alien signals may not be Others might actually harness star So, if aliens are trying to contact us, it's
traveling in electromagnetic waves at all. power to create messages. For instance, if aliens probably our fault that we're missing their
Instead, signs of intelligent life may be very could spin small and extremely dense stars signals, Grinspoon said. []
small objects that advanced civilizations send called neutron stars in just the right way, they
out to explore the universe. could make these stars emit light as a kind of Whether You’re A
"Most of the solar system is still flashing beacon, Grinspoon said. SKEPTIC or BELEIVER
unexplored, so for all we know, there could be In fact, when neutron stars were Join Rob McConnell
alien probes orbiting on the asteroid belt or discovered, scientists thought they might be on
somewhere on the surface of Mars," Grinspoon messages from "little green men." (That The ‘X’ Zone Radio/TV Show on
said. "They could be quite miniature. Who discovery earned astronomer Antony Hewish www.XZBN.net
knows what alien technology is capable of — the Nobel Prize in physics; his graduate student and
they could be the size of golf balls." Jocelyn Bell Burnell, who first discovered the www.SimulTV.com
Finding these objects could rely on the star, was passed up for the high honor.) [Nobel