Searching for aliens who already know we are here

Are we alone in the universe? To answer this question, astronomers have been using a variety of methods in the past decades to search for habitable planets and for the signals from extraterrestrial observers.

The first part of this venture has been highly successful: More than 2,000 planets around distant stars — so called exoplanets — have been found so far. The second part, the search for extraterrestrial intelligence (SETI), has not yet been successful.

Maybe the search strategy has not been optimized until now, said researchers from the Max Planck Institute for Solar System Research (MPS) in Göttingen, Germany, and from McMaster University in Canada. They suggest that future searches focus on that part of the sky in which distant observers can notice the yearly transit of Earth in front of the Sun.

Observers in this zone could have discovered Earth with the same techniques that are used by terrestrial astronomers to discover and characterize exoplanets. According to the researchers, the probability that extraterrestrials are already deliberately sending us signals is much higher in this part of the sky.

This strategy reduces the region that needs to be searched to about two thousandths of the sky, drastically reducing the amount of data to be analyzed.

When a planet passes in front of its host star, it causes a small transient dimming of the star. This so called transit can be measurable, depending on the size on the planet and the sensitivity of the instrument. In fact, the majority of the exoplanets known to us today have been discovered with this transit method. A similar technique, called transit spectroscopy, might enable astronomers in the future to scan the atmospheres of exoplanets for gaseous indicators of life.

In a first step, the two researchers identified the region in the sky from which one sees the transits less than half a solar radius from the center of the solar disk. The possible exoplanetary systems that offer this perspective are all located in a small strip in the sky, the projection of Earth’s orbit around the Sun (the ecliptic) onto the celestial sphere. The area of this strip amounts only to about two thousandths of the entire sky.

“The key point of this strategy is that it confines the search area to a very small part of the sky. As a consequence, it might take us less than a human life span to find out whether or not there are extraterrestrial astronomers who have found the Earth. They may have detected Earth’s biogenic atmosphere and started to contact whoever is home,” said René Heller from MPS.

Not every star is equally well suited as a home of extraterrestrial life. The more massive a star, the shorter is its life span. Yet, a long stellar life is considered a prerequisite for the development of higher life forms. Therefore the researchers compiled a list of stars that are not only in the advantageous part of the sky, but also offer good chances of hosting evolved forms of life, that is, intelligent life. The researchers compiled a list of 82 nearby Sun-like stars that satisfy their criteria. This catalog can now serve as an immediate target list for SETI initiatives.

Sourced through Scoop.it from: www.astronomy.com

See on Scoop.itPierre Ratcliffe

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Toshiba’s Chihira Kanae robot is human-like and speaks 4 languages

Toshiba has shown off the latest generation of its Chihira robot at a trade fair in Berlin.


The machine – which is designed to look as human-like as possible – has had the German language added to its repertoire. The firm also told the BBC that it upgraded the machine’s control system to make its movements smoother. However, one expert suggested the realistic appearance might not be best suited to Western audiences.


Prof Noel Sharkey – a roboticist at the University of Sheffield – said he thought the machine still fell « clearly on this side of the uncanny valley ». The term refers to the fact that many people feel increasingly uncomfortable the closer a robot gets to appearing like a human being, so long as the two remain distinguishable.


Toshiba brought the Chihira Kanae droid to the ITB travel expo to highlight what it hopes could become a viable product for the tourism industry. The machine has been installed at an information desk where it responds to attendees’ verbal questions about the conference.


It marks the first appearance of the robot outside Japan, where it was unveiled last month.


The earlier models in the series are:

  • Chihira Aico, which made its debut at Japan’s Ceatec tech show in 2014
  • Chihira Junko, which was launched last October and is currently in use at a Tokyo shopping centre’s information desk


« We have improved the software and the hardware to improve the air pressure system, » explained Hitoshi Tokuda, chief specialist at Toshiba’s research and development center. « If the air pressure is unstable, her movements become affected by vibrations. So, if the air flow is very precisely controlled, her movements are smoother. »

Sourced through Scoop.it from: www.bbc.com

See on Scoop.itAmazing Science

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