For what reason, NASA sends a new signal to aliens?
Source: (
https://bit.ly/3NniOpP)
Should we transmit another message to possible extraterrestrial
intelligences in the Milky Way galaxy? Yes, say a team of scientists
led by NASAs Jet Propulsion Laboratory in Los Angeles, who
have developed a binary-coded message that contains images of
humans, our cosmic address and a request to RSVP.
If its transmitted, this so-called Beacon in the Galaxy will
follow a tradition begun in 1974 when scientists sent a message
containing basic information about us and our planet into space
using the now-defunct Arecibo radio telescope.
Its an update to the famed Arecibo message, which was designed
by Frank Drake, an American astronomer whose famous Drake
Equation seeks to estimate the number of active, communicative
extraterrestrial civilizations in our Milky Way galaxy.
Although the Arecibo message described humanity and our place
in space in simple graphic terms, it was more a demonstration of
human technological achievement. So too the Beacon in the
Galaxy, which will also be coded in binary. The concept, published
as a pre-print, has been submitted to the Journal of Galaxies.
Not much so far ... since its target is M13, a globular cluster of
ancient stars, is 25,000 light-years distant, and radio signals travel
at the speed of light, the messagesent at wavelength 126 millimeters
is only 48 years into its long journey. The electromagnetic waves
conveying the Arecibo Message have traversed less than 0.2% of
the distance to their intended target, reads the paper.
The Beacon in the Galaxy is an effort to use basic mathematical
and physical concepts to establish a universal means of communication
that could be decoded and interpreted by intelligences not of this
Earth.
Cue binary coding (the simplest form of mathematics and likely
universal across all intelligence), and a message that focuses almost
entirely on mathematics and physics rather than possibly confusing
human culture and language. Its also carefully-crafted to illicit the
kind of reply that humans would want from an extraterrestrial
intelligence; its an invitation for a cosmic conversation that could
span many centuries.
What is in the Beacon in the Galaxy?
- information on the biochemical composition of life on Earth
(including a visual depiction of the four constituent bases of DNA:
adenosine, cytidine, guanosine, and thymidine).
- a timeline originating from the Big Bang to indicate the universal
time the signal was sent (and also scientific dates of events that
advanced humanity, such as Isaac Newton discovering his Laws
of motion and force, Einsteins Relativity, the start of the Space
Age and the Moon landing in 1969).
- the Solar System's time-stamped position in the Milky Way
relative to known globular clusters (so aliens know where to beam
their reply and when to expect their message to arrive).
- digitized depictions of the Solar System and Earths surface.
- digitized images of humans.
- an invitation for any receiving intelligences to respond (an image
of the transmitting telescope and another generic telescope sending
transmissions to each other).
Since the first faint flickering of sentience dawned in the primal
minds of modern humans distant ancestors some hundred thousand
generations ago, we have sought to communicate, reads the paper.
It goes on to say that ancient scholars gazed at the stars and asked
the most profound of all questions: are we alone? It would take
five millennium to progress from Sumerian cuneiform to the great
radio telescopes of the 20th and 21st centuries and with that,
the means to finally begin seeking out an answer, it reads.
The beamed radio wave coded in binary will be sent using one of
the two biggest and most powerful radio telescopes on Earth the
familiar dish-shaped Five-hundred-meter Aperture Spherical radio
Telescope (FAST, but also called Tianyan) in Guizhou, southwest
China and the 42 antennas of the SETI Institute's Allen Telescope
Array (ATA) in Hat Creek, northern California.
FAST is the successor to the collapsed Arecibo radio telescope,
but it has is overall performance and sensitivity are several times
higher.
There is one small problemboth FAST and the ATA can only
receive radio messages, not send thembut upcoming upgrades
may fix this.
The authors suggest aiming for the area of the Milky Way most
likely to contain intelligent life, reckoning that to be a star
cluster between two and six kiloparsecs (kph) from the center
of the galaxy.
A kiloparsec is equivalent to 3,260 light years, so were talking
about star cluster roughly 6,000 to 20,000 light-years distant.
Thats a lot closer than the target of the Arecibo Message
though
not exactly close. We maximize the chances of the message being
received by an ETI, reads the paper. Thus, we maximize the
probability of receiving a response in the distant future.
Its no accident that the appearance of the Beacon in the Galaxy
comes just before the 50th anniversary of the Arecibo Message,
but the actual timing is crucial if its to reach the intended
destination.
For the message to travel to its target with maximum contrast,
the least radio interference and to reduce absorption by the Earths
atmosphere it would need to be sent when the separation angle
between the Earth and the Sun is as large as possible. That means
around March 30 or October 4 in any given year.
What is the Beacon in the Galaxy actually for? This messages
ultimate goal is to start a dialogue
no matter how far in the
future that might occur, reads the paper. Humanity has a
compelling story to share and the desire to know of others and
now the means to do so.