Page 25 - The 'X' Chronicles Newspaper - September 2021

ET May Already Be Watching Us 25

Aliens Might Already Be
Watching Us

A new star map reveals more
than 2,000 stars, some with their
own planets, that have a direct

view of our planetary presence

By Tess Joosse

On June 25 the Pentagon and the Office of the
Director of National Intelligence released their
much hyped report on unidentified aerial
phenomena, or UAP. Space alien enthusiasts and
skeptics alike awaited it with bated breath. And
while the report did not rule out an
extraterrestrial origin for much of the
documented UAP, it was short on details or
bombshells.

But we already know our world is easily
detectable by extrasolar observers. A paper
So the pair settled on a 10,000-year window of his colleagues created a similar map in 2016,
published on June 23 in Nature shows that in the
stretching from 5,000 years ago to 5,000 years although that earlier work tallied just 82 stars
past 5,000 years, 1,715 stars have been in the
from now. The time line is conservative, Faherty that would be aligned in the right position—and
right celestial position to view a populated Earth
says, considering Earth is 4.55 billion years old. it did not implement the temporal component
transiting the sun—with 319 more entering this
But the temporal component is still especially that the Gaia data set allowed Kaltenegger and
sweet spot in the next 5,000 years. And seven of
significant because everything in space is Faherty to include in their new paper. “We
these far-off stars are known to have their own
moving over time, says René Heller, an thought about whether others might look for
orbiting exoplanets that might support life.
astrophysicist at the Max Planck Institute for transiting planets as we do but from an
Solar Systems Research in Göttingen, Germany, extrasolar perspective,” Heller says of his
“Instead of constantly saying, ‘What can we
who was not involved with the study. “What’s previous work. “And some of them might be
detect from other worlds?’ and ‘Where are the
happening in space is dynamic—it’s not a static lucky in seeing us earthlings transiting in front
other worlds that we can detect?’ think about it
picture!” he says. of the sun.”
the other way,” says Jackie Faherty, an
astronomer at the American Museum of Natural
From the Gaia data set, Faherty and Kaltenegger Looking at Earth and the solar system from this
History in New York City and a co-author of the
picked out the stars within about 300 light-years flipped perspective is extremely valuable,
new study. “What worlds can find us? How
of our sun—those “in our neighborhood,” Kaltenegger says. “The most impressive image
many of them and for how long?”
Faherty says. Thanks to Gaia and other surveys, ever, I think, is the pale blue dot picture that Carl
the researchers already knew how fast each star Sagan helped to make.” In that famous
Lisa Kaltenegger, an astronomer at Cornell
is moving, so they pushed the stars’ trajectories photograph, captured by the outbound Voyager 1
University, approached Faherty with the idea to
backward and forward through time on a big probe beyond the orbit of Pluto, a minuscule
create a map showing which nearby stars could
virtual map. This approach allowed them to pinprick of light (Earth) hangs in a diagonal
see Earth in the past and future. “I wanted to do
determine when and where these neighborhood sunbeam against the dark void of space, its
a billion years!” Kaltenegger says of the
stars entered, or will enter, the so-called Earth vaguely cyan color hinting at the presence of
proposed time line. “And I was like, ‘No, there’s
transit zone, or what Faherty calls the “bull’s eye watery oceans and clouds. The image is a
a finite clock backtrack you can do,’” Faherty
in the sky”: the area where a star may be aligned viscerally visual depiction of William Blake’s
explains.
just right to get a glimpse of our world crossing oft-quoted musing about glimpsing “a world in a
the face of the sun. grain of sand,” showing how even a single pixel
The data set the two researchers used came from
of planetary light falling on some faraway
the Gaia mission, a spacecraft launched by the
That is the same method astronomers here on detector can reveal surprising amounts of
European Space Agency in 2013 to tally and
Earth have used with great success to find and astrobiologically relevant information. The view
track more than a billion stars throughout the
study thousands of worlds around other stars. By from Voyager 1 is a testament to the chilling,
Milky Way. It uses a distance-measuring
monitoring a star continuously, observers can exhilarating fact that, just as we can see
technique called parallax, which can be
seek out a regular pattern of “dimmings and ourselves from the interstellar depths, others
understood by simply winking one eye, then the
rebrightenings” produced by shadowy planets can, too.
other and noticing how objects in your field of
parading across the star’s face as seen from our
view shift in proportion to their proximity to
solar system. This remarkable method does not (Continued on Page 27)
you. “Your eyes are separated by a small amount
just tell us if there are planets encircling a star—
of a distance, and that distance between your
it also allows observers to scry the bulk More FACT*oids…
eyes is what allows you to measure depth,”
chemical composition of the planet’s air via
Faherty explains. That is what Gaia does, too,
starlight shining through its upper atmosphere. More veggies are grown for cows than for
except its baseline is roughly the span of Earth’s
“When the planet passes in front of the star, it people.
orbit around the sun rather than the space
leaves a spectral fingerprint, as we call it—
between a person’s eyes. This longer baseline
information about its atmosphere in the The first Civil War battle reenactments were held
allows the spacecraft to more precisely measure
starlight,” Heller says. before the Civil War was even over.
celestial distances and motions. But just as with
your eyeballs, there is still some uncertainty in One day after Texas radio station KLUE banned
Kaltenegger and Faherty’s study is not, it turns
establishing the exact kinetics of these Beatles records in 1966, it was nit by lightning.
out, the first to look for other planetary systems
uberdistant objects, Faherty says.
that could catch Earth in transit. Heller and one