One of the greatest advances in space observation history is the James Webb Space Telescope.
The scientific community has great hopes for this space telescope because it is significantly
more powerful than any other space telescope ever deployed by humanity.
There are billions of miles between us and the stars, but that doesn't make them any
less interesting.
While their dazzling display of light in the night sky is appreciated by many, it is the
planets that orbit them that scientists find most intriguing.
With the recent discovery of life signs on one of these planets by the cutting-edge James
Webb Space Telescope, astronomers have more incentive than ever to keep an eye on it.
What evidence did the JWST find?
On which planet did the telescope make this discovery?
In this video, we'll explain how the James Webb Space Telescope found evidence of life
on a faraway planet.
In April of 2019, a radio signal was detected that was thought to have originated in the
Proxima Centauri area.
The signal, which has since been dubbed Breakthrough Listen Candidate 1 or BLC-1, was discovered
as a consequence of the Breakthrough Listen project, which was established to seek for
intelligent extraterrestrial communication throughout the Universe.
The project has garnered nearly $100 million in financing and has dedicated thousands of
hours of telescope observation time in cutting-edge facilities around the world.
The program, which began in January 2016, is still the most extensive search for extraterrestrial
communication outside of our solar system.
The CSIRO Parkes Radio Telescope in New South Wales, Australia, detected the signal or techno
signature.
The telescope was observing the region of the nearest star to our sun, Proxima Centauri,
at the time of the discovery, as it had done hundreds of times previously.
The telescope collected large volumes of data over time, and scientists did not recognize
this signal straight away.
At the end of each observation cycle, they had to sort through hundreds of thousands,
if not millions, of signals to find any unique techno signals that could have come from space.
Moreover, the signals must have two distinct traits.
The first was that it had to be limited to a relatively small band of frequencies, much
as radio broadcast on Earth.
This is unusual since no natural mechanism can produce such a signal, and it would certainly
raise red flags if it came from space.
The second property is that the frequency of the signal must fluctuate in a manner analogous
to exoplanet motion relative to Earth.
The telescope in Australia picked up nearly 4 million individual signals during this specific
observation cycle, and the scientists had to go to work sifting out unnecessary signals
and discarding the remainder.
The team was able to filter out most of the background signals from Earth, leaving almost
5000 distinct signals.
The crew then had to cross-check these signals with contemporary radio transmitters on Earth
and were eventually left with this single unexplained signal!
This signal was characterized by the experts as a one-of-a-kind techno signature with a
narrow Broadband that appeared over a 30-hour observation period and only when the telescope
was pointing at Proxima Centauri.
The discovery of BLC-1 showed that it could have originated from Proxima Centauri and
shared characteristics with the WOW signal detected in 1977.
The WOW signal was a strong narrowband radio signal discovered by the Big Ear Radio Telescope
at Ohio State University, which was the leading technology used in the search for extraterrestrial
intelligence.
WOW appeared to have originated in the constellation Sagittarius and was the first indication of
extraterrestrial communication outside our solar system.
The signal lasted roughly 72 seconds and has not been observed by any other telescope anywhere
in the world afterward.
Several explanations about the origins of the WOW signal have been proposed, including
human-made sources, none of which have fully explained the signal's origins.
It is currently the most compelling evidence for a radio-transmitting extraterrestrial
civilization outside our solar system.
Let us now discuss Proxima Centauri and the possibility of life on Proxima B!
Proxima Centauri experiences periodic solar flares, and it is unclear whether the subsequent
ionization would remove any atmosphere that Proxima B might have.
It has been suggested that if Proxima B has a molten core like Earth and rotates on its
axis every 11.2 days, this may be enough to form a planetary magnetic field that protects
the atmosphere.
Even if there is no native life on Proxima B, this could be advantageous.
This is because many arbitrary branch points in the development of life could have resulted
in life evolving quite differently on other planets than it does on Earth.
This form of alien life would almost certainly be harmful to humans.
As a result, a sterile Planet may be preferable to a biologically hostile one as a colony
site.
Pre-sterilization like this could make it easier to relocate a simplified version of
Earth's ecology to Proxima B.
But what about Proxima B's gravity?
This exoplanet, like the Earth, has gravity!
Proxima is at least 1.3 times the size of Earth and might be substantially larger assuming
Proxima B is spherical with a mass of 1.5 Earth masses and roughly the same mass density.
The surface gravity of Proxima B would be around 1.145 G, or 11.22 meters per second
squared.
As a result, you push the scale 14% higher than on Earth.
However, there is another element that can dramatically alter our calculation.
The Earth has a comparatively high density due to its iron nickel core, but Proxima B,
like Mars, may not have such a core.
So, assuming Proxima B had the same mass density as Mars, or 3.93 grams per cubic centimeter,
the surface gravity on Proxima B would be 0.866 g's, or 8.5 meters per second squared,
and you would weigh 14 less than on Earth.
However, Proxima B may not be spherical because enormous tidal pressures would shape the tide-locked
planet into an ovoid or egg with a long axis pointing at the star.
As a result, any habitable zone would be placed in the ovoid's mid area, where its radius
is the shortest, implying that the habitable mid region would be closer to the planet's
center.
Surface gravity would be greater here than in the hot and cold zones.
If the radius was reduced by ten percent, gravity would be increased by twenty percent.
In addition to investigating the likelihood of life on Proxima B, scientists have attempted
to establish what the Earth would look like as a planet if it orbited Proxima Centauri.
They used modelling to predict how the situation would unfold.
Proxima B's orbit is in the habitable zone, which is the distance from its host star where
water may pool on the planet's surface, but that doesn't imply it's livable.
It doesn't factor in things like whether or not there's water on the planet or if an atmosphere
could survive in that orbit.
Atmospheres are also necessary for life as we know it because they enable climate management,
the maintenance of water-friendly surface pressure, protection from harmful space weather,
and the storage of life's chemical building components.
The magnetic field and gravity of Earth's atmosphere were employed as approximations
for Proxima B in the scientist's computer model.
They also computed how much radiation Proxima Centauri emits on average using data from
NASA's Chandra x-ray Observatory.
Using this data, their model predicts how the exoplanet's atmosphere is affected by
the host star's powerful radiation and periodic flares.
When high energy severe ultraviolet radiation ionizes atmospheric molecules, knocking off
electrons and producing a swath of electrically charged particles, an active Red Dwarf star
like Proxima Centauri takes away the atmosphere.
The freshly generated electrons gain enough energy during this process to easily escape
the planet's gravity and dash out of the atmosphere.
As more negatively charged electrons leave the atmosphere, they create a tremendous charge
separation that pulls positively charged ions out into space with them.
Proxima B experiences bursts of severe ultraviolet radiation hundreds of times stronger than
Earth does from the Sun in Proxima Centauri's habitable zone.
Their radiation generates enough energy to tear away not only the lightest molecules
of hydrogen, but also heavier elements like oxygen and nitrogen over time.
According to the model, Proxima Centauri's intense radiation drains the Earth-like atmosphere
up to 10,000 times faster than what happens on Earth.
Alpha Centauri is tidally bound to Proxima B!
What does this mean, and what are the implications?
You're probably aware that the Sun and Moon exert tidal forces on the oceans of the Earth.
This form of force is determined by the mass density of the producing object as well as
the power of the angular size of the third object in the sky.
Even though the Sun and moon appear to be roughly the same angular size to an observer
on Earth, the moon's tidal influence is three times that of the Sun because the moon has
three times the Sun's mass density.
Because Proxima B has such a short orbital radius, the star Proxima Centauri seems to
have a 2.86 times bigger angular diameter in the sky than our own Sun as viewed from
Earth.
Because Proxima Centauri has 40 times the density of the sun, the tidal force exerted
by Proxima Centauri on Proxima B will be 939 times more than that exerted by the sun on
Earth.
As a result, Proxima B is most likely still locked to Proxima Centauri.
This means that Proxima B, like Earth's Moon, will constantly offer the same face to Proxima
Centauri.
Therefore, Proxima B will have a deep-frozen cold side and a scorching side reminiscent
of a desert.
However, there will be a Twilight Zone band around its mid-region where this star will
constantly be just above or below the Horizon.
The temperature in this location will not be exceptionally hot or freezing.
So, how will the JWST seek for life on Proxima B?
Extraterrestrial plant life may be the first to show indicators of life outside our solar
system.
For example, while on its way to Jupiter, the Galileo spacecraft aimed its instruments
back to Earth and detected clear traces of plant life.
It discovered the vegetation red Edge, or VRE biosignature.
Plants emit a combination of red and infrared light.
Similarly, the JWST will measure Proxima B's VRE.
If there is a jungle on Proxima B, for example, it will produce a big VRE signal that should
be easy to detect.
Apart from plant life, the JWST can search for indications of life in Proxima B's atmosphere.
When an exoplanet passes in front of its star, sunlight passes through its atmosphere and
is captured by the JWST.
The JWST would next utilize spectroscopy to determine which wavelengths are absent from
the light because atoms and molecules in the atmosphere absorb specific wavelengths, leaving
a unique fingerprint for the JWST to detect.
The makeup of Proxima B's atmosphere may thus be calculated, and the presence of Life may
be established.
Let us know what you think about the discovery of life outside the solar system in the comments
below.