Chosen for you: the most important news of these days
Hi guys, welcome to the “Space and Astronomy” news review,
selected for you by Insane Curiosity Channel! The newsletter, which will be biweekly,
will try to provide a quick overview of everything interesting that has
happened in the last few days in the field of astronomical research and space exploration.
And if you enjoyed it, let us know!
Unearthing 7 Hypothetical Dyson Spheres?
It seems that at least seven stars in the Milky Way are emitting infrared radiation that could
be compatible with the presence of hypothetical alien megastructures, the so-called Dyson Spheres,
whose existence was theorized back in the 1960s. Hinting at this possibility – still to be proven,
as there have been no clues of actual extraterrestrial intelligence found so
far – is a study published in the journal Monthly Notices of the Royal Astronomical Society by a
research group involving scientists from Sweden, India, the United Kingdom, and the United States,
in the quest for possible traces of alien technology rather than hypothetical signals
or messages that extraterrestrials might send to humanity. An example of this is the Dyson Spheres,
gigantic structures that aliens could build around stars to harness their energy.
Their existence was theorized by British physicist Freeman Dyson in an article published in Science
in 1960 and has subsequently been revisited in many science fiction stories. According to
scholars, if Dyson Spheres indeed existed, we should be able to recognize them by the large
amount of infrared radiation they emit due to their overheating. By absorbing
a vast amount of energy from the parent star, they should heat up and emit excess
heat in the form of infrared radiation. Freeman Dyson proposed these structures,
reasoning that the technological advancement of a civilization occurs at the cost of
an ever-increasing energy requirement, to the extent that, to sustain itself,
an advanced civilization needs to harness all the energy from its parent star.
Building on this premise, researchers searched for signals from hypothetical
Dyson Spheres among a sample of objects consisting of 320,000 stars. Through a
series of data analysis steps, which include the use of artificial intelligence algorithms,
researchers found 7 red dwarfs, stars with masses around 10% of that of the Sun,
whose emission of infrared light appears higher than what would be expected from such objects.
Researchers acknowledge that the infrared emissions from these 7 stars could also
have other explanations unrelated to aliens, and for this reason, they hope that further
observations can be conducted using more powerful tools, such as the James Webb Space Telescope.
Five incredible visions of the universe given to us by the Euclid Space Telescope!
More than 1,500 billion homeless stars wandering aimlessly, 29 ancient galaxies providing insights
into the universe's first billions of years, and clouds of gas and dust with captivating colors – a
total of 11 million objects revealed in visible light and another 5 million in infrared: this is
the rich bounty of the first year of life of the European Space Agency's Euclid space telescope,
the 'detective' of the dark universe launched in July 2023,
now celebrating its first year of activity with five unprecedented cosmic portraits.
The images and associated scientific results are extraordinarily diverse in
terms of objects and observed distances, yet they represent only 24 hours of observations.
Consider that the Hubble Space Telescope would have taken 6 months to cover the same field!
The images obtained are at least four times sharper than those achievable with ground-based
telescopes, akin to those acquired by Hubble, but with a capture area 175 times larger!
Two of the images released last May 23, for example, depict the large galaxy clusters
Abell 2390 and Abell 2764, which are among the most massive structures in the universe.
Clusters like these constitute large reservoirs of dark matter, making them ideal astrophysical
laboratories for studying the properties of this so far elusive component of the universe's mass.
In particular, Abell 2764, located 3.5 billion light-years away, is a very dense
cluster containing hundreds of galaxies immersed in a halo of dark matter. Euclid has captured a
wide range of objects in this corner of the sky, such as small background galaxies with
very faint light and a very bright star near the cluster: Beta Phoenicis. This demonstrates
how the telescope can "bring together" objects of very different brightness in a single view,
without being blinded by the brightest sources. Another image shows NGC 6744, which with a
diameter of 250,000 light-years (more than twice that of the Milky Way) is undoubtedly one of the
largest spiral galaxies in the local universe. It is located 31 million light-years away... and
Euclid's wide field of view (about 30 arcminutes, practically equal to the angular diameter of our
Moon, just to give you an idea) covers the entire galaxy, capturing not only the spiral structure
but also fine details, such as feather-like dust filaments emerging from the spiral arms.
Also magnificent is the capture of the two elliptical galaxies in the constellation Dorado,
where Euclid captures the ongoing gravitational interactions, visible as filamentous tidal tails.
In conclusion, we can think of Euclid as a "detective of the dark Universe" with a mission,
if not impossible, at least extremely challenging: to investigate how dark
matter and dark energy have acted to create the galaxy clusters that we see. We know that 95% of
the Universe is made up of these mysterious entities whose presence, however, subtly
alters the appearance and motion of celestial objects, making them difficult to understand.
In its operational life of six years, it will map about 15,000 square degrees of extragalactic sky,
equivalent to 36% of the entire celestial sphere, observing 12 billion galaxies!
Revealed: The Mystery of Enceladus' "Tiger Stripes," One of Saturn's Moons
Despite its small size (only 500 km in diameter), Enceladus is one of the most studied objects in
the Solar System. Beneath a thick layer of ice several kilometers thick lies a vast ocean,
with hydrothermal vents warming its waters and releasing many nutrients – conditions
that could hypothetically support life forms. But what has intrigued
planetary scientists the most are the long fractures that mark the moon's surface,
periodically spewing geysers of vapor, along with alternating light and dark stripes,
vaguely reminiscent of tiger stripes, the origin of which was still poorly understood.
According to a new study, the stripes are shaped by the tides of the hidden ocean,
timed by Enceladus's orbital period around Saturn, which is about 33 hours.
The planet's gravitational force, just 238,000 km away, moves the water masses,
cyclically causing the fractures to reopen. Vapor jets escape from these fractures each time,
depositing and coloring the surface. The evidence of the long-term influence of tides
on Enceladus's evolution also implies that the moon's subsurface ocean must be very ancient,
raising hopes for potential life evolution within it. Who knows if one day we'll be able
to set foot there, or at least send down a rover capable of giving us all the answers we need!
The Starlink Satellite Constellation Nears 6,000
In recent days, the Starlink satellite constellation for internet connections
has reached nearly 6,000 satellites. With the latest launch from Cape Canaveral, SpaceX,
led by Elon Musk, is thus approaching the symbolic figure of 6,000 satellites
placed in orbit – a record number destined to grow even further, perhaps even doubling.
Several specialized sites have been keeping count, albeit unofficially. So far, apparently
since 2019, 6,416 satellites have been launched, of which 5,999 are still in orbit... 5,923 are
actually operational. A number – as mentioned – that is still expected to grow, although there
are no official indications of what the maximum limit should be. The only certainty is that the
US Federal Communications Commission has so far authorized SpaceX to launch 12,000 satellites.
The latest launch took place during the violent geomagnetic storm due to intense solar activity,
producing polar auroras visible even from Italy, but it seems to have caused no major disturbances
either to the launch or to the satellites already in orbit. Meanwhile, SpaceX has
announced that preparations are also underway for a new test launch for Starship, the largest rocket
in history, intended to support human return missions to the Moon and then to Mars. We'll
have to wait for the authorizations, but the next launch could be scheduled for early June.
Meanwhile... apparently, a large fragment of a SpaceX rocket crashed in a Canadian farm
field... The fragment, 2 meters wide and weighing 40 kilograms, landed in Barry Sawchuk's farm in
the province of Saskatchewan, northeast of the city of Regina. The discovery was made in late
April. Sawchuk describes the fragment as a burnt piece of carbon fiber with an aluminum honeycomb
structure inside. This is not the first time SpaceX fragments have fallen to Earth. In 2022,
pieces of the SpaceX Crew-1 mission fell in Australia... And recently, a debris fragment
from the International Space Station fell on a house in Florida. The number of objects in
orbit is increasing dramatically. And this is something that absolutely needs to be addressed!
Good News and Bad News from James Webb Telescope
Let's start with the bad news. It's a bit of a letdown regarding the hopes of finding traces
of alien life on K2-18b, the potentially habitable planet located 120 light-years away, which grabbed
global attention in 2020 for its theoretically favorable conditions for hosting life forms.
A study published in The Astrophysical Journal Letters by researchers from the University
of California, Riverside, asserts that the potential life signatures observed by Webb
are not reliable. K2-18b, a planet with a mass 8.6 times that of Earth orbiting a cool dwarf star,
has long been considered one of the most interesting candidates for the search for
alien life. It resides in the so-called habitable zone, at a distance from its star that allows
for an "acceptable" temperature, coupled with the presence of vast oceans of water.
Recent observations by the Webb Space Telescope, particularly those published in November 2023,
caught attention because they identified the presence of dimethyl sulfide in the atmosphere,
a molecule produced by oceanic phytoplankton on Earth. One of Webb's remarkable capabilities is
analyzing the chemical composition of the atmospheres of distant planets. However,
the signal from K2-18b was very weak and intermittent. Researchers conducted simulations to
determine if the signal, which, if positive, would have been a significant indicator of alien life,
could be an artifact. Unfortunately, the results were not promising. The signal
indicating the presence of dimethyl sulfide heavily overlapped with that of methane,
making it unreadable even for a sophisticated instrument like the James Webb Telescope.
In short, it seems that Webb wasn't up to the task in this case. But don't worry, because there's
also good news. It appears that Webb has confirmed the presence of an atmosphere around 55 Cancri,
a rocky planet also known as Janssen, located 41 light-years away from us. It has a very dense
atmosphere composed mainly of carbon monoxide and carbon dioxide—a mixture not suitable for our
lungs, nor anything else, really. Conditions on this planet are extremely harsh; many indications
suggest that its surface is completely covered by a sea of lava. The planet orbits very close
to its smaller Sun-like star, always showing the same side, much like the Moon does to Earth. This
results in a significant temperature difference between the always-illuminated and always-shaded
sides, estimated at around 1,300 degrees. It seems that the atmosphere is emitted from
the magma oceans. However, as the researchers emphasize, the data needs to be confirmed
by new observations. They hope to point Webb's instruments again to observe the planet's future
transits in front of its star. The moment just before the planet is covered by the star is indeed
ideal for studying its atmospheric composition. So, one day we lose, and another day we win.
Even the James Webb Space Telescope has to battle against all sorts of difficulties. Perhaps we were
too hasty in christening it as "the instrument that would revolutionize astronomy"? Who knows.
Chang'e 6 in Lunar Orbit, Awaiting Descent to Surface
Did you know? On May 3rd, the Chinese robotic mission Chang'e 6 embarked on a
journey aiming to retrieve samples from the far side of the Moon for the first
time. After a five-day journey, on May 8th, the probe successfully entered lunar orbit,
where it currently awaits its descent to the surface with a lander set to touch
down in the Apollo crater, within the vast South Pole-Aitken Basin.
The mission architecture mirrors that of Chang'e 5, which successfully returned 1,731 grams of
lunar soil from the northern Oceanus Procellarum in the fall of 2020, located on the visible face
of the Moon. The significance of this mission lies in the fact that all lunar soil samples
returned to Earth so far were collected from the visible side of our natural satellite. Retrieving
soil from the far side of the Moon is considered a priority because this region is markedly different
from the visible face, and no satisfactory explanation for this difference has been found.
According to the mission schedule, the lander is expected to separate from the main probe and
touch down on the surface in early June. So why the long wait? It's simple—the Sun is about to
set on the far side of the Moon, and it will be dark until the end of May. After 14 days,
a new lunar day will begin, allowing the probe to descend to the surface.
Once the landing is executed and the rock samples collected as planned,
they will be transferred aboard the ascent module, which is scheduled to depart from
the Moon in mid-June. The return to Earth is currently slated for June 25th. If all robotic
operations proceed smoothly, the samples will be placed in orbit after four days. Two weeks later,
the main probe will ignite its thrusters for the return journey to Earth, with the mission
presumably concluding on June 25th with a landing in Inner Mongolia, a northern region of China.
It's fair to say that China has stepped into the role of the USA's competitor in
the space race, replacing Russia in this regard.
Okay, folks, we're wrapped up for the week. What
do you think? Which news story caught your attention the most?