Astronews Recent Space News Discoveries (James Webb Space Telescope, Ariane 5, Hubble, Mars…)

Welcome to the sixth review of “Space and Astronomy” news, selected for you by Insane
Curiosity Channel.
The news, which will be weekly, will try to provide a quick overview of everything interesting
happened in recent days in the field of astronomical research and space exploration.
Keep following us!
The
James Webb Space Telescope opened for the last time on Earth its primary mirror.
This test served to replicate again this specific operation, which the James Webb will perform
once it reaches space, moving six of its 18 hexagonal mirrors.
The mechanism of deployment of the side mirrors was one of the last tests in which every maneuver
that the telescope will perform was replicated.
The commands were the same ones that will be used in space.
To simulate the maneuver even better, the telescope was also in a simulated microgravity
condition.
During testing, all thermal coatings and shielding designed to protect the mirrors and instruments
from interference were also installed.
Performing the deployment maneuver of the side mirrors requires 132 different actuators,
which were tested one by one earlier this year.
They move each element to a different position with great precision.
This is necessary to ensure the fine-tuning process of the individual mirrors. after this
last mirror deployment test, there will be a few more tests left before it can be shipped
to the launch site.
These include testing the extension of two radiators, which are needed to cool the telescope,
and a full extension and retraction test of the James Webb’s central tower.
Once these tests are completed, the telescope will be ready for launch.
The James Webb Space Telescope will be launched to a specific location in space, the Lagrangian
point L2.
This point in space is located 1.5 million km from Earth in the opposite direction to
the Sun.
The choice of this particular position in the Solar System is rooted in the extreme
sensitivity of the instruments on board the telescope.
There, in fact, by turning the heat shield towards the Sun, Earth and Moon, it will be
able to point the mirror towards deep space sheltered from any thermal perturbation.
It will operate at a constant temperature of 220 degrees Celsius below zero.
To reach this position, the James Webb will be launched aboard a European Ariane V launcher
from the launch base in French Guiana.
This launcher, guaranteed by ESA as part of the European contribution to the telescope
itself, was chosen for its reliability and of course for its technical characteristics.
However, the Ariane V has a fairing, i.e. a cargo space, with a diameter of 5 meters,
while the James Webb, once extended, will have a diameter of 6.5 meters.
For this reason, the telescope will have to be bent in various ways to be inserted inside
the European launcher.
After years of delays, the James Webb Space Telescope is currently scheduled to depart
on October 31, 2021.
But, apparently, some bad news is on the way…
To find out which ones, keep following me.
A problem with the Ariane V could cause a new launch delay for the James Webb Space
Telescope.
The James Webb Space Telescope will be the most complex and advanced space telescope
ever built and launched by humans.
After many delays, which put off its launch by years, there is finally a fairly feasible
projected date: October 31, 2021.
Unfortunately, even this date looks like it will be skipped, for a launch in the following
months.
For the first time, however, the cause of the delay should not be due to the telescope,
but to the launch system, the European launcher Ariane V.
The Ariane V launcher was chosen for the launch of the American telescope as part of the European
contribution to the James Webb Space Telescope.
It was also chosen for its unique reliability record.
In fact, the last accident of this launcher was in 2002, which meant almost 19 years of
uninterrupted success.
Unfortunately, a problem appears to have surfaced with the fairing, the cover that protects
the cargo on top of the launcher.
Ariane V was last launched in August 2020 and is now waiting for this issue to be resolved
before returning to space.
Also, during the last two launches, vibrations were detected to the structure that holds
the satellites well above safe limits.
Despite everything, the cargo arrived at its destination without problems, but the thing
has obviously raised concerns about the launch of the James Webb Space Telescope.
The telescope is in fact one of the most expensive payloads ever launched into space, with a
budget that exceeded $9.8 billion.
And in these cases, as Gene Kranz said in Apollo 13, “failure is not an option!”.
The problem, however, is real, and NASA has admitted that it expects delays from the October
31, 2021 date, but has failed to quantify the extent of those delays.
Fixing the problems could take months as well as just a couple of weeks.
We’ll just have to cross our fingers…
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In 1.3 million years, a star will come within 24 light-days of the Sun
Within the Milky Way, there are an estimated 200 to 400 billion stars, all of which orbit
around the center of our galaxy in a coordinated cosmic dance.
As they orbit, stars in the galactic disk (where our Sun is located) periodically shuffle
about and get closer to one another.
At times, this can have a drastic effect on the star that experience a close encounter,
disrupting their systems and causing planets to be ejected.
Knowing when stars will make a close encounter with our Solar System, and how it might shake
up objects within it, is therefore a concern to astronomers.
Using data collected by the Gaia Observatory, two researchers with the Russian Academy of
Sciences determined that a handful of stars will be making close passes by our Solar System
in the future, one of which will stray pretty close!
As they indicated, they relied on astrometric data from the Gaia mission’s Early Data
Release 3, which revealed kinematic characteristics of stars that are expected to pass within
3.26 light-years (1 Parsec) with the Solar System in the future.
To start things off simple: our Solar System is composed of eight designated planets and
several minor (aka. dwarf) planets orbiting our main sequence G-type yellow dwarf Sun,
which is surrounded by an outer ring of icy objects known as the Kuiper Belt.
Beyond this, at a distance of roughly 1.63 light-years from the Sun (0.5 parsecs), is
a massive cloud of icy debris known as the Oort Cloud, which is where long-period comets
originate.
These comets are generally the result of objects making close flybys with the Solar System
and knocking objects loose, to the point that they periodically fly through the Solar System
and around the Sun before heading back out.
The outer edge of the Oort Cloud is estimated to be 0.5 parsecs (1.6 light-years) from our
Sun, which makes them particularly responsive to perturbations from a number of sources.
For astronomers, the process of searching for stars that may have flown by our Solar
System in the past (and which may pass us by in the future) began in the 1960s.
The research has improved as more sophisticated instruments have become available, leading
to more detailed catalogs on nearby celestial objects.
In order to know which stars will make a close encounter, you need to know their distance
and their three velocities.
The consists of the two properties of proper motion – right ascension, declination – and
radial velocity.
Once you have all that, you can conduct astrometry, which is the precise measurement of the positions
and movements of stars and other celestial bodies.
Thanks to the precise data, astronomers are able to determine which of them are likely
to make a close encounter in the future.
In the end, all methods yielded similar results: one star would be making a particularly close
encounter a little over a million years from now.
Better known as Gliese 710, this variable K-type orange dwarf star is about 60% as massive
as our Sun and located some 62 light-years from Earth in the Serpens constellation.
Specifically, the simulations conducted showed that Gliese 710 would be making its close
flyby 1.32 million years from now and would pass within 0.02 parsecs (just shy of 24 light
days) of our Sun.
Simulations have shown that Gliese 710 will make its close passage in 1.32 million years,
passing within 0.02 parsecs (just under 24 light days) of our Sun.
But what could happen to the Solar System and Earth?
Certainly, a star that manages to penetrate so deeply into the Solar System (24 light
days correspond to 4000 astronomical units, just a hundred times the distance that separates
us from Pluto) would bring significant changes in the orbital elements of the planets; but,
above all, it would cause great upheavals in the Oort Cloud, probably diverting a large
number of cometary bodies towards the inner Solar System.
On the Earth there could then be another “big bombardment”, as it happened billions of years
ago, and as it has probably happened other times in the past.
But who knows where our species will be in 1.3 million years?
Galaxies and gravitational lensing: a wonderful shot of Hubble
The Hubble team has released an incredibly beautiful shot of “ACO S 295”, a massive galaxy
cluster located some 3.5 billion light-years away in the small southern constellation of
Horologium.
The image is made up of observations from Hubble’s Wide Field Camera 3 and Advanced
Camera for Surveys in the infrared and optical parts of the spectrum.
Galaxy clusters contain thousands of galaxies, and typically, they have a mass of about one
million billion times the mass of the Sun.
Galaxies of all shapes and sizes populate this image, ranging from stately spirals to
fuzzy ellipticals.
As well as a range of sizes, this galactic menagerie boasts a range of orientations,
with spiral galaxies such as the one at the center of this image appearing almost face
on, and some edge-on spiral galaxies visible only as thin slivers of light.
However, there is something even more interesting to point out, and that is the “gravitational
lens” effect that can be perceived by looking carefully at the shape of larger objects.
Albert Einstein predicted in his theory of general relativity that massive objects will
deform the fabric of space itself, and in fact, the image shows how the huge mass of
the galaxy cluster has gravitationally lensed the background galaxies, distorting and smearing
their shapes.
Or even forming multiple images of the most distant object.
The observer may then see multiple distorted images of the same source.
Look in particular at the galaxy in the upper right corner…
It is traversed by a sinuous slice of light, which is nothing more than a galaxy behind
the first, whose image has been enlarged and deformed.
Try to think carefully about what you are looking at right now… all the little dots
of light in this image (apart from two or three little stars that are part of our Milky
Way) are Galaxies!
Thousands of galaxies all packed into a photographic field of just 2.4×2.0 arcminutes… that of
a 2 cm postage stamp viewed from a distance of about 30 meters!
There may still be active volcanoes on Mars?
Evidence of recent volcanic activity suggests that on Mars the last eruptions may have occurred
about 50,000 years ago.
This is revealed by a study signed by David Horvath of the Planetary Science Institute
Research.
Until now, most volcanic activity on the Red Planet was thought to have occurred between
3 and 4 billion years ago, with small isolated eruptions dated to 3 million years ago.
There had never been evidence that Mars was still geologically active.
However, by studying images provided by Martian orbiters, Horvath and a team of scientists
from the Lunar and Planetary Lab at the University of Texas found evidence of a recent eruption
in Elysium Planitia.
Elysium Planitia is the second largest volcanic region on Mars, after the Tharsis Mountains.
It includes, from north to south, the volcanoes Hercas Tholus, Elysium Mons, Albor Tholus,
the Cerberus Palus, and the Cerberus Fossae.
The volcanic deposit, analyzed by Horvath, is symmetrically distributed around a fissure
of the Cerberus Fossae and covers an area little larger than Washington, D.C.
To analyze the surface conformation and map the site’s craters, Horvath and colleagues
used photographic data from the Mars Reconnaissance Orbiter and derived estimates of thickness,
volume, and age.
Well… these values, it turns out, are morphologically consistent with a deposit of material erupted
from a volcano no more than 53,000 years ago!
This means that we could be facing the youngest volcanic deposit ever documented on Mars.
So recent that if we were to compress the geologic history of Mars into a single day,
such an eruption would have occurred in the last second.
Further evidence in our favor is provided by the instrumentation of InSight, the NASA
lander that has been studying tectonic activity on Mars since 2018.
In fact, the site of the recent eruption is 1,600 kilometers from where InSight revealed
two Marsquakes, and recent studies have suggested the possibility that these could be due to
magma movement at depth.
A volcanic deposit like this raises hopes that the Martian environment may harbor or
may have harbored life.
For example, the melting of subsurface ice caused by a volcanic eruption could generate
favorable conditions for habitable environments underground.
They would be analogous to places on Earth where volcanic activity occurs in glacial
environments such as Iceland, where chemotrophic, cryophilic and thermophilic bacteria thrive.
A little extra hope for those who still believe in life on Mars.
OK, guys… we’re done for the week too.
What do you think?
What news struck you the most?

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