JWST Lab
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Astronomy
Date
Dec 6, 2023
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10
Uploaded by ProfStrawCapybara76
JWST Lab
11/12/23
Cam Seymour
1) Name at least 3 of the stated scientific goals for the JWST.
The James Webb Space Telescope (JWST) has several scientific goals,
and three of them are: First Light and Reionization, JWST aims to detect the first
galaxies that formed after the Big Bang and study the processes involved in the
reionization of the universe. Reionization is the process through which the early
universe's neutral hydrogen gas became ionized. Assembly of Galaxies, The
telescope is designed to study the assembly and evolution of galaxies over
cosmic time. By observing galaxies at different stages of their formation and
development, scientists hope to gain insights into the underlying processes that
led to the diverse range of galaxies we observe today. Birth of Stars and
Protoplanetary Systems, JWST will investigate the formation of stars and
planetary systems. It will peer through the dusty regions of space where stars are
born, providing a clearer view of the earliest stages of stellar and planetary
formation.
2) Name at least 5 major discoveries it has already made since it was fully
calibrated in July of last year and after it got to its orbit at the L2 point in the
sun-earth system.
Five major discoveries it has made are it confirmed the Universes expansion
rate, captured an image of stars being born in the Pillars Of Creation, JWST
confirmed that exoplanet LHS 475 b is a planet and that it is 99 percent Earth’s
size, it has captured distant galaxies in Padoras Cluster, and It has discovered
ices in a dark cloud (the Chamaeleon I Molecular Cloud)
3) What is the L2 point? Name a few other space telescopes in that orbit. Where
are the other 4 LaGrangian points in the sun-earth system?
The Lagrange points are positions in space where the gravitational forces of a
two-body system, like the Earth and the Moon or the Earth and the Sun, combine
to provide enhanced regions of attraction and repulsion. There are five Lagrange
points in the Earth-Sun system, often denoted as L1 through L5. The L2 point, or
the second Lagrange point, is a point in space located on the line defined by the
two large bodies beyond the smaller of the two. In the case of the Earth-Sun
system, the L2 point is located beyond the Earth, opposite the Sun. Other space
telescopes that have been or are planned to be positioned at the L2 point include
the Herschel Space Observatory, Planck Observatory and, Gaia.
The other four Lagrange points in the Earth-Sun system are the L1 (First
Lagrange Point) between the Earth and the Sun, on the line defined by the two
bodies, L3 (Third Lagrange Point) opposite the Earth on the line defined by the
two bodies but not commonly used for space missions, L4 (Fourth Lagrange
Point) along the orbit of the smaller body, 60 degrees ahead of the smaller body,
and the L5 (Fifth Lagrange Point) along the orbit of the smaller body, 60 degrees
behind the smaller body. These Lagrange points are stable locations where
spacecraft can maintain their relative positions with respect to the Earth and the
Sun, making them advantageous for various space missions.
4) How long was it designed to last? Why do they think it may last up to 4 times
longer? What might they be able to do to outlive even that time limitation?
The JWST was designed to last 5 years with a goal for 10 years but now after
completion they believe it may last up to 20 years and possible beyond. The think
it could last that long because of the amount of propellant that they have in the
JWST but a factor that may change the lifespan is instrument degradation.
5) What is the wavelength range of infrared radiation?
The wavelength range of infrared (IR) radiation spans from approximately 700
nanometers (nm) to 1 millimeter (mm).
6) Name some benefits of looking at the universe in infrared instead of visible
light.
Observing the universe in infrared light provides several benefits compared to
visible light observations. Some of these advantages include penetration of Dust
and Gas, infrared radiation can penetrate dusty regions of space that may
obscure the view in visible light. Observation of Cool Objects, infrared
observations are crucial for studying cool objects, such as brown dwarfs,
exoplanets, and cold interstellar clouds. Detection of Redshifted Light, as the
universe expands, light from distant objects is redshifted, moving towards longer
wavelengths. Infrared observations are well-suited for detecting and studying
these redshifted objects, providing insights into the early universe and the
formation of galaxies. Study of Thermal Emission, many objects in space emit
strongly in the infrared due to their thermal radiation. Infrared observations are
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essential for studying the heat emitted by celestial bodies, including planets,
stars, and galaxies. Study of Exoplanets, infrared observations are valuable for
studying exoplanets by detecting their thermal radiation. Finally, piercing Through
Cosmic Fog, infrared light can penetrate through the cosmic fog created by the
abundance of neutral hydrogen in the early universe. There are many others as
well but these are just some of benefits.
7) Briefly explain the currently accepted 13.7 billion year history of the universe.
Why has JWST already cast some serious doubt on this theory?
The currently accepted model for the history of the universe is the Big Bang
theory. The universe is thought to have originated from a hot and dense state
approximately 13.7 billion years ago in an event known as the Big Bang. The
universe has been expanding ever since. During the first few minutes after the
Big Bang, the universe was hot enough for nuclear fusion to occur, leading to the
formation of light elements like hydrogen, helium, and small traces of other light
elements. Over time, gravitational forces caused matter to clump together,
forming structures such as galaxies, galaxy clusters, and cosmic filaments. About
380,000 years after the Big Bang, the universe cooled enough for neutral atoms
to form, allowing photons to travel freely. This event left behind the cosmic
microwave background radiation, a faint glow that permeates the universe. The
universe continues to expand, and the rate of expansion has been influenced by
the presence of dark matter and dark energy. The JWST has cast serious doubt
on this theory because it has discovered galaxies that would have grown too
massive too soon and that is something that would cast a lot of doubt to the big
bang theory.
8) How hot is the side facing the sun and how cold are the detectors on the other
side? How did they accomplish this nearly 600 degree difference? Why do
infrared detectors need to be kept so cold?
The maximum temperature of the side facing the sun is an estimated 383 K and
the cold detectors on the other side are a minimum of 36 K. They accomplish this
by having a sunshield that protects the instruments from the incredible heat from
the sun. The detectors need to be kept so cold so the telescope can observe the
infrared light and if the detectors were warm the only thing it could see would be
itself.
9) What is the mirror size and mass of the JWST compared to HST (Hubble
Space Telescope)
The James Webb Space Telescope’s primary mirror is 6.5 meters (21 feet
4-inches) acrossand the Hubble Space Telescope’s primary mirror is 2.4 meters
(8-feet) across and the JWST has about half of the mass of the Hubble
telescope.
10)Where does the HST orbit the earth? Why is it in that orbit?
The Hubble Space Telescope (HST) orbits the Earth in low Earth orbit (LEO) at
an altitude of approximately 547 kilometers (about 340 miles). Its orbit is
characterized by its relatively low altitude, allowing it to observe astronomical
objects with high resolution. While the Hubble Space Telescope has been highly
successful and has provided invaluable contributions to astronomy, it's worth
noting that its low Earth orbit also comes with limitations. For example, it cannot
observe the entire sky, and its observations are affected by the passage of the
Earth, which can limit continuous observations of certain objects. Despite these
limitations, Hubble's orbit has been well-suited for its mission objectives and has
allowed it to capture stunning images and conduct groundbreaking scientific
research.
11)What were some of the deployment challenges for the JWST?
The deployment challenges were aligning the telescope once it go into space as
well as unfolding the sunshield on the telescope as it had to be unfolded and they
couldn’t really test how it would unfold in space after it was launched.
12)Exactly when and from where on Earth was JWST finally launched after many
delays for this 10 billion-dollar marvel of human engineering and cooperation?
That is only just over 1 dollar for each of the 8 billion people currently living on
Earth. We all own part of this telescope since it was funded by NASA which gets
about 20 billion dollars a year of our taxpayers money. By comparison, our
defense budget is almost 1 trillion dollars a year. So this entire wonderful
telescope that will greatly elevate our view of the entire universe that we all live in
costs less than 5 DAYS worth of our taxpayers money used on our defense
budget! We can be very proud of what is has already discovered in just over one
year and look forward to what it may discover over the next 20 years or so. The
HST changed and expanded our limited view of the universe forever and now
JWST will continue and add to those great earth-shaking discoveries so that
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none of us should ever again feel as limited as we did before we knew what kind
of an amazing universe all of us REALLY live in!
he Webb was launched on 25 December 2021at 7:40 AM on an Ariane 5 rocket
from Kourou, French Guiana. In January 2022 it arrived at its destination, a solar
orbit near the Sun–Earth L
2
Lagrange point, about 1.5 million kilometers (930,000
mi) from Earth
13)What is the weight of all of Teledyne’s infrared detectors on board JWST?
The mass of the NIRspec detector is 196 kg. I could not find the rest of the
detectors weights.
14)How much energy in the form of photons will the JWST collect over 5 years?
(Refer to the clever demo with the M&M’s!) It is 10 to the 16 electron volts, a
TINY amount of energy. Radio waves have even LESS energy. The combined
effect of ALL the radio waves that ever hit the earth since radio telescopes were
invented in 1937 by Grote Reber is equivalent to the energy of one single
snowflake gently settling in the snow!
15)How are the 18 hexagonal mirror segments, each one 4.3 feet in diameter
holding up against micrometeorites?
From what I found they are holding up quite well against the micrometeorites as
they for the most part have all been within the range that they expected. There
have been a few that have been larger than expected but they can counteract
some of the effects from them.
16)What are the mirrors made of and what are they coated with to become more
reflective?
The mirrors are made of beryllium and coated with a thin layer of gold to
maximise reflectivity.
17)Briefly describe the intricate and involved process that creates the great
images that get published from the JWST. Each image requires over 600 stacked
images!
Observation Planning, astronomers and scientists plan observations based on
the scientific goals and targets of the telescope. The planning includes selecting
specific celestial objects, determining exposure times, and considering
instrument configurations.
Data Collection, the telescope observes the selected targets, collecting data in
the form of raw images or spectroscopic data. The data obtained are initially in a
digital format and may require calibration to correct for instrumental effects,
noise, and other factors.
Calibration, raw data from the telescope undergo various calibration processes to
correct for instrumental artifacts, such as bias, dark current, and flat-field
corrections. These calibrations ensure that the final images accurately represent
the astronomical objects being observed.
Data Processing, once calibrated, the data undergo additional processing to
enhance scientific features and visual aesthetics. This can include image
stacking, color balancing, and other techniques to highlight specific details in the
observations.
Image Combination and Enhancement, multiple images, often taken with
different filters or at different wavelengths, may be combined to create composite
images. These images can provide a more comprehensive view of the
astronomical object, revealing details that might not be apparent in individual
images.
Scientific Analysis, scientists analyze the processed images to extract
meaningful information about the observed objects. This analysis may involve
measuring the brightness, composition, distance, and other characteristics of
celestial bodies.
Publication, once the images are processed and analyzed, selected results are
prepared for publication. This involves creating visually appealing images that
convey scientific information effectively. Images are often annotated with relevant
details and are accompanied by scientific explanations and context.
Public Release, the final, processed images are released to the public through
various channels, including press releases, scientific journals, and official mission
websites. These images contribute to public outreach, education, and the
dissemination of scientific discoveries.
18)What is your favorite image so far and why?
My favorite image that I saw on the website is the image of
Rho Ophiuchi. I like it
because it looks like something that a concept artist would draw but it is actually
something that is real and out there in the universe which is really cool.
19)Discuss any other aspects of his talk or the questions afterwards that you
would like to share.
I thought his talk was very informational and I really learned quite a bit about the
JWST and I thought that it was interesting that he went to Fairfield and really fell
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in love with Physics there as opposed to many other people who work in this field
who say they have always loved astronomy and physics.