Studies have shown that pollution, whether from factories or traffic-snarled roads, disproportionately affects communities where economicall...
Monday, June 7, 2021
5 Scientific Revolutions That NASA’s James Webb Space Telescope Will Deliver
Cumulatively, astronomical data helps scientists reconstruct what happened in our Universe’s past.
Looking back a variety of distances corresponds to a variety of times since the Big Bang. While our ... [+] modern suite of observatories has taken us very far back in the distant Universe, numerous questions remain: both about what happened at very early times and also about details at later times that are obscure to us today.
NASA, ESA, AND A. FEILD (STSCI)
Despite the full suite of modern telescopes, our present data sets cannot answer every question.
The James Webb Space Telescope vs. Hubble in size (main) and vs. an array of other telescopes ... [+] (inset) in terms of wavelength and sensitivity. Its power is truly unprecedented.
NASA / JWST
Only observatories with superior capabilities will solve those mysteries.
One of the last tests that will be performed on NASA's James Webb is a final check of the mirror ... [+] deployment sequence in full. With all environmental stress testing now out of the way, these last checks will hopefully be routine, paving the way for a successful 2021 launch.
NASA / James Webb Space Telescope team
After years of development, NASA’s James Webb Space Telescope is now complete.
This 2017 launch of an Ariane 5 rocket mirrors the launch vehicle of NASA's James Webb Space ... [+] Telescope. The Ariane 5 had a string of more than 80 consecutive launch successes before a partial failure a few years ago. It is one of the most reliable launch vehicles in space history.
Although the data shown in this graph shows the duration of the launch window on each day throughout ... [+] a particular 18-month window, the physics of launching a rocket does not change on a year-to-year basis, and so similar (but not identical) figures are expected around the October 31, 2021 window.
The first stars in the Universe will be surrounded by neutral atoms of (mostly) hydrogen gas, which ... [+] absorbs the starlight. The hydrogen makes the Universe opaque to visible, ultraviolet, and a large fraction of near-infrared light, but longer wavelengths may yet be observable and visible to near-future observatories. The temperature during this time was not 3K, but hot enough to boil liquid nitrogen, and the Universe was tens of thousands of times denser than it is today on the large-scale average.
This artist's impression of an early, massive galaxy that forms from the merger of ... [+] smaller-protogalaxies shows how it should be obscured by dust during the most rapid phases of star-formation. James Webb's infrared eyes might allow it to penetrate this dust, revealing details of the earliest stars ever seen.
The most distant X-ray jet in the Universe, from quasar GB 1428, helps illustrate how bright these ... [+] fantastic objects are. If we can figure out how to use quasars to measure the expansion of the Universe, we can understand the nature of dark energy as never before.
X-ray: NASA/CXC/NRC/C.Cheung et al; Optical: NASA/STScI; Radio: NSF/NRAO/VLA
2.) How black holes form.The youngest quasars are already quite massive.
If you begin with an initial, seed black hole when the Universe was only 100 million years old, ... [+] there's a limit to the rate at which it can grow: the Eddington limit. Either these black holes start off bigger than our theories expect, form earlier than we realize, or they grow faster than our present understanding allows to achieve the mass values we observe.
Feige Wang, from AAS237
Webb should match quasars to host galaxies, uncovering black hole growth in the young Universe.
The spiral structure around the old, giant star R Sculptoris is due to winds blowing off outer ... [+] layers of the star as it undergoes its AGB phase, where copious amounts of neutrons (from carbon-13 + helium-4 fusion) are produced and captured. The spiral pattern likely points to a binary companion: something our Sun does not possess.
ALMA (ESO/NAOJ/NRAO)/M. Maercker et al.
3.) Stellar lifecycles. Stars in their death throes create heavy elements throughout the cosmos.
Extremely high-resolution ALMA images revealed a hot “blob” in the dusty core of Supernova 1987A ... [+] (inset), which could be the location of the missing neutron star. The red color shows dust and cold gas in the center of the supernova remnant, taken at radio wavelengths with ALMA. The green and blue hues reveal where the expanding shock wave from the exploded star is colliding with a ring of material around the supernova. James Webb will offer a view of objects such as this that will be superior in many ways.
ALMA (ESO/NAOJ/NRAO), P. Cigan and R. Indebetouw; NRAO/AUI/NSF, B. Saxton; NASA/ESA
The protoplanetary disk around the star HL Tauri in a young star cluster may well be the best ... [+] analogue of a Sun-like star forming, with planets around it, that we've ever seen. This was ALMA's first protoplanetary disk to display the rings and gaps, and over the past 4 years our knowledge of protoplanetary evolution has taken us ever closer to a complete understanding of these systems.
ALMA (ESO/NAOJ/NRAO)/NASA/ESA
4.) How planetary systems form. Protoplanetary disks are nature’s laboratory for planet formation.
The protostar IM Lup has a protoplanetary disk around it that exhibits not only rings, but a spiral ... [+] feature towards the center. There is likely a very massive planet causing these spiral features, but that has yet to be definitively confirmed. In the early stages of a solar system's formation, these protoplanetary disks cause dynamical friction, causing young planets to spiral inwards rather than complete perfect, closed ellipses.
S. M. Andrews et al. and the DSHARP collaboration, arXiv:1812.04040
Direct imaging of four planets orbiting the star HR 8799 129 light years away from Earth, a feat ... [+] accomplished through the work of Jason Wang and Christian Marois. The second generation of stars may have already had rocky planets orbiting them, and more distant planets can be resolved with direct imaging. Webb's coronagraph will take us closer.
J. Wang (UC Berkeley) & C. Marois (Herzberg Astrophysics), NExSS (NASA), Keck Obs.
The exoplanet Proxima b, as shown in this artist's illustration, is thought to be inhospitable to ... [+] life due to the atmosphere-stripping behavior of its star. It should be an 'eyeball' world, where one side always roasts in the Sun and the other side always remains frozen. With a telescope like James Webb, direct imaging and spectroscopic measurements, including a search for CO2, should be possible.
The atmosphere of the exoplanet WASP-33b was examined as starlight filtered through the planet's ... [+] atmosphere before arriving at our eyes. Similar techniques could work for other exoplanets as well, but to image the atmosphere of Earth-sized planets, as opposed to the Jupiter-sized WASP-33b, we require observatories that are larger and more advanced than the ones we have today. NASA's James Webb Space Telescope will break all the transit spectroscopy size records we currently have today.
NASA / Goddard
Mostly Mute Monday tells an astronomical story in images, visuals, and no more than 200 words. Talk less; smile more.
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