James Webb Space Telescope (JWST)
-
- Posts: 13562
- Joined: Sun May 16, 2021 6:16 pm
-
- Posts: 13562
- Joined: Sun May 16, 2021 6:16 pm
Re: James Webb Space Telescope (JWST)
James Webb Space Telescope Might Be Able to Detect Alien Agriculture
By Ryan Whitwam on April 25, 2022 at 7:30 am
https://www.extremetech.com/extreme/334 ... griculture
By Ryan Whitwam on April 25, 2022 at 7:30 am
https://www.extremetech.com/extreme/334 ... griculture
If you were an alien looking at Earth from a great distance, it would have looked mostly the same right up until 10,000 years ago. That’s when humans invented agriculture, and the planet has never been the same since. Farming allowed humans to proliferate, and the scale at which we now produce food has changed the way Earth would appear to an outside observer. The same could be true of an inhabited exoplanet, and it just so happens we finally have a tool that could detect these conditions: the James Webb Space Telescope. A team of astronomers recently explained how the new observatory might be able to spot “exofarms” when it begins scanning the heavens later this year.
A study exploring this possibility is available on the preprint arXiv server. It comes courtesy of the Blue Marble Space Institute of Science in collaboration with NASA’s Goddard Space Flight Center and the University of California. The analysis assumes a few things about agriculture on exoplanets, including that the biosphere would take advantage of the free energy raining down from their suns. If there’s something like photosynthesis, then the large-scale farming of plants would produce recognizable signatures as it does on Earth.
Re: James Webb Space Telescope (JWST)
![Laughing :lol:](./images/smilies/icon_lol.gif)
![Laughing :lol:](./images/smilies/icon_lol.gif)
![Laughing :lol:](./images/smilies/icon_lol.gif)
To know is essentially the same as not knowing. The only thing that occurs is the rearrangement of atoms in your brain.
-
- Posts: 13562
- Joined: Sun May 16, 2021 6:16 pm
Re: James Webb Space Telescope (JWST)
Examining the heart of Webb: The final phase of commissioning
https://phys.org/news/2022-05-heart-web ... oning.html
by Scott Friedman, NASA
https://phys.org/news/2022-05-heart-web ... oning.html
by Scott Friedman, NASA
NASA's James Webb Space Telescope is now experiencing all seasons—from hot to cold—as it undergoes the thermal stability test. Meanwhile, activities are underway for the final phase of commissioning: digging into the details of the science instruments, the heart of Webb. To complete commissioning, we will measure the detailed performance of the science instruments before we start routine science operations in the summer.
Today, the lead commissioning scientist for Webb, Scott Friedman of the Space Telescope Science Institute (STScI), gives us all the details on this final phase of commissioning.
"With the telescope beautifully aligned and the observatory near its final cryogenic temperature, we are ready to begin the last group of activities before the science observations start: science instrument commissioning. Here I describe just a few of those activities.
"The instruments, the Near-Infrared Camera (NIRCam), Near-Infrared Spectrometer (NIRSpec), Near-Infrared Imager and Slitless Spectrometer (NIRISS), Mid-Infrared Instrument (MIRI), and the Fine Guidance Sensor (FGS) have been powered up and safely cooled. We have operated their mechanisms and detectors, including filter wheels, grating wheels, and the NIRSpec microshutter assembly. The Webb optics team used images of isolated stars taken with each of the instruments to align the primary and secondary mirrors of the observatory. But we have more work to do before Webb is fully ready to embark on the ambitious science observations that will reveal the secrets of the universe.
Re: James Webb Space Telescope (JWST)
How the James Webb Space Telescope Beat all Expectations
by Ethan Siegel
May 2, 2022
https://bigthink.com/starts-with-a-bang ... 1651475855
Introduction:
![Image](https://bigthink.com/wp-content/uploads/2021/12/https___specials-images.forbesimg.com_imageserve_59396209a7ea434078d4dda4_Every-planet-orbiting-a-star-has-five-location-around-it-Lagrange-points-that_960x0.jpg?resize=768,672)
Every planet orbiting a star has five location around it, Lagrange points, that co-orbit. An object precisely located at L1, L2, L3, L4, or L5 will continue to orbit the Sun with precisely the same period as Earth does, meaning that the Earth-spacecraft distance will be constant. L1, L2, and L3 are unstable points of equilibrium, requiring periodic course corrections to maintain a spacecraft’s position there, while L4 and L5 are stable. Webb successfully inserted itself in orbit around L2, and must always face away from the Sun for cooling purposes.
Credit: NASA
by Ethan Siegel
May 2, 2022
https://bigthink.com/starts-with-a-bang ... 1651475855
Introduction:
(Big Think) On Christmas Day of 2021, the James Webb Space Telescope was launched from Earth into space. With an expected 6-month deployment, the mission's plan was to begin science operations afterward and to have a 5-to-10 year science lifetime. At every turn, however, the Webb Telescope team has beaten expectations. After barely 4 months, it's practically ready, with perhaps 20 years of science ahead of it.
On December 25, 2021, the James Webb Space Telescope rocketed into space.
The plan envisioned six months of deployment, cooling, and calibration.
Afterwards, science operations would commence, yielding a 5-to-10 year anticipated lifetime.
Yet on April 28, 2022, each instrument’s alignment was completed, with a ~20 year lifetime expected.
![Image](https://bigthink.com/wp-content/uploads/2021/12/https___specials-images.forbesimg.com_imageserve_59396209a7ea434078d4dda4_Every-planet-orbiting-a-star-has-five-location-around-it-Lagrange-points-that_960x0.jpg?resize=768,672)
Every planet orbiting a star has five location around it, Lagrange points, that co-orbit. An object precisely located at L1, L2, L3, L4, or L5 will continue to orbit the Sun with precisely the same period as Earth does, meaning that the Earth-spacecraft distance will be constant. L1, L2, and L3 are unstable points of equilibrium, requiring periodic course corrections to maintain a spacecraft’s position there, while L4 and L5 are stable. Webb successfully inserted itself in orbit around L2, and must always face away from the Sun for cooling purposes.
Credit: NASA
Don't mourn, organize.
-Joe Hill
-Joe Hill
-
- Posts: 13562
- Joined: Sun May 16, 2021 6:16 pm
Re: James Webb Space Telescope (JWST)
Webb telescope nearly set to explore the solar system
https://phys.org/news/2022-05-webb-tele ... solar.html
by Thaddeus Cesari, NASA's Goddard Space Flight Center
https://phys.org/news/2022-05-webb-tele ... solar.html
by Thaddeus Cesari, NASA's Goddard Space Flight Center
As NASA's James Webb Space Telescope moves through the final phases of commissioning its science instruments, we have also begun working on technical operations of the observatory. While the telescope moves through space, it will constantly find distant stars and galaxies and point at them with extreme precision to acquire images and spectra. However, we also plan to observe planets and their satellites, asteroids, and comets in our solar system, which move across the background stars of our galaxy.
Webb needs to be able to lock on to these objects and track them with sufficient precision to obtain images and spectra. The Webb team recently completed the first test to track a moving object. The test verified that Webb could conduct moving target science. As we move forward through commissioning, we will test other objects moving at various speeds to verify we can study objects with Webb that move throughout the solar system.
Today, we asked Heidi Hammel, Webb interdisciplinary scientist for solar system observations, to tell us about her plans for studying Earth's nearest neighbors:
-
- Posts: 13562
- Joined: Sun May 16, 2021 6:16 pm
Re: James Webb Space Telescope (JWST)
Geology from 50 Light-Years: Webb Gets Ready to Study Rocky Worlds
https://www.nasa.gov/feature/goddard/20 ... cky-worlds
https://www.nasa.gov/feature/goddard/20 ... cky-worlds
Imagine if Earth were much, much closer to the Sun. So close that an entire year lasts only a few hours. So close that gravity has locked one hemisphere in permanent searing daylight and the other in endless darkness. So close that the oceans boil away, rocks begin to melt, and the clouds rain lava.
While nothing of the sort exists in our own solar system, planets like this—rocky, roughly Earth-sized, extremely hot and close to their stars—are not uncommon in the Milky Way galaxy.
What are the surfaces and atmospheres of these planets really like? NASA’s James Webb Space Telescope is about to provide some answers.
With its mirror segments beautifully aligned and its scientific instruments undergoing calibration, NASA’s James Webb Space Telescope is just weeks away from full operation. Soon after the first observations are revealed this summer, Webb’s in-depth science will begin.
Among the investigations planned for the first year are studies of two hot exoplanets classified as “super-Earths” for their size and rocky composition: the lava-covered 55 Cancri e and the airless LHS 3844 b. Researchers will train Webb’s high-precision spectrographs on these planets with a view to understanding the geologic diversity of planets across the galaxy, and the evolution of rocky planets like Earth.
Super-Hot Super-Earth 55 Cancri e
55 Cancri e orbits less than 1.5 million miles from its Sun-like star (one twenty-fifth of the distance between Mercury and the Sun), completing one circuit in less than 18 hours. With surface temperatures far above the melting point of typical rock-forming minerals, the day side of the planet is thought to be covered in oceans of lava.
Planets that orbit this close to their star are assumed to be tidally locked, with one side facing the star at all times. As a result, the hottest spot on the planet should be the one that faces the star most directly, and the amount of heat coming from the day side should not change much over time.
But this doesn’t seem to be the case. Observations of 55 Cancri e from NASA’s Spitzer Space Telescope suggest that the hottest region is offset from the part that faces the star most directly, while the total amount of heat detected from the day side does vary.
Does 55 Cancri e Have a Thick Atmosphere?
One explanation for these observations is that the planet has a dynamic atmosphere that moves heat around. “55 Cancri e could have a thick atmosphere dominated by oxygen or nitrogen,” explained Renyu Hu of NASA’s Jet Propulsion Laboratory in Southern California, who leads a team that will use Webb’s Near-Infrared Camera (NIRCam) and Mid-Infrared Instrument (MIRI) to capture the thermal emission spectrum of the day side of the planet. “If it has an atmosphere, [Webb] has the sensitivity and wavelength range to detect it and determine what it is made of,” Hu added.
Or Is It Raining Lava in the Evening on 55 Cancri e?
Another intriguing possibility, however, is that 55 Cancri e is not tidally locked. Instead, it may be like Mercury, rotating three times for every two orbits (what’s known as a 3:2 resonance). As a result, the planet would have a day-night cycle.
“That could explain why the hottest part of the planet is shifted,” explained Alexis Brandeker, a researcher from Stockholm University who leads another team studying the planet. “Just like on Earth, it would take time for the surface to heat up. The hottest time of the day would be in the afternoon, not right at noon.”
Brandeker’s team plans to test this hypothesis using NIRCam to measure the heat emitted from the lit side of 55 Cancri e during four different orbits. If the planet has a 3:2 resonance, they will observe each hemisphere twice and should be able to detect any difference between the hemispheres.
Re: James Webb Space Telescope (JWST)
James Webb Space Telescope hit by tiny meteoroid
By Jonathan Amos
BBC Science Correspondent
1 hour ago
A tiny rock fragment has hit the new James Webb Space Telescope's main mirror.
The damage inflicted by the dust-sized micrometeoroid is producing a noticeable effect in the observatory's data but is not expected to limit the mission's overall performance.
James Webb was launched in December to succeed the revolutionary - but now ageing - Hubble Space Telescope.
Astronomers are due to release its first views of the cosmos on 12 July.
The US space agency Nasa said these images would be no less stunning because of what's just happened.
https://www.bbc.co.uk/news/science-environment-61744257
![Image](https://ichef.bbci.co.uk/news/976/cpsprodpb/10395/production/_125335466_segment_damage-nc.png)
By Jonathan Amos
BBC Science Correspondent
1 hour ago
A tiny rock fragment has hit the new James Webb Space Telescope's main mirror.
The damage inflicted by the dust-sized micrometeoroid is producing a noticeable effect in the observatory's data but is not expected to limit the mission's overall performance.
James Webb was launched in December to succeed the revolutionary - but now ageing - Hubble Space Telescope.
Astronomers are due to release its first views of the cosmos on 12 July.
The US space agency Nasa said these images would be no less stunning because of what's just happened.
https://www.bbc.co.uk/news/science-environment-61744257
![Image](https://ichef.bbci.co.uk/news/976/cpsprodpb/10395/production/_125335466_segment_damage-nc.png)