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NASA shuts down the incredible Spitzer Space Telescope
Goodnight, sweet Spitzer.
- One of NASA's most important telescopes has been put to sleep in space.
- The infrared Spitzer Space telescope made a number of science-shaking discoveries over the course of its 16-year lifespan.
- Without Spitzer, we wouldn't know about the TRAPPIST-1 exoplanets.
It was one of NASA's four Great Observatories. Each of the telescopes was tuned to its own wavelength of light, watching the universe in its own way. Together, the quartet presented to scientists a universe of unprecedented detail. There was the Hubble Space Telescope, the Chandra X-ray Observatory, the Compton Gamma Ray Observatory, and the Spitzer Space Telescope, capturing infrared light. Last Thursday, at 2:30 p.m. PST, Spitzer was decommissioned after 16 years of invaluable observations, and 11 years after its original mission ended. It now continues to orbit the Sun in safe mode some 266,600,037 kilometers from Earth.
While not as well-known as other telescopes, particularly the Hubble, Spitzer's contributions were nonetheless equally as important. According to NASA's Thomas Zurbuchen, "Spitzer has taught us about entirely new aspects of the cosmos and taken us many steps further in understanding how the universe works, addressing questions about our origins, and whether or not are we alone." Moreover, Zurbuchen points out, "This Great Observatory has also identified some important and new questions and tantalizing objects for further study, mapping a path for future investigations to follow. Its immense impact on science certainly will last well beyond the end of its mission."
Spitzer will be replaced by the Webb telescope, launching in 2021.
Spitzer, take a bow
Spitzer image of the Tarantula Nebula
Image source: NASA/JPL-Caltech
Spitzer weighs about 865 kilograms (nearly a ton) and is about 4 meters tall. For its sensors to detect infrared light, their temperature control is critical — they have to operate at about 5 degrees above absolute zero (That's -450 F or -268 C). Other equipment on the telescope needs to be relatively warms, so its body is divided into the frigid Cryogenic Telescope Assembly and the spacecraft itself.
In the Cryogenic Telescope Assembly is a 0.85-meter telescope, as well as a multiple instrument chamber containing the Infrared Array Camera, the Infrared Spectrograph, the Multiband Imaging Photometer, and the Cryostat, in addition to the Outer-Shell Group. The Assembly was cooled with liquid helium, though by the end of the original mission in 2009 it had been depleted. Since that time, just two of the Infrared Array Camera's four wavelength bands have been scanning the stars.
The spacecraft itself contains what you'd expect: navigation, communication, solar panels, and so on.
Representation of Trappist-1 system
Image source: NASA/JPL-Caltech
Probably the most famous of Spitzer's accomplishment is its discovery of the TRAPPIST-1 exoplanets, seven Earth-sized bodies orbiting a single star. Three of them occupy the habitable zone around their sun, which is a bit cooler than ours, and are potentially capable of supporting life. Spitzer provided some 500 hours-worth of observations of the TRAPPIST-1 system.
Big mature galaxies as seen by Spitzer in an early universe
Image source: NASA/JPL-Caltech/ESA
Spitzer was especially good at detecting distant, ancient young galaxies. The oldest infrared light it captured was from about 13.4 billion years ago, just 400 million years after the universe's birth. Spitzer also revealed and identified a set of "big baby" galaxies that were unexpectedly well-developed for their relative youth — the implication being that larger galaxies may not have resulted from collisions of smaller ones after all, but came together quickly on their own in the early days of the universe.
Great buckyballs in space!
Artist rendering of NGC 2440 nebula
Image source: NASA/JPL-Caltech
Buckyballs are spherical carbon molecules whose hexagon-pentagon-patterned surfaces make them look like soccer balls. They belong to a molecule class called buckminsterfullerenes, named after the famous dome-shaped buildings designed by architect Buckminster Fuller. Spitzer found buckyballs in space orbiting a dying star called Tc 1.
So much more
The final ovation
Image source: NASA/JPL-Caltech
Spitzer's been incredibly productive over the years, and NASA's compiled a page of 15 of its most notable accomplishments. "Everyone who has worked on this mission should be extremely proud today," said Spitzer Project Manager Joseph Hunt. "There are literally hundreds of people who contributed directly to Spitzer's success, and thousands who used its scientific capabilities to explore the universe. We leave behind a powerful scientific and technological legacy."
- Why are so many objects in space shaped like discs? - Big Think ›
- How fast is Earth moving through space? That depends. - Big Think ›
These alien-like creatures are virtually invisible in the deep sea.
- A team of marine biologists used nets to catch 16 species of deep-sea fish that have evolved the ability to be virtually invisible to prey and predators.
- "Ultra-black" skin seems to be an evolutionary adaptation that helps fish camouflage themselves in the deep sea, which is illuminated by bioluminescent organisms.
- There are likely more, and potentially much darker, ultra-black fish lurking deep in the ocean.
The Pacific blackdragon
Credit: Karen Osborn/Smithsonian<p>When researchers first saw the deep-sea species, it wasn't immediately obvious that their skin was ultra-black. Then, marine biologist Karen Osborn, a co-author on the new paper, noticed something strange about the photos she took of the fish.</p><p style="margin-left: 20px;">"I had tried to take pictures of deep-sea fish before and got nothing but these really horrible pictures, where you can't see any detail," Osborn told <em><a href="https://www.wired.com/story/meet-the-ultra-black-vantafish/" target="_blank">Wired</a></em>. "How is it that I can shine two strobe lights at them and all that light just disappears?"</p><p>After examining samples of fish skin under the microscope, the researchers discovered that the fish skin contains a layer of organelles called melanosomes, which contain melanin, the same pigment that gives color to human skin and hair. This layer of melanosomes absorbs most of the light that hits them.</p>
A crested bigscale
Credit: Karen Osborn/Smithsonian<p style="margin-left: 20px;">"But what isn't absorbed side-scatters into the layer, and it's absorbed by the neighboring pigments that are all packed right up close to it," Osborn told <em>Wired</em>. "And so what they've done is create this super-efficient, very-little-material system where they can basically build a light trap with just the pigment particles and nothing else."</p><p>The result? Strange and terrifying deep-sea species, like the crested bigscale, fangtooth, and Pacific blackdragon, all of which appear in the deep sea as barely more than faint silhouettes.</p>
David Csepp, NMFS/AKFSC/ABL<p>But interestingly, this unique disappearing trick wasn't passed on to these species by a common ancestor. Rather, they each developed it independently. As such, the different species use their ultra-blackness for different purposes. For example, the threadfin dragonfish only has ultra-black skin during its adolescent years, when it's rather defenseless, as <em>Wired</em> <a href="https://www.wired.com/story/meet-the-ultra-black-vantafish/" target="_blank">notes</a>.</p><p>Other fish—like the <a href="http://onebugaday.blogspot.com/2016/06/a-new-anglerfish-oneirodes-amaokai.html" target="_blank">oneirodes species</a>, which use bioluminescent lures to bait prey—probably evolved ultra-black skin to avoid reflecting the light their own bodies produce. Meanwhile, species like <em>C. acclinidens</em> only have ultra-black skin around their gut, possibly to hide light of bioluminescent fish they've eaten.</p><p>Given that these newly described species are just ones that this team found off the coast of California, there are likely many more, and possibly much darker, ultra-black fish swimming in the deep ocean. </p>
Using machine-learning technology, the genealogy company My Heritage enables users to animate static images of their relatives.
- Deep Nostalgia uses machine learning to animate static images.
- The AI can animate images by "looking" at a single facial image, and the animations include movements such as blinking, smiling and head tilting.
- As deepfake technology becomes increasingly sophisticated, some are concerned about how bad actors might abuse the technology to manipulate the pubic.
My Heritage/Deep Nostalgia<p>But that's not to say the animations are perfect. As with most deep-fake technology, there's still an uncanny air to the images, with some of the facial movements appearing slightly unnatural. What's more, Deep Nostalgia is only able to create deepfakes of one person's face from the neck up, so you couldn't use it to animate group photos, or photos of people doing any sort of physical activity.</p>
My Heritage/Deep Nostalgia<p>But for a free deep-fake service, Deep Nostalgia is pretty impressive, especially considering you can use it to create deepfakes of <em>any </em>face, human or not. </p>
How long should one wait until an idea like string theory, seductive as it may be, is deemed unrealistic?
- How far should we defend an idea in the face of contrarian evidence?
- Who decides when it's time to abandon an idea and deem it wrong?
- Science carries within it its seeds from ancient Greece, including certain prejudices of how reality should or shouldn't be.
Plato used the allegory of the cave to explain that what humans see and experience is not the true reality.
Credit: Gothika via Wikimedia Commons CC 4.0<p>When scientists and mathematicians use the term <em>Platonic worldview</em>, that's what they mean in general: The unbound capacity of reason to unlock the secrets of creation, one by one. Einstein, for one, was a believer, preaching the fundamental reasonableness of nature; no weird unexplainable stuff, like a god that plays dice—his tongue-in-cheek critique of the belief that the unpredictability of the quantum world was truly fundamental to nature and not just a shortcoming of our current understanding. Despite his strong belief in such underlying order, Einstein recognized the imperfection of human knowledge: "What I see of Nature is a magnificent structure that we can comprehend only very imperfectly, and that must fill a thinking person with a feeling of humility." (Quoted by Dukas and Hoffmann in <em>Albert Einstein, The Human Side: Glimpses from His Archives</em> (1979), 39.)</p> <p>Einstein embodies the tension between these two clashing worldviews, a tension that is still very much with us today: On the one hand, the Platonic ideology that the fundamental stuff of reality is logical and understandable to the human mind, and, on the other, the acknowledgment that our reasoning has limitations, that our tools have limitations and thus that to reach some sort of final or complete understanding of the material world is nothing but an impossible, <a href="https://www.amazon.com/dp/B01K2JTGIA?tag=bigthink00-20&linkCode=ogi&th=1&psc=1" target="_blank" rel="noopener noreferrer">semi-religious dream</a>.</p>