If You Have A "smart" Mobile Phone, Then You Have A Digital Camera In Your Pocket, Backpack Or Purse.
If you have a "smart" mobile phone, then you have a digital camera in your pocket, backpack or purse. The camera sensor built into these phones provide high resolution images that are captured in a digital format readily displayed, saved and shared with others. This same technology is now being built into flexible scopes for inspecting the internal channels of medical devices. This approach to flexible scope design offers a number of advantages over traditional fiber optics.
First, and foremost, is an incredible improvement of the image quality. With fiber optics, as the number of glass fibers are reduced, the resolution or quality of the image is also reduced. In very small bundles, below 5mm in diameter, the image can be blurry. Conversely, with the use of modern digital camera technology, the optical imaging sensor is actually placed right at the tip of the scope, delivering a clear, well defined image.
Another issue often experienced with fiber optics, is their delicate nature. A fiber optic scope has thousands of individual strands of glass. These strands are very delicate and when flexed and bent, they easily break. Not so with modern digital camera technology. The only thing running through the shaft of these flexible inspection scopes are wires that relay the bits and bytes from the image sensor at the tip - and deliver the power to that image sensor as well as the LED light also located at the tip.
Power and lighting bring up another important advancement made possible by digital imaging technology - unlike with traditional fiber optic systems that require a separate light source and some kind of individually powered camera coupling mechanism - the digital imaging technology found in flexible inspection scopes, including the lighting, camera and image capturing system, are all powered by the USB port of a desktop or laptop computer.
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Infrared is Beautiful
Why was James Webb Space Telescope designed to observe infrared light? How can its images hope to compare to those taken by the (primarily) visible-light Hubble Space Telescope? The short answer is that Webb will absolutely capture beautiful images of the universe, even if it won’t see exactly what Hubble sees. (Spoiler: It will see a lot of things even better.)
The James Webb Space Telescope, or Webb, is our upcoming infrared space observatory, which will launch in 2019. It will spy the first luminous objects that formed in the universe and shed light on how galaxies evolve, how stars and planetary systems are born, and how life could form on other planets.
What is infrared light?
This may surprise you, but your remote control uses light waves just beyond the visible spectrum of light—infrared light waves—to change channels on your TV.
Infrared light shows us how hot things are. It can also show us how cold things are. But it all has to do with heat. Since the primary source of infrared radiation is heat or thermal radiation, any object that has a temperature radiates in the infrared. Even objects that we think of as being very cold, such as an ice cube, emit infrared.
There are legitimate scientific reasons for Webb to be an infrared telescope. There are things we want to know more about, and we need an infrared telescope to learn about them. Things like: stars and planets being born inside clouds of dust and gas; the very first stars and galaxies, which are so far away the light they emit has been stretched into the infrared; and the chemical fingerprints of elements and molecules in the atmospheres of exoplanets, some of which are only seen in the infrared.
In a star-forming region of space called the ‘Pillars of Creation,’ this is what we see with visible light:
And this is what we see with infrared light:
Infrared light can pierce through obscuring dust and gas and unveil a more unfamiliar view.
Webb will see some visible light: red and orange. But the truth is that even though Webb sees mostly infrared light, it will still take beautiful images. The beauty and quality of an astronomical image depends on two things: the sharpness of the image and the number of pixels in the camera. On both of these counts, Webb is very similar to, and in many ways better than, Hubble. Webb will take much sharper images than Hubble at infrared wavelengths, and Hubble has comparable resolution at the visible wavelengths that Webb can see.
Webb’s infrared data can be translated by computer into something our eyes can appreciate – in fact, this is what we do with Hubble data. The gorgeous images we see from Hubble don’t pop out of the telescope looking fully formed. To maximize the resolution of the images, Hubble takes multiple exposures through different color filters on its cameras.
The separate exposures, which look black and white, are assembled into a true color picture via image processing. Full color is important to image analysis of celestial objects. It can be used to highlight the glow of various elements in a nebula, or different stellar populations in a galaxy. It can also highlight interesting features of the object that might be overlooked in a black and white exposure, and so the images not only look beautiful but also contain a lot of useful scientific information about the structure, temperatures, and chemical makeup of a celestial object.
This image shows the sequences in the production of a Hubble image of nebula Messier 17:
Here’s another compelling argument for having telescopes that view the universe outside the spectrum of visible light – not everything in the universe emits visible light. There are many phenomena which can only be seen at certain wavelengths of light, for example, in the X-ray part of the spectrum, or in the ultraviolet. When we combine images taken at different wavelengths of light, we can get a better understanding of an object, because each wavelength can show us a different feature or facet of it.
Just like infrared data can be made into something meaningful to human eyes, so can each of the other wavelengths of light, even X-rays and gamma-rays.
Below is an image of the M82 galaxy created using X-ray data from the Chandra X-ray Observatory, infrared data from the Spitzer Space Telescope, and visible light data from Hubble. Also note how aesthetically pleasing the image is despite it not being just optical light:
Though Hubble sees primarily visible light, it can see some infrared. And despite not being optimized for it, and being much less powerful than Webb, it still produced this stunning image of the Horsehead Nebula.
It’s a big universe out there – more than our eyes can see. But with all the telescopes now at our disposal (as well as the new ones that will be coming online in the future), we are slowly building a more accurate picture. And it’s definitely a beautiful one. Just take a look…
…At this Spitzer infrared image of a shock wave in dust around the star Zeta Ophiuchi.
…this Spitzer image of the Helix Nebula, created using infrared data from the telescope and ultraviolet data from the Galaxy Evolution Explorer.
…this image of the “wing” of the Small Magellanic Cloud, created with infrared data from Spitzer and X-ray data from Chandra.
…the below image of the Milky Way’s galactic center, taken with our flying SOFIA telescope. It flies at more than 40,000 feet, putting it above 99% of the water vapor in Earth’s atmosphere– critical for observing infrared because water vapor blocks infrared light from reaching the ground. This infrared view reveals the ring of gas and dust around a supermassive black hole that can’t be seen with visible light.
…and this Hubble image of the Mystic Mountains in the Carina Nebula.
Learn more about the James Webb Space Telescope HERE, or follow the mission on Facebook, Twitter and Instagram.
Image Credits Eagle Nebula: NASA, ESA/Hubble and the Hubble Heritage Team Hubble Image Processing - Messier 17: NASA/STScI Galaxy M82 Composite Image: NASA, CXC, JHU, D.Strickland, JPL-Caltech, C. Engelbracht (University of Arizona), ESA, and The Hubble Heritage Team (STScI/AURA) Horsehead Nebula: NASA, ESA, and The Hubble Heritage Team (STScI/AURA) Zeta Ophiuchi: NASA/JPL-Caltech Helix Nebula: NASA/JPL-Caltech Wing of the Small Magellanic Cloud X-ray: NASA/CXC/Univ.Potsdam/L.Oskinova et al; Optical: NASA/STScI; Infrared: NASA/JPL-Caltech Milky Way Circumnuclear Ring: NASA/DLR/USRA/DSI/FORCAST Team/ Lau et al. 2013 Mystic Mountains in the Carina Nebula: NASA/ESA/M. Livio & Hubble 20th Anniversary Team (STScI)
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Voyager: The Spacecraft
The twin Voyager 1 and 2 spacecraft are exploring where nothing from Earth has flown before. Continuing their more-than-40-year journey since their 1977 launches, they each are much farther away from Earth and the Sun than Pluto.
The primary mission was the exploration of Jupiter and Saturn. After making a string of discoveries there – such as active volcanoes on Jupiter’s moon Io and intricacies of Saturn’s rings – the mission was extended.
Voyager 2 went on to explore Uranus and Neptune, and is still the only spacecraft to have visited those outer planets. The adventurers’ current mission, the Voyager Interstellar Mission (VIM), will explore the outermost edge of the Sun’s domain. And beyond.
Spacecraft Instruments
‘BUS’ Housing Electronics
The basic structure of the spacecraft is called the “bus,” which carries the various engineering subsystems and scientific instruments. It is like a large ten-sided box. Each of the ten sides of the bus contains a compartment (a bay) that houses various electronic assemblies.
Cosmic Ray Subsystem (CRS)
The Cosmic Ray Subsystem (CRS) looks only for very energetic particles in plasma, and has the highest sensitivity of the three particle detectors on the spacecraft. Very energetic particles can often be found in the intense radiation fields surrounding some planets (like Jupiter). Particles with the highest-known energies come from other stars. The CRS looks for both.
High-Gain Antenna (HGA)
The High-Gain Antenna (HGA) transmits data to Earth on two frequency channels (the downlink). One at about 8.4 gigahertz, is the X-band channel and contains science and engineering data. For comparison, the FM radio band is centered around 100 megahertz.
Imaging Science Subsystem (ISS)
The Imaging Science Subsystem (ISS) is a modified version of the slow scan vidicon camera designed that were used in the earlier Mariner flights. The ISS consists of two television-type cameras, each with eight filters in a commandable Filter Wheel mounted in front of the vidicons. One has a low resolution 200 mm wide-angle lens, while the other uses a higher resolution 1500 mm narrow-angle lens.
Infrared Interferometer Spectrometer and Radiometer (IRIS)
The Infrared Interferometer Spectrometer and Radiometer (IRIS) actually acts as three separate instruments. First, it is a very sophisticated thermometer. It can determine the distribution of heat energy a body is emitting, allowing scientists to determine the temperature of that body or substance.
Second, the IRIS is a device that can determine when certain types of elements or compounds are present in an atmosphere or on a surface.
Third, it uses a separate radiometer to measure the total amount of sunlight reflected by a body at ultraviolet, visible and infrared frequencies.
Low-Energy Charged Particles (LECP)
The Low-Energy Charged Particles (LECP) looks for particles of higher energy than the Plasma Science instrument, and it overlaps with the Cosmic Ray Subsystem (CRS). It has the broadest energy range of the three sets of particle sensors.
The LECP can be imagined as a piece of wood, with the particles of interest playing the role of the bullets. The faster a bullet moves, the deeper it will penetrate the wood. Thus, the depth of penetration measures the speed of the particles. The number of “bullet holes” over time indicates how many particles there are in various places in the solar wind, and at the various outer planets. The orientation of the wood indicates the direction from which the particles came.
Magnetometer (MAG)
Although the Magnetometer (MAG) can detect some of the effects of the solar wind on the outer planets and moons, its primary job is to measure changes in the Sun’s magnetic field with distance and time, to determine if each of the outer planets has a magnetic field, and how the moons and rings of the outer planets interact with those magnetic fields.
Optical Calibration Target The target plate is a flat rectangle of known color and brightness, fixed to the spacecraft so the instruments on the movable scan platform (cameras, infrared instrument, etc.) can point to a predictable target for calibration purposes.
Photopolarimeter Subsystem (PPS)
The Photopolarimeter Subsystem (PPS) uses a 0.2 m telescope fitted with filters and polarization analyzers. The experiment is designed to determine the physical properties of particulate matter in the atmospheres of Jupiter, Saturn and the rings of Saturn by measuring the intensity and linear polarization of scattered sunlight at eight wavelengths.
The experiment also provided information on the texture and probable composition of the surfaces of the satellites of Jupiter and Saturn.
Planetary Radio Astronomy (PRA) and Plasma Wave Subsystem (PWS)
Two separate experiments, The Plasma Wave Subsystem and the Planetary Radio Astronomy experiment, share the two long antennas which stretch at right-angles to one another, forming a “V”.
Plasma Science (PLS)
The Plasma Science (PLS) instrument looks for the lowest-energy particles in plasma. It also has the ability to look for particles moving at particular speeds and, to a limited extent, to determine the direction from which they come.
The Plasma Subsystem studies the properties of very hot ionized gases that exist in interplanetary regions. One plasma detector points in the direction of the Earth and the other points at a right angle to the first.
Radioisotope Thermoelectric Generators (RTG)
Three RTG units, electrically parallel-connected, are the central power sources for the mission module. The RTGs are mounted in tandem (end-to-end) on a deployable boom. The heat source radioisotopic fuel is Plutonium-238 in the form of the oxide Pu02. In the isotopic decay process, alpha particles are released which bombard the inner surface of the container. The energy released is converted to heat and is the source of heat to the thermoelectric converter.
Ultraviolet Spectrometer (UVS)
The Ultraviolet Spectrometer (UVS) is a very specialized type of light meter that is sensitive to ultraviolet light. It determines when certain atoms or ions are present, or when certain physical processes are going on.
The instrument looks for specific colors of ultraviolet light that certain elements and compounds are known to emit.
Learn more about the Voyager 1 and 2 spacecraft HERE.
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