We can agree that nebulae are some of the most majestic-looking objects in the universe. But what are they exactly? Nebulae are giant clouds of gas and dust in space. They’re commonly associated with two parts of the life cycle of stars: First, they can be nurseries forming new baby stars. Second, expanding clouds of gas and dust can mark where stars have died.
Not all nebulae are alike, and their different appearances tell us what’s happening around them. Since not all nebulae emit light of their own, there are different ways that the clouds of gas and dust reveal themselves. Some nebulae scatter the light of stars hiding in or near them. These are called reflection nebulae and are a bit like seeing a street lamp illuminate the fog around it.
In another type, called emission nebulae, stars heat up the clouds of gas, whose chemicals respond by glowing in different colors. Think of it like a neon sign hanging in a shop window!
Finally there are nebulae with dust so thick that we’re unable to see the visible light from young stars shine through it. These are called dark nebulae.
Our missions help us see nebulae and identify the different elements that oftentimes light them up.
The Hubble Space Telescope is able to observe the cosmos in multiple wavelengths of light, ranging from ultraviolet, visible, and near-infrared. Hubble peered at the iconic Eagle Nebula in visible and infrared light, revealing these grand spires of dust and countless stars within and around them.
The Chandra X-ray Observatory studies the universe in X-ray light! The spacecraft is helping scientists see features within nebulae that might otherwise be hidden by gas and dust when viewed in longer wavelengths like visible and infrared light. In the Crab Nebula, Chandra sees high-energy X-rays from a pulsar (a type of rapidly spinning neutron star, which is the crushed, city-sized core of a star that exploded as a supernova).
The James Webb Space Telescope will primarily observe the infrared universe. With Webb, scientists will peer deep into clouds of dust and gas to study how stars and planetary systems form.
The Spitzer Space Telescope studied the cosmos for over 16 years before retiring in 2020. With the help of its detectors, Spitzer revealed unknown materials hiding in nebulae — like oddly-shaped molecules and soot-like materials, which were found in the California Nebula.
Studying nebulae helps scientists understand the life cycle of stars. Did you know our Sun got its start in a stellar nursery? Over 4.5 billion years ago, some gas and dust in a nebula clumped together due to gravity, and a baby Sun was born. The process to form a baby star itself can take a million years or more!
After billions more years, our Sun will eventually puff into a huge red giant star before leaving behind a beautiful planetary nebula (so-called because astronomers looking through early telescopes thought they resembled planets), along with a small, dense object called a white dwarf that will cool down very slowly. In fact, we don’t think the universe is old enough yet for any white dwarfs to have cooled down completely.
Since the Sun will live so much longer than us, scientists can’t observe its whole life cycle directly … but they can study tons of other stars and nebulae at different phases of their lives and draw conclusions about where our Sun came from and where it’s headed. While studying nebulae, we’re seeing the past, present, and future of our Sun and trillions of others like it in the cosmos.
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From nearby clouds of gas and dust to remote galaxies that formed billions of years ago, tour the night sky with our Hubble Space Telescope’s new Caldwell catalog. The catalog of star clusters, galaxies and nebulas was first produced to highlight cosmic wonders visible to amateur astronomers. Since then Hubble has taken images of 95 out of the 109 objects, bringing these objects to life in exquisite detail.
While the objects can be observed using modest ground-based telescopes, Hubble’s Caldwell collection has been assembled for astronomers to see the finer details of each object in the night sky.
That star stuff you see here? That’s what you’re made of. You possess the elements ✨
This composite image from our Chandra X-ray Observatory, the Spitzer Space Telescope and the Isaac Newton Telescope shows high-energy X-rays emitted by young, massive stars in the star cluster Cygnus OB2. This year we’re celebrating the 20th anniversary of Chandra’s launch. Want to dive deeper? Click here
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On July 23, 1999, NASA’s Chandra X-ray Observatory, the most powerful X-ray telescope ever built, was launched into space. Since then, Chandra has made numerous amazing discoveries, giving us a view of the universe that is largely hidden from view through telescopes that observe in other types of light.
The technology behind X-ray astronomy has evolved at a rapid pace, producing and contributing to many spinoff applications you encounter in day-to-day life. It has helped make advancements in such wide-ranging fields as security monitoring, medicine and bio-medical research, materials processing, semi-conductor and microchip manufacturing and environmental monitoring.
7:00 am: Your hand has been bothering you ever since you caught that ball at the family reunion last weekend. Your doctor decides it would be a good idea for an X-ray to rule out any broken bones. X-rays are sent through your hand and their shadow is captured on a detector behind it. You’re relieved to hear nothing is broken, though your doctor follows up with an MRI to make sure the tendons and ligaments are OK.
Two major developments influenced by X-ray astronomy include the use of sensitive detectors to provide low dose but high-resolution images, and the linkage with digitizing and image processing systems. Because many diagnostic procedures, such as mammographies and osteoporosis scans, require multiple exposures, it is important that each dosage be as low as possible. Accurate diagnoses also depend on the ability to view the patient from many different angles. Image processing systems linked to detectors capable of recording single X-ray photons, like those developed for X-ray astronomy purposes, provide doctors with the required data manipulation and enhancement capabilities. Smaller hand-held imaging systems can be used in clinics and under field conditions to diagnose sports injuries, to conduct outpatient surgery and in the care of premature and newborn babies.
8:00 am: A technician places your hand in a large cylindrical machine that whirs and groans as the MRI is taken. Unlike X-rays that can look at bones and dense structures, MRIs use magnets and short bursts of radio waves to see everything from organs to muscles.
MRI systems are incredibly important for diagnosing a whole host of potential medical problems and conditions. X-ray technology has helped MRIs. For example, one of the instruments developed for use on Chandra was an X-ray spectrometer that would precisely measure the energy signatures over a key range of X-rays. In order to make these observations, this X-ray spectrometer had to be cooled to extremely low temperatures. Researchers at our Goddard Space Flight Center in Greenbelt, Maryland developed an innovative magnet that could achieve these very cold temperatures using a fraction of the helium that other similar magnets needed, thus extending the lifetime of the instrument’s use in space. These advancements have helped make MRIs safer and require less maintenance.
11:00 am: There’s a pharmacy nearby so you head over to pick up allergy medicine on the way home from your doctor’s appointment.
X-ray diffraction is the technique where X-ray light changes its direction by amounts that depend on the X-ray energy, much like a prism separates light into its component colors. Scientists using Chandra take advantage of diffraction to reveal important information about distant cosmic sources using the observatory’s two gratings instruments, the High Energy Transmission Grating Spectrometer (HETGS) and the Low Energy Transmission Grating Spectrometer (LETGS).
X-ray diffraction is also used in biomedical and pharmaceutical fields to investigate complex molecular structures, including basic research with viruses, proteins, vaccines and drugs, as well as for cancer, AIDS and immunology studies. How does this work? In most applications, the subject molecule is crystallized and then irradiated. The resulting diffraction pattern establishes the composition of the material. X-rays are perfect for this work because of their ability to resolve small objects. Advances in detector sensitivity and focused beam optics have allowed for the development of systems where exposure times have been shortened from hours to seconds. Shorter exposures coupled with lower-intensity radiation have allowed researchers to prepare smaller crystals, avoid damage to samples and speed up their data runs.
12:00 pm: Don’t forget lunch. There’s not much time after your errands so you grab a bag of pretzels. Food safety procedures for packaged goods include the use of X-ray scans to make sure there is quality control while on the production line.
Advanced X-ray detectors with image displays inspect the quality of goods being produced or packaged on a production line. With these systems, the goods do not have to be brought to a special screening area and the production line does not have to be disrupted. The systems range from portable, hand-held models to large automated systems. They are used on such products as aircraft and rocket parts and structures, canned and packaged foods, electronics, semiconductors and microchips, thermal insulations and automobile tires.
2:00 pm: At work, you are busy multi-tasking across a number of projects, running webinar and presentation software, as well as applications for your calendar, spreadsheets, word processing, image editing and email (and perhaps some social media on the side). It’s helpful that your computer can so easily handle running many applications at once.
X-ray beam lithography can produce extremely fine lines and has applications for developing computer chips and other semiconductor related devices. Several companies are researching the use of focused X-ray synchrotron beams as the energy source for this process, since these powerful beams produce good pattern definition with relatively short exposure times. The grazing incidence optics — that is, the need to skip X-rays off a smooth mirror surface like a stone across a pond and then focus them elsewhere — developed for Chandra were the highest precision X-ray optics in the world and directly influenced this work.
7:00 pm: Dream vacation with your family. Finally! You are on your way to the Bahamas to swim with the dolphins. In the line for airport security, carry-on bags in hand, you are hoping you’ve remembered sunscreen. Shoes off! All items placed in the tray. Thanks to X-ray technology, your bags will be inspected quickly and you WILL catch your plane…
The first X-ray baggage inspection system for airports used detectors nearly identical to those flown in the Apollo program to measure fluorescent X-rays from the Moon. Its design took advantage of the sensitivity of the detectors that enabled the size, power requirements and radiation exposure of the system to be reduced to limits practical for public use, while still providing adequate resolution to effectively screen baggage. The company that developed the technology later developed a system that can simultaneously image, on two separate screens, materials of high atomic weight (e.g. metal hand guns) and materials of low atomic weight (e.g. plastic explosives) that pass through other systems undetected. Variations of these machines are used to screen visitors to public buildings around the world.
Imagine slow-motion fireworks that started exploding 170 years ago and are still continuing. This type of firework is not launched into Earth’s atmosphere, but rather into space by a doomed super-massive star, called Eta Carinae.
Halloween is just around the corner. Need some chilling décor? We’ve got you – and your walls – covered with three new Galaxy of
Horrors posters that showcase some of the most terrifying topics in the
universe.
Gamma Ray Ghouls
In the depths of the universe, the cores of two collapsed
stars violently merge to release a burst of the deadliest and most powerful
form of light, known as gamma rays. These beams of doom are unleashed upon
their unfortunate surroundings, shining a billion trillion times brighter than
the Sun for up to 30 terrifying seconds. No spaceship will shield you from their
blinding destruction!
Galactic Graveyard
The chillingly haunted galaxy called MACS 2129-1
mysteriously stopped making stars only a few billion years after the Big Bang.
It became a cosmic cemetery, illuminated by the red glow of decaying stars.
Dare to enter and you might encounter the frightening corpses of exoplanets or
the final death throes of once-mighty stars.
Dark Matter
Something strange and mysterious creeps throughout the
cosmos. Scientists call it dark matter. It is scattered in an intricate web
that forms the skeleton of our universe. Dark matter is invisible, only
revealing its presence by pushing and pulling on objects we can see. NASA’s Roman
Space Telescope will investigate its secrets. What will it find?
Download the full set in English and Spanish here.
Andrew J. Feustel was selected by NASA in 2000. The Lake Orion, Michigan native has a Ph.D. in the Geological Sciences, specializing in Seismology, and is a veteran of three spaceflights. In 2009, Dr. Feustel served on space shuttle mission STS-125. That mission was the fifth and final mission to service the Hubble Space Telescope that improved the observatory’s capabilities through 2014! Feustel most recently served as Commander on the International Space Station from March 21 through October 4, 2018. In his free time, Dr. Feustel enjoys auto restoration, guitar, water and snow skiing and is a fan of automotive and motorcycle racing.
He took some time from his job as a NASA astronaut to answer a few questions about his life and career! Enjoy:
While attending Oakland Community College, you worked as an auto mechanic. How does that job and the skills you learned relate to your job now as an astronaut?
I’ve often told people that I believe having this skillset is almost as important as my training in college and university. I relied on those skills almost every day in space and even on the ground while preparing for missions. That skillset has been really helpful in understanding how to maintain and repair equipment for spaceflight. In general, having those general skills of knowing how things fit together, what the structure is, and how things work, even without knowing anything about the particular item, is very helpful in life.
Has there ever been a time as a NASA Astronaut where you had to overcome self-doubt and if so, how did you?
Yes, probably the most impactful time I had to overcome self-doubt was on my very first mission as a rookie doing a spacewalk for the first time and having to make a repair on the Hubble Space Telescope. Since it was my first spacewalk, I didn’t know if I could do it and didn’t know how I would do. However, I had trained for that mission for three years and the training took over when I started the spacewalk. At that point, I didn’t focus on my self-doubt, I focused on my training and was able to carry out the tasks.
What are you most excited about for the upcoming Artemis Moon missions?
I am most excited about the possibility of humans establishing the ability to live off of our planet. To have the capability to exist on another surface. That, to me, is a start. Humans need that capability for us to live on the Moon then to go to Mars.
What did living in space teach you about community and teamwork?
Not just living in space, but working at NASA and training for space missions taught me a lot about community and teamwork. Living in space allows you to use the skills you learn about teamwork while training. While living in space you must rely on each other for everything. It’s important to recognize the value of working as a team. All of the astronauts have a very different mix of skills and that’s a great thing about the astronaut corps. Being successful and staying alive in space relies on community and teamwork.
What kind of impact did living and working in space have on how you view the Earth?
I am more aware of the fragility of our planet and species which is why humans should extend past the Earth. We are fragile as a planet and the Earth is vulnerable to the impacts of us living here. We cannot have zero impact on the planet, we will always have some impact, but the goal is to lessen the damage that we do to Earth to allow us to live here indefinitely if possible.
What or who inspired you to apply to be an astronaut?
I was inspired by reading the obituary of my great-great uncle. He was very successful in the utilities and railroad industry in the Midwest. Reading about his successes made me believe that I could do anything. I was also interested in space travel from a young age. I believed that I would be involved in the space industry. The motivation of understanding what family members had done before me really encouraged me to reach for my dreams and apply.
What book, movie, or show about space and/or astronauts is the most accurate? The least accurate? You wish was accurate?
I’m less concerned about the accuracy of space and space exploration portrayed in movies, but more interested with the creative thought behind them and I am fascinated with ideas and imagination of the people making these movies. Things portrayed as science fiction in the past become science fact in the future.
What’s the most common misconception about astronauts / working at NASA?
The most common misconception about astronauts is that we go on spaceflights often. Over 95% of our job is spent working on the ground. People should come to this job because it’s important to space and space exploration. The job entails so much more than going into space yourself, but the good news is it’s all awesome. I have never been bored at my job. There are so many exciting parts of this work that contribute to NASA missions even if it doesn’t always mean being in space.
Can you share your favorite photo or video that you took in space?
My favorite photo is this one of Michigan and Canada. It captures my life – where I lived and everyone that I know and my family and friends – that’s where I consider home. It’s such a beautiful image.
That’s a wrap! Thank you Dr. Feustel for your time!
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This nebula began forming about 10,000 years ago when a dying star started flinging material into space. When Sun-like stars exhaust their nuclear fuel, they become unstable and blast their outer layers of gas away into space (bad news for any planets in the area). This Hubble Space Telescope image shows a snapshot of the unworldly process.
Streams of high-energy ultraviolet radiation cause the expelled material to glow, creating a beautiful planetary nebula — a term chosen for the similarity in appearance to the round disk of a planet when viewed through a small telescope.
The Eskimo Nebula got its nickname because it resembles a face surrounded by a fur parka. The “parka” is a disk of material embellished by a ring of comet-shaped objects with their tails streaming away from the central, dying star. In the middle of the nebula is a bubble of material that is being blown outward by the star’s intense “wind” of high-speed material.
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Astronomers used three of NASA’s Great Observatories to capture this multiwavelength image showing galaxy cluster IDCS J1426.5+3508. It includes X-rays recorded by the Chandra X-ray Observatory in blue, visible light observed by the Hubble Space Telescope in green, and infrared light from the Spitzer Space Telescope in red. This rare galaxy cluster has important implications for understanding how these megastructures formed and evolved early in the universe.
How Astronomers Time Travel
Let’s add another item to your travel bucket list: the early universe! You don’t need the type of time machine you see in sci-fi movies, and you don’t have to worry about getting trapped in the past. You don’t even need to leave the comfort of your home! All you need is a powerful space-based telescope.
But let’s start small and work our way up to the farthest reaches of space. We’ll explain how it all works along the way.
Meet BurstCube! This shoebox-sized satellite is designed to study the most powerful explosions in the cosmos, called gamma-ray bursts. It detects gamma rays, the highest-energy form of light.
BurstCube may be small, but it had a huge journey to get to space.
