What do we have planned for 2016? A return to the king of planets. A survey of mysterious Ceres. More postcards from Pluto. Anyone who follows solar system exploration in 2016 is in for quite a ride. Last year was one for the record books – and now here are 10 things to look forward to in the new year. See also: what we have planned agency wide for 2016.
Juno Arrives at Jupiter
July 4, 2016 is arrival day for the Juno mission, the first sent expressly to study the largest planet in the solar system since our Galileo mission in the 1990s. Humans have been studying Jupiter for hundreds of years, yet many basic questions about the gas world remain: How did it form? What is its internal structure? Exactly how does it generate its vast magnetic field? What can it tell us about the formation of other planets inside and outside our solar system? Beginning in July, we’ll be a little closer to the answers.
OSIRIS-REx Takes Flight
The OSIRIS-REx mission, short for Origins-Spectral Interpretation-Resource Identification-Security-Regolith Explorer, sets sail for an asteroid in September. The spacecraft will use a robotic arm to pluck samples from the asteroid Bennu to help better explain our solar system’s formation and even find clues to how life began.
Dawn Sees Ceres Up Close
After an odyssey of many years and millions of miles, in December the Dawn spacecraft entered its final, lowest mapping orbit around the dwarf planet Ceres. The intriguing world’s odd mountains, craters and salty deposits are ready for their close-ups. We can expect new images of the starkly beautiful surface for months.
Cassini Commences Its Grand Finale
In late 2016, the Cassini spacecraft will begin a daring set of orbits called the Grand Finale, which will be in some ways like a whole new mission. Beginning this year and extending into next, the spacecraft will repeatedly climb high above Saturn’s poles, flying just outside its narrow F ring 20 times. After a last targeted Titan flyby, the spacecraft will then dive between Saturn’s uppermost atmosphere and its innermost ring 22 times. As Cassini plunges past Saturn, the spacecraft will collect rich and valuable information far beyond the mission’s original plan.
New Horizons Sends More Postcards from Pluto
We have stared slack-jawed at the images and discoveries from last year’s Pluto flyby, but the fact is that most of the data that New Horizons collected remains on board the spacecraft. In 2016, we’ll see a steady release of new pictures — and very likely some expanded answers to longstanding questions.
Mars Missions March Forward
With five of our missions continuing their Martian quests, 2016 should be a good year for discoveries on the Red Planet.
A transit is a very rare astronomical event in which a planet passes across the face of the sun. In May, Mercury will transit the sun, on of only thirteen Mercury transits each century on average.
LRO Keeps an Eagle Eye On the Moon
The Lunar Reconnaissance Orbiter (LRO) will extend its run in 2016, scanning the moon’s surface with its sharp-eyed instruments, investigating everything from lava tube skylights to changes at the Apollo landing sites.
Spacecraft Fly Under Many Flags
Our partner agencies around the world will be flying several new or continuing planetary missions to destinations across the solar system:
Technology Demonstration Missions Push the Envelope
We’re always looking for new frontiers on distant worlds, as well as the technology that will take us there. This year, several missions are planned to take new ideas for a spin in space:
After traveling for two years and billions of kilometers from Earth, the OSIRIS-REx probe is only a few months away from its destination: the intriguing asteroid Bennu. When it arrives in December, OSIRIS-REx will embark on a nearly two-year investigation of this clump of rock, mapping its terrain and finding a safe and fruitful site from which to collect a sample.
The spacecraft will briefly touch Bennu’s surface around July 2020 to collect at least 60 grams (equal to about 30 sugar packets) of dirt and rocks. It might collect as much as 2,000 grams, which would be the largest sample by far gathered from a space object since the Apollo Moon landings. The spacecraft will then pack the sample into a capsule and travel back to Earth, dropping the capsule into Utah’s west desert in 2023, where scientists will be waiting to collect it.
This years-long quest for knowledge thrusts Bennu into the center of one of the most ambitious space missions ever attempted. But the humble rock is but one of about 780,000 known asteroids in our solar system. So why did scientists pick Bennu for this momentous investigation? Here are 10 reasons:
1. It’s close to Earth
Unlike most other asteroids that circle the Sun in the asteroid belt between Mars and Jupiter, Bennu’s orbit is close in proximity to Earth’s, even crossing it. The asteroid makes its closest approach to Earth every 6 years. It also circles the Sun nearly in the same plane as Earth, which made it somewhat easier to achieve the high-energy task of launching the spacecraft out of Earth’s plane and into Bennu’s. Still, the launch required considerable power, so OSIRIS-REx used Earth’s gravity to boost itself into Bennu’s orbital plane when it passed our planet in September 2017.
2.It’s the right size
Asteroids spin on their axes just like Earth does. Small ones, with diameters of 200 meters or less, often spin very fast, up to a few revolutions per minute. This rapid spinning makes it difficult for a spacecraft to match an asteroid’s velocity in order to touch down and collect samples. Even worse, the quick spinning has flung loose rocks and soil, material known as “regolith” — the stuff OSIRIS-REx is looking to collect — off the surfaces of small asteroids. Bennu’s size, in contrast, makes it approachable and rich in regolith. It has a diameter of 492 meters, which is a bit larger than the height of the Empire State Building in New York City, and rotating once every 4.3 hours.
3. It’s really old
Bennu is a leftover fragment from the tumultuous formation of the solar system. Some of the mineral fragments inside Bennu could be older than the solar system. These microscopic grains of dust could be the same ones that spewed from dying stars and eventually coalesced to make the Sun and its planets nearly 4.6 billion years ago. But pieces of asteroids, called meteorites, have been falling to Earth’s surface since the planet formed. So why don’t scientists just study those old space rocks? Because astronomers can’t tell (with very few exceptions) what kind of objects these meteorites came from, which is important context. Furthermore, these stones, that survive the violent, fiery decent to our planet’s surface, get contaminated when they land in the dirt, sand, or snow. Some even get hammered by the elements, like rain and snow, for hundreds or thousands of years. Such events change the chemistry of meteorites, obscuring their ancient records.
4.It’s well preserved
Bennu, on the other hand, is a time capsule from the early solar system, having been preserved in the vacuum of space. Although scientists think it broke off a larger asteroid in the asteroid belt in a catastrophic collision between about 1 and 2 billion years ago, and hurtled through space until it got locked into an orbit near Earth’s, they don’t expect that these events significantly altered it.
5. It might contain clues to the origin of life
Analyzing a sample from Bennu will help planetary scientists better understand the role asteroids may have played in delivering life-forming compounds to Earth. We know from having studied Bennu through Earth- and space-based telescopes that it is a carbonaceous, or carbon-rich, asteroid. Carbon is the hinge upon which organic molecules hang. Bennu is likely rich in organic molecules, which are made of chains of carbon bonded with atoms of oxygen, hydrogen, and other elements in a chemical recipe that makes all known living things. Besides carbon, Bennu also might have another component important to life: water, which is trapped in the minerals that make up the asteroid.
6. It contains valuable materials
Besides teaching us about our cosmic past, exploring Bennu close-up will help humans plan for the future. Asteroids are rich in natural resources, such as iron and aluminum, and precious metals, such as platinum. For this reason, some companies, and even countries, are building technologies that will one day allow us to extract those materials. More importantly, asteroids like Bennu are key to future, deep-space travel. If humans can learn how to extract the abundant hydrogen and oxygen from the water locked up in an asteroid’s minerals, they could make rocket fuel. Thus, asteroids could one day serve as fuel stations for robotic or human missions to Mars and beyond. Learning how to maneuver around an object like Bennu, and about its chemical and physical properties, will help future prospectors.
7. It will help us better understand other asteroids
Astronomers have studied Bennu from Earth since it was discovered in 1999. As a result, they think they know a lot about the asteroid’s physical and chemical properties. Their knowledge is based not only on looking at the asteroid, but also studying meteorites found on Earth, and filling in gaps in observable knowledge with predictions derived from theoretical models. Thanks to the detailed information that will be gleaned from OSIRIS-REx, scientists now will be able to check whether their predictions about Bennu are correct. This work will help verify or refine telescopic observations and models that attempt to reveal the nature of other asteroids in our solar system.
8. It will help us better understand a quirky solar force …
Astronomers have calculated that Bennu’s orbit has drifted about 280 meters (0.18 miles) per year toward the Sun since it was discovered. This could be because of a phenomenon called the Yarkovsky effect, a process whereby sunlight warms one side of a small, dark asteroid and then radiates as heat off the asteroid as it rotates. The heat energy thrusts an asteroid either away from the Sun, if it has a prograde spin like Earth, which means it spins in the same direction as its orbit, or toward the Sun in the case of Bennu, which spins in the opposite direction of its orbit. OSIRIS-REx will measure the Yarkovsky effect from close-up to help scientists predict the movement of Bennu and other asteroids. Already, measurements of how this force impacted Bennu over time have revealed that it likely pushed it to our corner of the solar system from the asteroid belt.
9. … and to keep asteroids at bay
One reason scientists are eager to predict the directions asteroids are drifting is to know when they’re coming too-close-for-comfort to Earth. By taking the Yarkovsky effect into account, they’ve estimated that Bennu could pass closer to Earth than the Moon is in 2135, and possibly even closer between 2175 and 2195. Although Bennu is unlikely to hit Earth at that time, our descendants can use the data from OSIRIS-REx to determine how best to deflect any threatening asteroids that are found, perhaps even by using the Yarkovsky effect to their advantage.
10. It’s a gift that will keep on giving
Samples of Bennu will return to Earth on September 24, 2023. OSIRIS-REx scientists will study a quarter of the regolith. The rest will be made available to scientists around the globe, and also saved for those not yet born, using techniques not yet invented, to answer questions not yet asked.
Read the web version of this week’s “Solar System: 10 Things to Know” article HERE.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.
The Ingenuity Mars Helicopter made history – not only as the first aircraft to perform powered, controlled flight on another world – but also for exceeding expectations, pushing the limits, and setting the stage for future NASA aerial exploration of other worlds.
Built as a technology demonstration designed to perform up to five experimental test flights over 30 days, Ingenuity performed flight operations from the Martian surface for almost three years. The helicopter ended its mission on Jan. 25, 2024, after sustaining damage to its rotor blades during its 72nd flight.
So, what did we learn from this small but mighty helicopter?
Our Milky Way galaxy is full of hundreds of billions of
worlds just waiting to be found. In 2014, scientists using data from our planet-hunting
Kepler space telescope discovered seven planets orbiting Kepler-90, a Sun-like star
located 2,500 light-years away. Now, an eighth planet has been identified in this
planetary system, making it tied with our own solar system in having the highest
number of known planets. Here’s what you need to know:
The new planet is called Kepler-90i.
Kepler-90i is a sizzling hot, rocky planet. It’s the smallest of eight planets in the Kepler-90 system. It orbits so close to its star that a “year” passes in just 14 days.
Average surface temperatures on Kepler-90i are estimated to hover around 800 degrees Fahrenheit, making it an unlikely place for life as we know it.
Its planetary system is like a scrunched up version of our solar system.
The Kepler-90 system is set up like our solar system, with the small planets located close to their star and the big planets farther away. This pattern is evidence that the system’s outer gas planets—which are about the size of Saturn and Jupiter—formed in a way similar to our own.
But the orbits are much more compact. The orbits of all eight
planets could fit within the distance of Earth’s orbit around our Sun! Sounds
crowded, but think of it this way: It would make for some great planet-hopping.
Kepler-90i was discovered using machine learning.
Most planets beyond our solar system are too far away to be imaged directly. The Kepler space telescope searches for these exoplanets—those planets orbiting stars beyond our solar system—by measuring how the brightness of a star changes when a planet transits, or crosses in front of its disk. Generally speaking, for a given star, the greater the dip in brightness, the bigger the planet!
Researchers trained a computer to learn how to identify the faint signal of transiting exoplanets in Kepler’s vast archive of deep-space data. A search for new worlds around 670 known multiple-planet systems using this machine-learning technique yielded not one, but two discoveries: Kepler-90i and Kepler-80g. The latter is part of a six-planet star system located 1,000 light-years away.
This
is just the beginning of a new way of planet hunting.
Kepler-90 is the first known star system besides our own that has eight planets, but scientists say it won’t be the last. Other planets may lurk around stars surveyed by Kepler. Next, researchers are using machine learning with sophisticated computer algorithms to search for more planets around 150,000 stars in the Kepler database.
In
the meantime, we’ll be doing more searching with telescopes.
Kepler is the most successful planet-hunting spacecraft to date, with more than 2,500 confirmed exoplanets and many more awaiting verification. Future space missions, like the Transiting Exoplanet Survey Satellite (TESS), the James Webb Space Telescope and Wide-Field Infrared Survey Telescope (WFIRST) will continue the search for new worlds and even tell us which ones might offer promising homes for extraterrestrial life.
Our solar system is huge, let us break it down for you. Here are a few things you should know this week:
1. Closeup of a King
For the first time since it entered orbit around Jupiter in July, our Juno spacecraft has flown close to the king of planets—this time with its eyes wide open. During the long, initial orbit, Juno mission managers spent time checking out the spacecraft “from stem to stern,” but the science instruments were turned off as a precaution. During this latest pass, Juno’s camera and other instruments were collecting data the whole time. Initial reports show that all went well, and the team has released a new close-up view that Juno captured of Jupiter’s north polar region. We can expect to see more close-up pictures of Jupiter and other data this week.
Our OSIRIS-REx mission leaves Earth next week, the first leg of a journey that will take it out to an asteroid called Bennu. The mission will map the asteroid, study its properties in detail, then collect a physical sample to send back home to Earth. The ambitious endeavor is slated to start off on Sept. 8.
The Lunar Reconnaissance Orbiter (LRO) has already mapped the entire surface of Earth’s moon in brilliant detail, but the mission isn’t over yet. Lunar explorers still have questions, and LRO is poised to help answer them.
We don’t have to wait until next year to see the moon cross in front of the sun. From its vantage point in deep space, our Solar Dynamics Observatory (SDO) sometimes sees just that. Such an event is expected on Sept. 1.
Our galaxy is home to a bewildering variety of Jupiter-like worlds: hot ones, cold ones, giant versions of our own giant, pint-sized pretenders only half as big around. Astronomers say that in our galaxy alone, a billion or more such Jupiter-like worlds could be orbiting stars other than our sun. And we can use them to gain a better understanding of our solar system and our galactic environment, including the prospects for finding life.
Want to learn more? Read our full list of the 10 things to know this week about the solar system HERE.
On October 20th, our OSIRIS-REx mission will make its first attempt to collect and
retrieve a sample of asteroid Bennu, a near-Earth asteroid. On sample
collection day, Bennu will be over 200 million miles away from Earth.
Asteroids are the building blocks of our solar system. A sample of this ancient material can tell us about the history of our planet and the origins of life. Science results published from the mission on October 8th confirm that Bennu contains carbon in a form often found in biology or in compounds associated with biology.
To collect a sample, OSIRIS-REx
will attempt a method NASA has never used before – called Touch-And-Go
(TAG). First, the spacecraft extends its robotic
sampling arm, the Touch-And-Go Sample Acquisition Mechanism (TAGSAM) – from its
folded storage position. The spacecraft’s two solar panels then move into a
“Y-wing” configuration over the spacecraft’s body, which positions them safely
up and away from the asteroid’s surface during touch down. This configuration
also places the spacecraft’s center of gravity directly over the TAGSAM
collector head, which is the only part of the spacecraft that will contact
Bennu’s surface.
Finding a safe sample collection
site on Bennu’s rocky landscape was a challenge. During the sampling event, the spacecraft, which
is the size of a large van, will attempt to touch down in an area that is only
the size of a few parking spaces, and just a few steps away from enormous
boulders.
The spacecraft will only make
contact with Bennu for a matter of seconds - just long enough to blow nitrogen
gas onto the surface to roil up dust and small pebbles, which will then be
captured for a return to Earth.
We need to conduct a few tests
before we can confirm we collected a large enough sample (about 2 oz). First,
OSIRIS-REx will take images of the collector head to see if it contains rocks
and dust. Second, the spacecraft will spin with the TAGSAM extended to determine the
mass of collected material. If these measures show a successful collection, we
will stow the sample for return to Earth. If sufficient sample has not been
collected, the spacecraft has onboard nitrogen charges for two more attempts. The
next TAG attempt would be made no earlier than January 2021.
Despite the many challenges, the OSIRIS-REx team is ready.
They’ve practiced and prepared for this moment.
Join in with #ToBennuAndBack and tune in on October 20th.
Learn more about the OSIRIS-REx countdown to TAG HERE.
Applying Wallpaper: 1. Click on the screen resolution you would like to use. 2. Right-click on the image (control-click on a Mac) and select the option ‘Set the Background’ or 'Set as Wallpaper’ (or similar).
1. The Fault in Our Mars
This image from our Mars Reconnaissance Orbiter (MRO) of northern Meridiani Planum shows faults that have disrupted layered deposits. Some of the faults produced a clean break along the layers, displacing and offsetting individual beds.
Our Juno spacecraft captured this image when the spacecraft was only 11,747 miles (18,906 kilometers) from the tops of Jupiter’s clouds – that’s roughly as far as the distance between New York City and Perth, Australia. The color-enhanced image, which captures a cloud system in Jupiter’s northern hemisphere, was taken on Oct. 24, 2017, when Juno was at a latitude of 57.57 degrees (nearly three-fifths of the way from Jupiter’s equator to its north pole) and performing its ninth close flyby of the gas giant planet.
After more than 13 years at Saturn, and with its fate sealed, our Cassini spacecraft bid farewell to the Saturnian system by firing the shutters of its wide-angle camera and capturing this last, full mosaic of Saturn and its rings two days before the spacecraft’s dramatic plunge into the planet’s atmosphere on Sept. 15, 2017.
Saturn’s moon Enceladus drifts before the rings, which glow brightly in the sunlight. Beneath its icy exterior shell, Enceladus hides a global ocean of liquid water. Just visible at the moon’s south pole (at bottom here) is the plume of water ice particles and other material that constantly spews from that ocean via fractures in the ice. The bright speck to the right of Enceladus is a distant star. This image was taken in visible light with the Cassini spacecraft narrow-angle camera on Nov. 6, 2011.
Our Solar Dynamics Observatory came across an oddity this week that the spacecraft has rarely observed before: a dark filament encircling an active region (Oct. 29-31, 2017). Solar filaments are clouds of charged particles that float above the Sun, tethered to it by magnetic forces. They are usually elongated and uneven strands. Only a handful of times before have we seen one shaped like a circle. (The black area to the left of the brighter active region is a coronal hole, a magnetically open region of the Sun).
See Jupiter’s southern hemisphere in beautiful detail in this image taken by our Juno spacecraft. The color-enhanced view captures one of the white ovals in the “String of Pearls,” one of eight massive rotating storms at 40 degrees south latitude on the gas giant planet. The image was taken on Oct. 24, 2017, as Juno performed its ninth close flyby of Jupiter. At the time the image was taken, the spacecraft was 20,577 miles (33,115 kilometers) from the tops of the clouds of the planet.
Our Cassini spacecraft obtained this panoramic view of Saturn’s rings on Sept. 9, 2017, just minutes after it passed through the ring plane. The view looks upward at the southern face of the rings from a vantage point above Saturn’s southern hemisphere.
This sequence of images from our Solar Dynamics Observatory shows the Sun from its surface to its upper atmosphere all taken at about the same time (Oct. 27, 2017). The first shows the surface of the sun in filtered white light; the other seven images were taken in different wavelengths of extreme ultraviolet light. Note that each wavelength reveals somewhat different features. They are shown in order of temperature, from the first one at about 11,000 degrees Fahrenheit (6,000 degrees Celsius) on the surface, out to about 10 million degrees in the upper atmosphere. Yes, the sun’s outer atmosphere is much, much hotter than the surface. Scientists are getting closer to solving the processes that generate this phenomenon.
This orthographic projection shows dwarf planet Ceres as seen by our Dawn spacecraft. The projection is centered on Occator Crater, home to the brightest area on Ceres. Occator is centered at 20 degrees north latitude, 239 degrees east longitude.
This image from our Mars Reconnaissance Orbiter shows a small portion of the floor of Coprates Chasma, a large trough within the Valles Marineris system of canyons. Although the exact sequence of events that formed Coprates Chasma is unknown, the ripples, mesas, and craters visible throughout the terrain point to a complex history involving multiple mechanisms of erosion and deposition. The main trough of Coprates Chasma ranges from 37 miles (60 kilometers) to 62 miles (100 kilometers) in width.
See history in the making on September 22! That’s the day OSIRIS-REx, the first U.S. mission to carry samples from an asteroid back to Earth, will make a close approach to Earth as it uses our planet’s gravity to slingshot itself toward the asteroid Bennu.
Over the course of several days, observatories and amateur astronomers will be able to spot the spacecraft. Below, 10 things to know about this incredible mission that will bring us the largest sample returned from space since the Apollo era.
1. Big Deal
OSIRIS-REx seeks answers to the questions that are central to the human experience: Where did we come from? What is our destiny? Asteroids, the leftover debris from the solar system formation process, can help us answer these questions and teach us about the history of the Sun and planets.
2. That’s a Long Acronym
Yup. OSIRIS-REx stands for the Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer spacecraft. The gist: It will rendezvous with, study, and return a sample of the asteroid Bennu to Earth.
3. Lots of Instruments, Too
While all the acronyms for each instrument may be alphabet soup, each has a job/role to perform in order to complete the mission. Explore what each one will do in this interactive webpage.
4. Nice to Meet You, Bennu
Scientists chose Bennu as the mission target because of its composition, size, and proximity to Earth. Bennu is a rare B-type asteroid (primitive and carbon-rich), which is expected to have organic compounds and water-bearing minerals like clays.
5. Hard Knock Life
Bennu had a tough life in a rough neighborhood: the early solar system. It’s an asteroid the size of a small mountain born from the rubble of a violent collision, hurled through space for millions of years and dismembered by the gravity of planets—but that’s exactly what makes it a fascinating destination.
6. High Fives All Around
In 2018, OSIRIS-REx will approach Bennu and begin an intricate dance with the asteroid, mapping and studying Bennu in preparation for sample collection. In July 2020, the spacecraft will perform a daring maneuver in which its 11-foot arm will reach out for a five-second “high-five” to stir up surface material, collecting at least 2 ounces (60 grams) of small rocks and dust into a sample return capsule.
7. Home Sweet Home
OSIRIS-REx launched on September 8, 2016 from Cape Canaveral, Florida on an Atlas V rocket. In March 2021, the window for departure from the asteroid will open and OSIRIS-REx will begin its return journey to Earth, arriving two-and-a-half years later in September 2023.
8. Precious Cargo
The sample will head to Earth inside of a return capsule with a heat shield and parachutes that will separate from the spacecraft once it enters the Earth’s atmosphere. The capsule containing the sample will be collected at the Utah Test and Training Range. Once it arrives, it will be transported to NASA’s Johnson Space Center in Houston for examination. For two years after the sample return (from late 2023-2025) the science team will catalog the sample and conduct the analysis needed to meet the mission science goals. NASA will preserve at least 75% of the sample at NASA’s Johnson Space Flight Center in Houston for further research by scientists worldwide, including future generations of scientists.
9. Knowledge Is Power
Analyzing the sample will help scientists understand the early solar system, as well as the hazards and resources of near-Earth space. Asteroids are remnants of the building blocks that formed the planets and enabled life. Those like Bennu contain natural resources such as water, organics and metals. Future space exploration and economic development may rely on asteroids for these materials.
10. Hitch a Ride
Journey with OSIRIS-REx as it launches, cruises, and arrives to Bennu in this interactive timeline.
One year ago, on Sept. 15, 2017, NASA’s Cassini spacecraft ended
its epic exploration of Saturn with a planned dive into the planet’s
atmosphere–sending back new science to the last second. The spacecraft is
gone, but the science continues. Here are 10 reasons why Cassini mattered…
1.
Game Changers
Cassini and ESA (European Space Agency)’s Huygens probe expanded our understanding of the
kinds of worlds where life might exist.
2. A (Little) Like Home
At Saturn’s largest moon,
Titan, Cassini and Huygens showed us one of the most Earth-like worlds we’ve
ever encountered, with weather, climate and geology that provide new ways to
understand our home planet.
3. A Time Machine (In a Sense)
Cassini gave us a portal to see the physical processes that likely
shaped the development of our solar system, as well as planetary systems around
other stars.
4. The Long Run
The length of Cassini’s mission enabled us to observe weather and
seasonal changes over nearly half of a Saturn year, improving our understanding
of similar processes at Earth, and potentially those at planets around other
stars.
5. Big Science in Small Places
Cassini revealed Saturn’s moons to be unique worlds with their own
stories to tell.
6. Ringscape
Cassini showed us the complexity of Saturn’s rings and the
dramatic processes operating within them.
7. Pure Exploration
Some of Cassini’s best discoveries were serendipitous. What
Cassini found at Saturn prompted scientists to rethink their understanding of
the solar system.
8. The Right Tools for the Job
Cassini represented a staggering achievement of human and
technical complexity, finding innovative ways to use the spacecraft and its
instruments, and paving the way for future missions to explore our solar
system.
9. Jewel of the Solar System
Cassini revealed the beauty of Saturn, its rings and moons,
inspiring our sense of wonder and enriching our sense of place in the cosmos.
10. Much Still to Teach Us
The data returned by Cassini during its 13 years at Saturn will
continue to be studied for decades, and many new discoveries are undoubtedly
waiting to be revealed. To keep pace with what’s to come, we’ve created a new
home for the mission–and its spectacular images–at https://solarsystem.nasa.gov/cassini.
Make
sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.
The first confirmation of a planet orbiting a star outside our solar system happened in 1995. We now know that these worlds – also known as exoplanets – are abundant. So far, we’ve confirmed more than 4000. Even though these planets are far, far away, we can still study them using ground-based and space-based telescopes.
Our upcoming James Webb Space Telescope will study the atmospheres of the worlds in our solar system and those of exoplanets far beyond. Could any of these places support life? What Webb finds out about the chemical elements in these exoplanet atmospheres might help us learn the answer.
How do we know what’s in the atmosphere of an exoplanet?
Most known exoplanets have been discovered because they partially block the light of their suns. This celestial photo-bombing is called a transit.
During a transit, some of the star’s light travels through the planet’s atmosphere and gets absorbed.
The light that survives carries information about the planet across light-years of space, where it reaches our telescopes.
(However, the planet is VERY small relative to the star, and VERY far away, so it is still very difficult to detect, which is why we need a BIG telescope to be sure to capture this tiny bit of light.)
So how do we use a telescope to read light?
Stars emit light at many wavelengths. Like a prism making a rainbow, we can separate light into its separate wavelengths. This is called a spectrum. Learn more about how telescopes break down light here.
Visible light appears to our eyes as the colors of the rainbow, but beyond visible light there are many wavelengths we cannot see.
Now back to the transiting planet…
As light is traveling through the planet’s atmosphere, some wavelengths get absorbed.
Which wavelengths get absorbed depends on which molecules are in the planet’s atmosphere. For example, carbon monoxide molecules will capture different wavelengths than water vapor molecules.
So, when we look at that planet in front of the star, some of the wavelengths of the starlight will be missing, depending on which molecules are in the atmosphere of the planet.
Learning about the atmospheres of other worlds is how we identify those that could potentially support life…
…bringing us another step closer to answering one of humanity’s oldest questions: Are we alone?
Watch the full video where this method of hunting for distant planets is explained:
To learn more about NASA’s James Webb Space Telescope, visit the website, or follow the mission on Facebook, Twitter and Instagram.
Text and graphics credit Space Telescope Science Institute
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.
LaRue Burbank, mathematician and computer, is just one of the many women who were instrumental to NASA missions.
4 Little Known Women Who Made Huge Contributions to NASA
Women have always played a significant role at NASA and its predecessor NACA, although for much of the agency’s history, they received neither the praise nor recognition that their contributions deserved. To celebrate Women’s History Month – and properly highlight some of the little-known women-led accomplishments of NASA’s early history – our archivists gathered the stories of four women whose work was critical to NASA’s success and paved the way for future generations.