vania-janet/multiturn-rag-retrieval-data huggingface dataset:
Overview | What is an Exoplanet? – Exoplanet Exploration: Planets Beyond our Solar System
One of the Roman Space Telescope's objectives will be looking for clues about dark energy—the mysterious force that is accelerating the expansion of the universe. Credit: NASA's Goddard Space Flight Center

Most exoplanets are found through indirect methods: measuring the dimming of a star that happens to have a planet pass in front of it, called the transit method, or monitoring the spectrum of a star for the tell-tale signs of a planet pulling on its star and causing its light to subtly Doppler shift. Space telescopes have found thousands of planets by observing “transits,” the slight dimming of light from a star when its tiny planet passes between it and our telescopes. Other detection methods include gravitational lensing, the so-called “wobble method.” 

Credits: NASA/W. Stenzel

But when multiple methods are used together, we can learn the vital statistics of whole planetary systems – without ever directly imaging the planets themselves. The best example so far is the TRAPPIST-1 system about 40 light-years away, where seven roughly Earth-sized planets orbit a small, red star.
The TRAPPIST-1 planets have been examined with ground and space telescopes. The space-based studies revealed not only their diameters, but the subtle gravitational influence these seven closely packed planets have upon each other; from this, scientists determined each planet’s mass.
So now we know their masses and their diameters. We also know how much of the energy radiated by their star strikes these planets’ surfaces, allowing scientists to estimate their temperatures. We can even make reasonable estimates of the light level, and guess at the color of the sky, if you were standing on one of them. And while much remains unknown about these seven worlds, including whether they possess atmospheres or oceans, ice sheets or glaciers, it’s become the best-known solar system apart from our own.

Planet Types

Exoplanets come in a wide variety of sizes, from gas giants larger than Jupiter to small, rocky planets about as big around as Earth or Mars. They can be hot enough to boil metal or locked in deep freeze.
In Depth - NASA Science
At NASA, we're surveying and studying exoplanets to learn all about their weirdness, their variety, and all the fascinating things they can tell us about how planets form and develop.NASA/JPL-CaltechMost of the exoplanets discovered so far are in a relatively small region of our galaxy, the Milky Way. ("Small" meaning within thousands of light-years of our solar system; one light-year equals 5.88 trillion miles, or 9.46 trillion kilometers.) That is as far as current telescopes have been able to probe. We know from NASA’s Kepler Space Telescope that there are more planets than stars in the galaxy.Although exoplanets are far – even the closest known exoplanet to Earth, Proxima Centauri b, is still about 4 light-years away – scientists have discovered creative ways to spot these seemingly tiny objects.Unable to render the provided sourceAt only four light-years away, Proxima b is our closest known exoplanet neighbor.How Do We Find Exoplanets?There are five methods scientists commonly use to discover exoplanets.The two main techniques are the transit and radial velocity methods.When a planet passes directly between an observer and the star it orbits, it blocks some of that starlight. For a brief period of time, that star’s light actually gets dimmer. It's a tiny change, but it's enough to clue astronomers in to the presence of an exoplanet around a distant star. This is known as the transit method.Unable to render the provided sourceOrbiting planets cause stars to wobble in space, changing the color of light astronomers see when observing a star. Stars are affected by the gravitational tug of their orbiting planets and, when observed through a telescope, this affects the star's light spectrum. If the star moves in the direction of the observer it will appear to be shifted toward blue. If it is moving away from the observer, it will shift toward the red. Observing this is known as the radial velocity method.NASA’s Exoplanet Space TelescopesThousands of exoplanets have been discovered and confirmed orbiting other stars.
Juno - NASA Science
The extension permitted encounters with three of Jupiter's intriguing Galilean moons – Ganymede, Europa, and Io.NASA/JPL-Caltech/SwRIScientific Discoveries and ResultsThe signature bands of multicolored clouds we see encircling Jupiter, called belts (the dark orange stripes) and zones (the light areas, in shades of gray), penetrate deep into the atmosphere. But how far? One of the most fundamental questions about the giant planet, scientists have debated that for decades. By measuring Jupiter’s gravity field, Juno discovered that the belts and zones – which are alternating east- and west-flowing jet streams – extend about 1,900 miles (3,000 kilometers) below the cloud tops.  Scientists long thought Jupiter had a small, solid core surrounded by all its hydrogen and helium. Juno data suggests the core is much larger than expected, yet partially dissolved, with no clear separation from the hydrogen swirling around it, leading researchers to describe the core as dilute, or “fuzzy.”  Under extreme pressure, gases can turn into their liquid form. Inside Jupiter the atmospheric pressure is so great, it compresses hydrogen gas not merely into liquid, but a fluid known as liquid metallic hydrogen. This exaggerated pressure makes the liquid hydrogen act like a metal conducting electricity, and scientists believe it’s the source of Jupiter’s uniquely intense magnetic field. Years of Juno measurements of Jupiter’s magnetic field point to that possibility, at a depth much shallower than expected.   Before Juno arrived, the largest planet in our solar system still had vast areas unexplored, unknown, even unseen. Among other discoveries Juno made possible: JunoCam provided the first clear, close-up pictures of Jupiter’s north pole – a strange, bluish region full of giant storms and strange weather. A central cyclone at the north pole is surrounded by eight more, as if they’re bowing in tribute. These cyclones stretch more than 2,500 miles across (4,000 kilometers). And though their spiral arms smack together as they spin, the storms don’t merge. During a close flyby of the south pole, Juno spotted a new, giant cyclone in the region.
Jupiter - NASA Science
MaterialsRoboticsScience InstrumentsComputingThe Universe ExoplanetsThe Search for Life in the UniverseStarsGalaxiesBlack HolesThe Big BangDark Matter &amp; Dark EnergyThe Solar System The SunMercuryVenusEarthThe MoonMarsJupiterSaturnUranusNeptunePluto &amp; Dwarf PlanetsAsteroids, Comets &amp; MeteorsThe Kuiper BeltThe Oort CloudSkywatchingEspañol CienciaAeronáuticaCiencias TerrestresSistema SolarUniversoScience All NASA ScienceEarth SciencePlanetary ScienceAstrophysics & Space ScienceThe Sun & HeliophysicsBiological & Physical SciencesLunar ScienceCitizen ScienceAstromaterialsAeronautics ResearchHuman Space Travel ResearchExploreSearchSubmitNews & EventsMultimediaNASA+Jupiter OverviewFactsExplorationJupiter MoonsOverviewFactsStoriesResourcesAll PlanetsMercuryVenusEarthMarsJupiterSaturnUranusNeptunePluto & Dwarf Planets Our Solar SystemExplore This SectionJupiter OverviewFactsExplorationJupiter MoonsStoriesResourcesAll PlanetsOur Solar SystemJupiterJupiter is the fifth planet from the Sun, and the largest in the solar system – more than twice as massive as the other planets combined.10 Things About JupiterExplore Jupiter Facts1. The BiggestFor scale, Jupiter's Great Red Spot is about the size of Earth.2. Fifth From the SunJupiter's distance from the Sun is 5.2 times the Earth-Sun distance.3. Short and LongJupiter's day lasts only 10 Earth hours; its year is 12 Earth years.4. Nowhere to LandAs a gas giant, Jupiter has no solid surface. It may have an Earth-sized core.5. Big and LightJupiter's atmosphere is mostly hydrogen and helium.6. Many MoonsAs of July 2023, Jupiter had 95 moons.7. Faint RingsThe rings were spotted in 1979.8. ExplorationSeven robots flew past; two stayed in orbit.9. Ingredients for Life?Jupiter can't support life as we know it.10.
Saturn - NASA Science
It’s surrounded by beautiful rings.10 Things about saturnSaturn FactsSecond LargestNine Earths would almost span Saturn’s diameter.Sixth from the SunSaturn is 9.5 AU from the Sun. Earth = 1.Long YearIt takes 29 Earth years for Saturn to orbit the Sun.No SurfaceThis gas giant world may have a small core.Bring a SpacesuitSaturn's atmosphere is mostly hydrogen and helium.King of the MoonsSaturn has the most: 146.The Nicest RingsEight rings make for a spectacular system.Distant DestinationFour missions visited Saturn; one has orbited.Not Suitable For LifeSaturn can't support life as we know it.Cloud HexagonA powerful jet stream shapes the clouds.Planet Saturn OverviewSaturn is the sixth planet from the Sun and the second largest planet in our solar system. Adorned with a dazzling system of icy rings, Saturn is unique among the planets.It is not the only planet to have rings, but none are as spectacular or as complex as Saturn's. Like fellow gas giant Jupiter, Saturn is a massive ball made mostly of hydrogen and helium.The farthest planet from Earth discovered by the unaided human eye, Saturn has been known since ancient times. The planet is named for the Roman god of agriculture and wealth, who was also the father of Jupiter.Unable to render the provided sourceNASA's Eyes is a real-time visualization of our solar system powered by actual planetary science data.NASA/JPL-CaltechPop CulturePerhaps the most iconic of all the planets in our solar system, Saturn is heavily present in pop culture.It provides a backdrop for numerous science fiction stories, movies, and TV shows, comics, and video games, including the "Cthulhu Mythos," "WALL-E," "2001: A Space Odyssey," and "Star Trek." In Tim Burton's film "Beetlejuice," a dusty, fictional Saturn is populated by giant sandworms.
Overview - NASA Science
They can be hot enough to boil metal or locked in deep freeze. They can orbit their stars so tightly that a “year” lasts only a few days; they can orbit two suns at once. Some exoplanets are sunless rogues, wandering through the galaxy in permanent darkness.When we describe different types of exoplanets – planets outside our solar system – what do we mean by "hot Jupiters," "warm Neptunes," and "super-Earths"? Since we're still surveying and learning about the variety of worlds out there among the stars, it's sometimes helpful to refer to characteristics they share with planets we're familiar with in our own planetary system.NASA/JPL-CaltechA galaxy of stars – and planetsOur galaxy, the Milky Way, is the thick stream of stars that cuts across the sky on the darkest, clearest nights. Its spiraling expanse contains at least 100 billion stars, our Sun among them. And if each of those stars has not just one planet, but, like ours, a whole system of them, then the number of planets in the galaxy is truly astronomical: We’re already heading into the trillions.We humans have been speculating about such possibilities for thousands of years, but ours is the first generation to know, with certainty, that exoplanets are really out there. In fact, way out there. Our nearest neighboring star, Proxima Centauri, was found to possess at least one planet – probably a rocky one. It’s about 4 light-years away – more than 25 trillion miles (40 trillion kilometers). The bulk of exoplanets found so far are hundreds or thousands of light-years away.The bad news: As yet we have no way to reach them, and won’t be leaving footprints on them anytime soon. The good news: We can look in on them, take their temperatures, taste their atmospheres and, perhaps one day soon, detect signs of life that might be hidden in pixels of light captured from these dim, distant worlds.Exoplanet discovery – and mysteryThe first exoplanets were discovered in the early 1990s, but the first exoplanet to burst upon the world stage was 51 Pegasi b, a “hot Jupiter” orbiting a Sun-like star 50 light-years away.
Why does Saturn have rings? | NASA Space Place – NASA Science for Kids
The Cassini spacecraft arrived at Saturn in July 2004. It orbited Saturn for 13 years, studying Saturn, its rings, and its moons much more thoroughly than the earlier spacecraft could.
Cassini also carried a probe, called Huygens (HOY-guns), that parachuted into the atmosphere of Saturn's giant moon Titan. Huygens sent back amazing information and images from this strange world whose surface we have never seen.
Cassini and Huygens made many exciting discoveries. In September 2017, Cassini ended its mission with a planned plunge into Saturn's atmosphere. 

A view of Saturn's rings, as seen by the Cassini spacecraft. Credit: NASA/JPL-Caltech/Space Science Institute

 	article last updated September 22, 2017
 

Big rings… Small rings… Fat rings… Skinny rings…

 This series of photos was taken by the Hubble Space Telescope from 1996 through 2000. You can see how Saturn's rings seem to change, but it is only because our angle of view changes.

If you liked this, you may like:

Make a CD Saturn

What Is a Barycenter?

All About Saturn

	 Games	 

	 Crafts	 

	 Activities	 

	 Videos	 

	 Glossary	 

	 Mystery	 

About Us
Privacy Policy
Image Use
Accessibility

Contact NASA Space Place

 Last Updated: May 6th, 2024 

 

More
Less

By Subject

Space
Sun
Earth
Solar System
People & Technology
Parents & Educators

By Type

Explore
Do
Play

More
Less

Big rings… Small rings… Fat rings… Skinny rings…

 This series of photos was taken by the Hubble Space Telescope from 1996 through 2000. You can see how Saturn's rings seem to change, but it is only because our angle of view changes.
Discovery Alert: The Planet that Shouldn't Be There – Exoplanet Exploration: Planets Beyond our Solar System
What is an exoplanet?

An exoplanet is any planet beyond our solar system.

more

Planet types

Planet types

Explore the planet types: Gas Giant, Neptune-like, Super-Earth and Terrestrial

more

How do we find them?

How do we find them?

Learn how we find and characterize exoplanets.

more

What is a habitable zone?

What is a habitable zone?

A habitable zone is the distance from a star at which liquid water could exist on orbiting planets’ surfaces.

more

The search for life

The search for life

Is life in the cosmos easily begun, and commonplace? Or is it incredibly rare?

more

What is an exoplanet?

An exoplanet is any planet beyond our solar system.

more

Planet types

Explore the planet types: Gas Giant, Neptune-like, Super-Earth and Terrestrial

more

How do we find them?

Learn how we find and characterize exoplanets.

more

What is a habitable zone?

A habitable zone is the distance from a star at which liquid water could exist on orbiting planets’ surfaces.

more

The search for life

Is life in the cosmos easily begun, and commonplace? Or is it incredibly rare?

more

Exoplanet Travel Bureau 

From travel posters to 360-degree surface visualizations, NASA offers guided tours of the most exotic destinations in our galaxy. Visit a lava planet, a world with two suns, and more!

Webb Poster

NASA’s James Webb Space Telescope is a true technological marvel. The largest and most complex space telescope ever built, Webb will be able to gather light that has been traveling for 13.5 billion years, almost since the beginning of the universe. In effect, Webb is a time machine, allowing us to peer at the first galaxies to form after the Big Bang. Because it gathers infrared light, it will see right through the giant clouds of dust that block the view of most other telescopes.
Cassini’s Final View of Home
Cassini captured the image on April 13, 2017, when the spacecraft was 870 million miles (1.4 billion kilometers) from Earth. Although it is too small to be visible, the part of Earth facing Cassini was the southern Atlantic Ocean.
The A Ring and Keeler Gap are visible near the top of the image, with the F Ring below. During this observation, Cassini was looking toward the backlit rings and making a mosaic of multiple images with the Sun blocked by the disk of Saturn. The F Ring appears especially bright in this viewing geometry.
From the orbit of Saturn, Earth and the other inner solar system planets are all close to the Sun and can be captured in such images, although such opportunities have been rare during this mission. The satellite delivered similar images in 2006, when it was 1.45 billion kilometers (898 million miles) from Earth, and 2013 when it was 183 million kilometers (114 million miles) away.
All of these images are reminiscent of the pale blue dot image, which was acquired in 1990 when the Voyager spacecraft was 6.4 billion kilometers (4 billion miles) from Earth. Of that image, astronomer Carl Sagan famously said:
Look again at that dot. That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every “superstar,” every “supreme leader,” every saint and sinner in the history of our species lived there—on a mote of dust suspended in a sunbeam.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency, and the Italian Space Agency. NASA’s Jet Propulsion Laboratory manages the mission and designed, developed, and assembled the Cassini orbiter.
Image courtesy the Cassini Imaging Central Laboratory for Operations.
Cassini-Huygens - NASA Science
This view was acquired at a distance of approximately 870,000 miles (1.4 million kilometers) from Saturn. Image scale is 50 miles (80 kilometers) per pixel.NASA/JPL-Caltech/Space Science InstituteScience at SaturnBefore Cassini, we had only brief glimpses of the discoveries awaiting us at Saturn.Cassini changed all that. It began the first in-depth, up-close study of Saturn and its system of rings and moons in 2004. It became the first spacecraft to orbit Saturn, beginning a mission that yielded troves of new insights over more than a decade. The Saturnian system proved to be rich ground for exploration and discoveries, and Cassini's science findings changed the course of future planetary exploration.Read MoreDramatic plumes, both large and small, spray water ice and vapor from many locations along the famed "tiger stripes" near the south pole of Saturn's moon Enceladus. NASA/JPL/Space Science InstituteCassini's Spectacular EndAfter two decades in space, NASA's Cassini spacecraft ended its remarkable journey of exploration.Having expended almost every bit of the rocket propellant it carried to Saturn, operators deliberately plunged Cassini into the planet to ensure Saturn's moons remain pristine for future exploration—in particular, the ice-covered, ocean-bearing moon Enceladus, but also Titan, with its intriguing pre-biotic chemistry.Read MoreA commemorative retro poster created for Cassini's Grand Finale.NASA/JPL-CaltechBacklit SaturnOn July 19, 2013, in an event celebrated the world over, NASA's Cassini spacecraft slipped into Saturn's shadow and turned to image the planet, seven of its moons, its inner rings -- and, in the background, our home planet, Earth.Learn MoreLessons LearnedBefore the mission ended, Cassini was already a powerful influence on future exploration. In revealing that Enceladus has essentially all the ingredients needed for life, the mission energized a pivot to the exploration of "ocean worlds" that has been sweeping planetary science over the past couple of decades.Lessons learned during Cassini's mission are being applied in planning NASA's Europa Clipper mission, planned for launch in October 2024.
Prague at Night
Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. Caption by Cadan Cummings, Jacobs, JETS Contract at NASA-JSC.

View this area in EO Explorer

Infrastructure new and old glows across the Czech Republic’s capital city.
Image of the Day for July 2, 2023

Instrument:
ISS — Digital Camera

Appears in this Collection:
Earth at Night

Image of the Day
Human Presence

View more Images of the Day:

Jul 1, 2023

Jul 3, 2023

You might also be interested in    (view all)

Subscribe to our newsletters
 

Image

Noumea
The capital city is the economic and tourist hub of New Caledonia.

Image of the Day
Land
Human Presence

Image

One Night in Bangkok
Thailand’s capital and most populous city lights up southeast Asia.

Image of the Day
Human Presence

Image

Buenos Aires at Night
Buenos Aires is one of the larger cities seen by orbiting crews. Twelve million people, almost one third of all Argentines, live in this city, often called the “Paris of the South”.

Image of the Day
Land
Life

Image

Nusantara: A New Capital City in the Forest
The future site of Indonesia’s new capital saw rapid change between 2022 and 2024.

Image of the Day
Land
Life
Human Presence

Subscribe
to our newsletters

Feeds
Contact
About
Image Use Policy
Privacy Policy
Accessibility

 Webmaster Paul Przyborski

 NASA Official Robert Levy

 The Earth Observatory is part of the EOS Project Science Office at NASA Goddard Space
 Flight Center
FAQs • Dublin • CivicEngage
If a property is covered by a Homeowners Association, residents should check to see if the Association will allow fireworks.Safe and Sane Fireworks are NOT to be used at City parks, facilities, schools, businesses, or multi-family complexes (such as apartment, condominium, or townhome neighborhoods). Safe and Sane Firework Usage

▼
History of Dublin	

Show All Answers

1.
Crossroads of the Bay Area

The City of Dublin has long been known as a crossroads of the San Francisco Bay Area.  Dublin is located at the crossroads to two major highways: Interstate 580 and Interstate 680.  However, the significance as a crossroads dates back hundreds of years, even to times when Native American trading trails crossed here.  The significance of crossroads grew over time to include Spanish explorers; early Mexican and mission trails; gold rush travelers; early ranchers and farmers; stagecoaches; freight wagons; and later bicycles, cars, trucks, and motorcycles.  With Dublin at the center, important road connections led north to Martinez and Contra Costa County; south to San Jose and Santa Clara County; east to Stockton and the East Coast; and west to Hayward, Oakland, and San Francisco.  Through the years, Dublin has seen Native American hunters and traders, migrating families looking for new homes, gold seekers, farmers, ranchers, military convoys on the way to war, and many, many cars on their commute. 

2.
The First Settlers

The earliest residents of Dublin were Native Americans.  Archaeological evidence suggests that Native Americans lived here for tens of thousands of years. They are undoubtedly the first residents and the residents who lived here longest. Their beliefs say they were here at the dawn of time. Estimates suggest there were between 200 to 400 Native Americans living in the Amador Valley before the 1700s.  Dublin-area Native American tribes spoke Chochenyo Ohlone and Bay Miwok.  Specifically, the Seunen, Ssouyen, and Pelnen tribes lived in parts of what is now Dublin.  Each tribe had a population varying from two hundred to four hundred people. Villages could be found along local streams or along the large marsh that then stretched from Dublin and Pleasanton.