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Planets

Pluto and its moon Charon

New Research

New Definition Would Make the Moon and Pluto Planets

A suggested update to the International Astronomical Union criteria would add over 100 planets to the solar system

Artists rendering of the suspected Planet 9

Trending Today

NASA Wants the Public to Log In to Help Find Planet 9

Citizen scientists can examine photos to help discover a new planet, which recent evidence suggests is hiding at the edge of the solar system

What thorny ethical issues await us once we make it to Mars? A composite image of the red planet, composed by processing about 1000 Viking Orbiter red- and violet-filter images have been to provide global color coverage at a scale of 1 km/pixel.

Think Big

When Humans Begin Colonizing Other Planets, Who Should Be in Charge?

The biggest threat humans pose to other worlds is what we don’t know—or what we think we know, but don’t

The seven Earth-sized planets orbiting the dwarf star TRAPPIST-1.

Think Big

Scientists Spot Seven Earth-Sized Planets Orbiting a Nearby Star

This newly discovered solar system presents the best opportunity yet to study potentially habitable worlds, NASA scientists report

British statesman and author Winston Churchill reads correspondence at his desk in 1933.

Think Big

“Are We Alone in the Universe?” Winston Churchill’s Lost Extraterrestrial Essay Says No

The famed British statesman approached the question of alien life with a scientist’s mind

This image shows a region in Saturn's outer B ring. NASA's Cassini spacecraft viewed this area at a level of detail twice as high as it had ever been observed before. And from this view, it is clear that there are still finer details to uncover. Researchers have yet to determine what generated the rich structure seen in this view, but they hope detailed images like this will help them unravel the mystery.

Cool Finds

NASA Releases Spectacular New Snapshots of Saturn’s Rings

Millions of moonlets appear to be tucked inside the debris that famously circles the planet

The bow-shaped wave on Venus

New Research

Scientists Spot Massive Wave in Venus’ Atmosphere

The 6,200-mile long bow-shaped wrinkle may have been caused by gravity waves

Caption: Six pairs of hand and footprints were discovered in 1998, including two that are small enough to have belonged to children.

New Research

Footprints Found at Ancient Hot Springs Could Represent Earliest Settlement of Tibetan Plateau

New age measurements of the footprints help pinpoint when humans first settled the highest region on Earth

Ask Smithsonian

Why Were Electric Cars Once Advertised as ‘Ladies’ Cars’?

Your questions answered by our experts

New asteroids are detected every day surrounding Earth, most of which are harmless.

Think Big

Sure, Earth Could Get Hit by a Deadly Asteroid—But There’s an Upside

Con: Devastating outer space impacts. Pro: Global unity!

A compressed view of the entire visible sky from the Pan-STARRS1 Observatory

New Research

Massive Survey Catalogues the Night Sky

Over four years, the Pan-STARRS telescope collected 2 petabytes of photos of the night sky, creating the most complete astronomical atlas yet

This collage of images from NASA's Cassini spacecraft shows Saturn's northern hemisphere and rings as viewed with four different spectral filters. Each filter is sensitive to different wavelengths of light and reveals clouds and hazes at different altitudes.

New Research

Check Out New Pictures of Saturn From Cassini’s Latest Orbit

New images of the ringed planet herald the spacecraft’s demise

Two trainees work on repairs.

How to Experience a Mission to Mars (If You Still Want to Come Back)

Space Camp for adults? It’s definitely a thing

Cassini crosses Saturn's F ring once on each of its 20 Ring-Grazing Orbits, shown here in tan and lasting from late November 2016 to April 2017. Blue represents the extended solstice mission orbits, which precede the ring-grazing phase.

Trending Today

In Its Final Hurrah, Cassini Will Swoop Past Saturn’s Rings

The craft will take one last look at the ringed planet before diving into its depths

Mercury's Great Valley is the dark blue stripe across the center of the image.

Life in the Cosmos

Mercury’s Newly-Discovered “Great Valley” Puts Earth’s Grand Canyon to Shame

The vast scar across the tiny planet is remarkable in itself—but it also reveals that Mercury may still be tectonically active

Sputnik Planitia is a 325,000-square-mile, ice-covered basin on Pluto.

How the Pull of an Icy “Heart” Sent Pluto’s Poles Wandering

Using New Horizons data, scientists determine that the erstwhile planet has a more dynamic past than we thought

ALMA Reveals Planets Born Earlier Than We Thought

In 2014, astronomer David Wilmer aimed the ALMA Array at a young star 450 light years away

Two natural color images from NASA's Cassini spacecraft show the changing appearance of Saturn's north polar region between 2012 and 2016.

New Research

The Swirling Storm Above Saturn’s North Pole Changed Colors

The years-long shift may be a sign of changing seasons

Six Places on Earth That Scientists Say Look Like Other Planets

The eerie resemblance these locales have to Mars and beyond has attracted researchers for years

New Research

Uranus May Have Been Hiding Two Moons

Researchers spotted ripples in the planet’s rings, which may be tracks left from two tiny moons

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