A study of ten narwhal tusks reveals how the animals are responding to a swiftly changing Arctic.

New Research

Study of Narwhal Tusks Reveals a Swiftly Changing Arctic

Chemical analysis of ten tusks shows shifting diets and increasing levels of mercury as climate change warms the polar region

The Maya city of Tikal thrived for hundreds of years but was  abandoned in the ninth century A.D.

New Research

Why Did the Maya Abandon the Ancient City of Tikal?

New research suggests mercury and toxic algae poisoned the settlement's reservoirs

Watch Colorful Sunsets on Distant Planets in This NASA Simulation

New models from a NASA scientist show what the sun’s setting might look like on Venus, Uranus and Mars

An enhanced-color image of Mercury taken by the MESSENGER spacecraft in 2012 as part of a mission to map the geologic features of the planet.

Spacecraft Launching This Week Will Explore the Mysteries of Mercury

The BepiColombo mission will study the geology and magnetism of the smallest planet to search for clues of our solar system's beginnings

Now held in the collections of the Smithsonian's National Air and Space Museum are a 35 mm camera (left) and a digital camera. Each was used by John Glenn on his two journeys into outer space.

How John Glenn’s Encore Space Flight Lifted U.S. Spirits

Two cameras tell the tale of the first American to orbit Earth and his return to space 36 years later

Four of the seven newly named Mercury's faculae lie in the Caloris basin, shown here.

Sci-Fi and Snakes Rule in New Official Names for Features on Pluto's Largest Moon and Mercury

Stanley Kubrick and Octavia Butler are among the figures honored

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

Mercury’s northern volcanic plains shown in enhanced color to emphasize rocks types. The bottom left portion of the image displays large wrinkle ridges, formed during lava cooling. Near the top of the image, a bright orange region shows the location of a volcanic vent.

New Research

See Mercury's Landscape in Stunning Detail

A new map of the planet's surface captures the depths of craters and the peaks of volcanic mountains

An illustration of the path Mercury will take across the sun on  May 9.

Cool Finds

For The First Time in a Decade, Watch Mercury Cross the Sun's Face

Next week's transit of Mercury is one of the major astronomical events of the year

Trending Today

The Orionid Meteor Shower and Rare Planetary “Dance” Make This a Lucky Week for Stargazers

Here’s what the night sky has to offer this week

Mercury as seen by Messenger

Trending Today

Today The Messenger Spacecraft Will Crash Into Mercury

After years of exciting observations and stunning pictures of Mercury, the spacecraft has run out of fuel

Mercury's Munch crater, as viewed by the MESSENGER probe.

Trending Today

The Messenger Probe Will Soon Crash Into Mercury

As NASA's probe runs out of propellant, it will crash into the planet’s surface at 8,750 MPH

New Research

Mercury Was Once Bigger, Then It Shrank

As the planet cooled, it contracted and shut off the surface lava flows about 3.8 billion years ago

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