Slanted shot shows black space over the gray, cratered horizon of Mercury

Solar System

Do Glaciers on Mercury Suggest Such a Planet Could Be Habitable?

Salt glaciers on Mercury suggest conditions friendly to life — but not life itself — might once have existed on the innermost planet.

Illustration of BepiColumbo in front of Mercury

Solar System

BepiColombo First Picture of Mercury (Updated)

BepiColombo is set to make the first of several flybys past Mercury on Friday, October 1st.

Chaotic terrain on Mercury

Solar System

Why Have Parts of Mercury's Landscape "Deflated"?

A type of landscape on Mercury known as “chaotic terrain” might have released materials stored underground for eons.

Transit of Mercury 2019 (composite)

Celestial News & Events

Capturing the Transit of Mercury

Though clouds blocked the sky for many yesterday, those with a clear view had the chance to see tiny Mercury cross the face of the Sun.

Explore the Night with Bob King

Don't Miss Monday's Rare Transit of Mercury

On Monday, November 11th, Mercury will pass directly in front of the Sun and look a tiny black dot silhouetted against the brilliant solar disk. The event, called a transit, occurs approximately 13 times a century.

Transit comparison

Celestial News & Events

Citizen Science with the Transit of Mercury

If you're planning on watching the November 11th transit of Mercury, try kicking it up a notch — watch with a friend and calculate the distance between Earth and the Sun!

Explore the Night with Bob King

Perseid Prospects, Mornings with Mercury and the Lunar X

With the Perseid shower, a great morning apparition of Mercury, and a chance to see craters scratch out an X on the moon, skywatchers have a busy week ahead! 

Explore the Night with Bob King

A Zodiac Ramble . . . with a Few Fun Detours

Take a trip along the ecliptic from dusk till dawn to check out the sights along this well-traveled highway — the zodiacal light, Mercury, and the gegenschein, plus scenic detours to a comet and asteroid.

Celestial News & Events

Venus Occults a Star and Mercury Joins Jupiter on the Winter Solstice

Bring in winter with a bang with a beautiful, close conjunction and a rare planet-star occultation.

Image of BepiColumbo launch

Space Missions

Mission to Mercury Launches

The BepiColombo spacecraft, Europe's first mission to Mercury, rocketed away from Earth to begin its seven-year trek to the innermost planet.

Near and Far Planets Draw Close

Explore the Night with Bob King

See Mercury First, Then Have Breakfast

Late sunrises make it easy to follow the parade of planets at dawn, including a nice apparition of Mercury this week with three successive lunar conjunctions.

Feather of Dusty Light

Explore the Night with Bob King

Mercury Punctuates The False Dawn

Early risers get a triple treat this week and next: a ravishing dawn Moon, an excellent apparition of Mercury, and a hint of Halloween in the ghostly zodiacal light.

Mercury transit 2016 in H-alpha light

Celestial News & Events

Mercury's Slow Glide Across the Sun

May 9th's transit of Mercury is now history. Countless amateurs — and professionals — watched as the innermost planet had its day in the Sun. It's sometimes the curse of being involved in astronomical outreach that I miss all the action during an important celestial event. For example, I never…

Transit of Mercury composite

Celestial News & Events

Mercury Transit: Everything You Need to Know

The littlest planet will cross the enormous Sun for viewers in most of the world.

Mercury on April 15th

Celestial News & Events

How to Spot Mercury in the Evening Sky

If you've never seen the fleet-footed planet Mercury, now is a great time to look for it in the evening sky after sunset.