Mercury in true color (left) and enhanced color (right).
Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

June 10, 2025

Mercury watchers will have several chances to view this elusive planet over the next two weeks. Since Mercury is the closest planet to the sun, there is a small window in which it is visible. Use extreme caution to avoid looking directly at the Sun when gazing low in the West South-west at dusk, around 9:00–9:15 p.m. The smallest planet in the solar system will be at its brightest of the year near June 12 but will rise higher in the sky towards June 29–30.

This small rocky planet that zips around the sun in only 88 days has a pocked surface similar to our moon. However, Mercury’s surface is far less reflective. Only about two-thirds as much light beams back.

The BepiColumbo spacecraft, joint mission of ESA (European Space Agency) and JAXA (Japan Aerospace Exploration Agency, imaged volcanic vents and enormous craters on its most recent Mercury fly-by, January 2025. It was startling to discover water ice close to the sun, hidden deep in permanently shadowed craters. When BepiColumbo orbits around the planet in 2026, two main orbiters will deploy around the pole regions to further explore some of the solar system’s coldest places.

As Mercury’s enormous iron core continues to cool, the tiny planet keeps shrinking. Its single continental plate wrinkled into a stunning “Great Valley,” an area far wider and deeper than Earth’s Grand Canyon.

Are you as fascinated by the night sky as we are?

Join us for SkyWatch: Carnegie Science Center’s monthly opportunity to catch a glimpse of the stars with professional telescopes. Get a great view of the Pittsburgh skyline as you stargaze with other space enthusiasts. Plus, watch a feature show at the Buhl Planetarium and participate in fun, astronomy-themed activities.