On August 25, 1989, a NASA spacecraft made its fourth and final planetary encounter. What it revealed 25 years ago about the Neptunian system is still amazing and still profound.
Late summer offers the Teapot of Sagittarius and the nearby arc of the Scorpion's Tail in the evening, the Perseid meteor shower, and a spectacular pairing of Venus and Jupiter before dawn.
It's not a showstopper, but right now Comet Jacques (C/2014 E2) is poised for telescopic viewing in the hours before dawn.
How did the the innermost planet get its huge iron core? New computer modeling suggests that Mercury is a lucky survivor of chaotic primordial smashups.
Researchers have announced interesting news concerning the Moon, especially about how and when it formed, and why the "Man in the Moon" constantly stares at us whenever the lunar disk is fully lit.
Although its scientific work for NASA ended in the early 1980s, the International Sun-Earth Explorer never quite died — and this week it was revived by a team of volunteers intent on letting it continue exploring interplanetary space.
Sky & Telescope's audio sky tour makes it easy to discover the night sky. During July, the Moon makes very close brushes with Mars and Saturn.
A small asteroid slammed into the Martian surface sometime between March 27 and 28, 2012, creating a crater swarm in the ground. The largest pit is 159 feet across.
For anyone north of the equator, days are longest and nights shortest during June. But you can still get an eyeful of celestial sights, starting with a parade of Jupiter, Mars, and Saturn in the evening sky.
Dynamicists had predicted that Comet 209P/LINEAR would create an active meteor display in the early morning of May 24th. But reports from observers across the U.S. and Canada suggest that the Camelopardalid meteor shower was weak at best.
The dim, obscure periodic comet 209P/LINEAR is about to pass close by Earth — and bring with it a trail of debris that could make for an exciting meteor shower during the predawn hours of Saturday May 24th for North America.
Now in its 15th year, the Edgar Wilson Award recognizes comet discoveries made by amateur observers. The 2013 awards honor seven dedicated individuals who scan the skies.
This celebration of "bringing astronomy to the people" features events across the nation and around the world.
The first and only annular solar eclipse of 2014 has a path that just clips Antarctica, at a location so remote that no one on Earth will get to see the event. Update: Partial phases of April 29th's solar eclipse were widely seen across the southern part of Australia. See the bottom of this...
This month you have a chance to spot four planets in the evening sky at once: Mercury, Mars, Jupiter, and Saturn. As a bonus, you might be treated to a spectacular display of meteors on the morning of May 24th.
Astronomers don't know why Jupiter's iconic Great Red Spot has been gradually shrinking since the 1800s — or why the downsizing has accelerated during the past two years. Update: On May 15th, NASA released newly taken images of the Great Red Spot (at bottom below) to show its declining size since 1995. Thanks to...
In 2002, high-school student Jennifer Barlow had a simple idea: let's take some time to appreciate the beauty of the cosmos and consider ways to reduce the spread of light pollution. Here's how you can join the celebration! Have you ever stepped outside to take in a view of the starry sky overhead —...
Here's a quick guide to the essential features that you should look for when buying your first telescope.
It's a great month, celestially speaking: the brilliant stars of winter crowd in the southwest at nightfall, Jupiter is joined by Mars, and the first total lunar eclipse in 2½ years occurs at mid-month.
There was widespread hope that thousands of skywatchers would see the bright star Regulus briefly occulted by an asteroid early on March 20th. In the end, likely <u>no one</u> saw it. Here's why.
Astronomers have kicked around the idea of a distant "Planet X" for decades. But the recent discovery of 2012 VP<sub>113</sub>, located in an orbital "no man's land" roughly twice as far away as Pluto, has stoked the possibility that it really exists.
Now that they've seen all of the innermost planet up close, geologists realize that Mercury's crust buckled and fractured as the planet cooled and shrank far more than previously measured.
A team of European researchers believe that a big, fresh-looking crater on Mars is the likely launch pad for many of the Martian meteorites found on Earth.
A big-budget television series about astronomy — a much-anticipated sequel to the iconic 1980 original — debuts this weekend in 174 countries and 47 languages.
A stunning array awaits you overhead once the Sun sets. Brilliant Sirius, along with Procyon, Betelgeuse, and even-brighter Jupiter, form a giant diamond in the evening sky.