New Horizons at Io
4.04.2007

Spewed from a volcano, a complex plume rises over 300 kilometers above the horizon of Jupiter's moon Io in this image from cameras onboard the New Horizons spacecraft. The volcano, Tvashtar, is marked by the bright glow (about 1 o'clock) at the moon's edge, beyond the terminator or night/day shadow line.

Meteors and Aurorae over Iceland
7.08.2013

What's going on behind that volcano? Quite a bit. First of all, the volcano itself, named Kirkjufell, is quite old and located in western Iceland near the town of GrundarfjЖrПur. In front...

Keck: The Largest Optical Telescope
15.07.1996

In buildings eight stories tall rest mirrors ten meters across that are slowly allowing humanity to map the universe. Alone, each is the world's largest optical telescope: Keck. Together, the twin Keck telescopes have the resolving power of a single telescope 90-meter in diameter, able to discern sources just milliarcseconds apart.

Possible Mud Volcanoes on Mars
30.03.2009

Is this a mud volcano on Mars? If so, could it be dredging up martian microbes? This strange possibility has been suggested recently and seems to fit several recent observations of Mars. First of all, hills like this seem to better resemble mud volcanoes on Earth than lava volcanoes and impact craters on Mars.

Galileo's First Color Image of Io
19.07.1996

Above is the first color image of Jupiter's volcanic moon Io released by the Galileo Project. (Io sounds like "eye-oh".) The image was made on June 25 when the Galileo spacecraft approached within 1.4 million miles.

Wright Mons in Color
15.01.2016

Informally named Wright Mons, a broad mountain about 150 kilometers across and 4 kilometers high with a wide, deep summit depression is featured in this inset image captured during the New Horizons flyby of Pluto in July 2015.

The Milky Way Over Mauna Kea
27.01.2009

Have you ever seen the band of our Milky Way Galaxy? In a clear sky from a dark location at the right time, a faint band of light becomes visible across the sky. Soon after your eyes become dark adapted, you might spot the band for the first time. It may then become obvious.

Arachnoids on Venus
20.01.1998

Arachnoids are large structures of unknown origin that have been found only on the surface of Venus. Arachnoids get their name from their resemblance to spider-webs. They appear as concentric ovals surrounded by a complex network of fractures, and can span 200 kilometers.

Venus, Moon, and the Smoking Mountain
15.09.2023

Venus has returned as a brilliant morning star. From a window seat on a flight to Mexico City, the bright celestial beacon was captured just before sunrise in this astronomical snapshot, taken on September 12. Venus, at the upper right, shared the early predawn skies with an old crescent Moon.

Tungurahua Erupts
2.04.2012

Volcano Tungurahua sometimes erupts spectacularly. Pictured above, molten rock so hot it glows visibly pours down the sides of the 5,000-meter high Tungurahua, while a cloud of dark ash is seen being ejected toward the left. Wispy white clouds flow around the lava-lit peak, while a star-lit sky shines in the distance.