Light Echoes from V838 Mon
4.12.2011

For reasons unknown, star V838 Mon's outer surface suddenly greatly expanded with the result that it became the brightest star in the entire Milky Way Galaxy in January 2002. Then, just as suddenly, it faded. A stellar flash like this has never been seen before.

An Unusual Venusian Oval
13.02.2012

Why would Venus appear oval? Venus has been seen countless times from the surface of the Earth, and every time the Earth's atmosphere has dispersed its light to some degree. When...

A Transit of Mercury
12.05.2016

On May 9, the diminutive disk of Mercury spent about seven and a half hours crossing in front of the Sun as viewed from the general vicinity of Earth. It was the second of 14 transits of the Solar System's innermost planet in the 21st century.

Apollo 11: Earth, Moon, Spaceship
3.05.2021

After the most famous voyage of modern times, it was time to go home. After proving that humanity has the ability to go beyond the confines of planet Earth, the first humans to walk...

APOD: 2023 June 11 Б The Sun and Its Missing Colors
11.06.2023

Here are all the visible colors of the Sun, produced by passing the Sun's light through a prism-like device. The spectrum was created at the McMath-Pierce Solar Observatory and shows, first off, that although our white-appearing Sun emits light of nearly every color, it appears brightest in yellow-green light.

Sojourner On Mars
7.07.1997

The six wheeled robot rover Mars Sojourner rolled onto the martian surface on July 5th (Sol 2) at about 10:40 PM Pacific Daylight Time. This image confirms that its descent down the lander's rear deployment ramp was successful.

Sakurajima Volcano with Lightning
10.02.2010

Why does a volcanic eruption sometimes create lightning? Pictured above, the Sakurajima volcano in southern Japan was caught erupting early last month. Magma bubbles so hot they glow shoot away as liquid rock bursts through the Earth's surface from below.

MESSENGER s Degas View
22.06.2011

Now imaging inner planet Mercury from orbit, the MESSENGER spacecraft wide angle camera has returned this impressive color view of Degas Crater, with a full resolution of 90 meters per pixel. Named...

Curiosity Drops In
8.08.2012

Just as it captured the Phoenix lander parachuting to Mars in 2008, the HiRise camera onboard the Mars Reconnaissance Orbiter (MRO) snapped this picture of the Curiosity rover's spectacular descent toward its landing site on August 5 (PDT).

Unusual Spheres on Mars
25.09.2012

Why are these strange little spheres on Mars? The robotic rover Opportunity chanced across these unusually shaped beads earlier this month while exploring a place named Kirkwood near the rim of Mars' Endeavor Crater.