Diamond Rings and Baily s Beads
27.03.2015

Near the March 20 equinox the cold clear sky over Longyearbyen, Norway, planet Earth held an engaging sight, a total eclipse of the Sun. The New Moon's silhouette at stages just before...

The Ecliptic Plane
21.09.1996

The Plane of the Ecliptic is illustrated in this Clementine star tracker camera image which reveals (from right to left) the Moon lit by Earthshine, the Sun's corona rising over the Moon's dark limb, and the planets Saturn, Mars, and Mercury.

Moon Shadow on Jupiter
27.04.2022

What is that large dark spot on Jupiter? It's the shadow of Io, one of Jupiter's largest moons. When Jupiter's moons cross between the Jovian giant and the Sun, they created shadows just like when the Earth's moon crosses between the Earth and the Sun.

Partial Eclipse, Cloudy Day
21.12.2001

Welcome to the December Solstice, first day of winter in the north and summer in the southern hemisphere of planet Earth. Today the Sun reaches its southernmost declination in the sky at 19:21 Universal Time.

Pluto and Charon Eclipse a Triple Star
11.09.2002

Occasionally, a planet in our Solar System will pass in front of a bright star. Since stars and planets take up so little space on the sky, such events are quite rare. Two months ago, however, Pluto and its large moon Charon passed in front of a comparatively bright triple star system known as P126.

APOD: 2026 February 11 Б A Year of Sunspots
11.02.2026

How many sunspots can you see? The central image shows the many sunspots that occurred in 2025, month by month around the circle, and all together in the grand central image. Each sunspot is magnetically cooled and so appears dark -- and can last from days to months.

Habitable Worlds
3.03.2014

Is Earth the only known world that can support life? In an effort to find life-habitable worlds outside our Solar System, stars similar to our Sun are being monitored for slight light decreases that indicate eclipsing planets. Many previously-unknown planets are being found, including over 700 worlds recently uncovered by NASA's Kepler satellite.

APOD: 2025 January 15 Б Wolf Moon Engulfs Mars
15.01.2025

Does the Moon ever engulf Mars? Yes, but only in the sense that it moves in front, which happens on rare occasions. This happened just yesterday, though, as seen from some locations in North America and western Africa.

Kepler 16b: A Planet with Two Suns
20.09.2011

If you stay up long enough, you can watch both suns set. Such might be a common adage from beings floating in the atmosphere of Kepler 16b, a planet recently discovered by the space-based Kepler satellite. The above animated video shows how the planetary system might look to a visiting spaceship.

The Flash Spectrum of the Sun
7.09.2017

In clear Madras, Oregon skies, this colorful eclipse composite captured the elusive chromospheric or flash spectrum of the Sun. Only three exposures, made on August 21 with telephoto lens and diffraction grating, are aligned in the frame.