APOD: 2023 March 19 Б Equinox at the Pyramid of the Feathered Serpent
18.03.2023

To see the feathered serpent descend the Mayan pyramid requires exquisite timing. You must visit El Castillo -- in Mexico's Yucatцn Peninsula -- near an equinox. Then, during the late afternoon if the sky is clear, the pyramid's own shadows create triangles that merge into the famous illusion of a slithering viper.

September Sunrise Shadows
23.09.2022

The defining astronomical moment for this September's equinox was on Friday, September 23, 2022 at 01:03 UTC, when the Sun crossed the celestial equator moving south in its yearly journey through planet Earth's sky.

Equinox on a Spinning Earth
21.09.2021

When does the line between night and day become vertical? Today. Today is an equinox on planet Earth, a time of year when day and night are most nearly equal. At an equinox, the Earth's terminator -- the dividing line between day and night -- becomes vertical and connects the north and south poles.

Equinox in the Sky
21.09.2020

Does the Sun set in the same direction every day? No, the direction of sunset depends on the time of the year. Although the Sun always sets approximately toward the west, on an equinox like today the Sun sets directly toward the west.

Equinox Sunrise Around the World
29.09.2022

A planet-wide collaboration resulted in this remarkable array of sunrise photographs taken around the September 2022 equinox. The images were contributed by 24 photographers, one in each of 24 nautical time zones around the world.

Uranian Moons, Rings, And Clouds
25.11.1997

The giant planet Uranus is faint and featureless when viewed in visible light. But this pair of near-infrared mosaics from the Hubble Space Telescope's NICMOS camera reveals moons, rings, and clouds of this distant gas planet.

Equinox + 1
19.03.2004

Twice a year, at the Spring and Fall equinox, the Sun rises due east. In an emphatic demonstration of this celestial alignment, photographer Joe Orman recorded this inspiring image of the Sun rising exactly along the east-west oriented Western Canal, in Tempe,Arizona, USA.

Uranus' Largest Moon: Titania
3.03.1996

Titania's tortured terrain is a mix of valleys and craters. NASA's interplanetary robot spacecraft Voyager 2 passed this moon of Uranus in 1986 and took the above photograph. The photograph was then transmitted back to earth by radio.

Irregular Moons Discovered Around Uranus
2.11.1997

Where did these two irregular moons of Uranus originate? Last week two previously undiscovered moons of the distant gas planet were confirmed, the first in irregular orbits. All fifteen previously known moons of Uranus are 'regular', circling near the planet's equator. Most of these were discovered by the passing Voyager 2 spacecraft in 1986.

Uranus: The Tilted Planet
26.08.2001

Uranus is the third largest planet in our Solar System after Jupiter and Saturn. Uranus is composed mostly of rock and ices, but with a thick hydrogen and helium atmosphere. The blue hue of Uranus' atmosphere arises from the small amount of methane which preferentially absorbs red light.