APOD: 2023 March 19 Б Equinox at the Pyramid of the Feathered Serpent
19.03.2023

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.

APOD: 2026 March 15 Б Equinox at the Pyramid of the Feathered Serpent
15.03.2026

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.

Meteors and Auroras over Iceland
13.12.2021

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

GRB 990123 Host Galaxy Imaged
10.02.1999

Do the powerful explosions known as gamma-ray bursts (GRBs) originate in galaxies? This subject took on new light yesterday with the release of a Hubble Space Telescope image of the sky surrounding GRB 990123. This burst was first detected only two weeks ago and cataloged as one of the most powerful GRBs ever.

Tails of Comet Lemmon
6.05.2013

What caused the interestingly intricate tails that Comet Lemmon displayed earlier this year? First of all, just about every comet that nears the Sun displays two tails: a dust tail and an ion tail.

The Solar System s Planet Trails
1.07.2022

Stars trail through a clear morning sky in this postcard from a rotating planet. The timelapse image is constructed from consecutive exposures made over nearly three hours with a camera fixed to a tripod beside the Forbidden City in Beijing, China on June 24.

APOD: 2025 July 19 Б Messier 6
19.07.2025

The sixth object in Charles Messier's famous catalog of things which are not comets, Messier 6 is a galactic or open star cluster. A gathering of 100 stars or so, all around 100 million years young, M6 lies some 1,600 light-years away toward the central Milky Way in the constellation Scorpius.

Cygnus Nebulosities
23.10.2003

Looking toward the constellation Cygnus, a stunning and complex region of nebulae strewn along the plane of our Milky Way galaxy is revealed in this unique wide-angle sky view. Recorded with a filter designed...

Antarctic Analemma
23.09.2015

Does the Sun return to the same spot on the sky every day? No. A better and more visual answer to that question is an analemma, a composite image taken from the same spot at the same time over the course of a year.

Tropic of Cancer
2.08.2013

This intriguing monument can be found in Taiwan between the cities of Hualian and Taitong. Split into two sides, it straddles a special circle of latitude on planet Earth, near 23.5 degrees north, known as the Tropic of Cancer.