At the Shadow s Edge
25.11.2021

Shaped like a cone tapering into space, the Earth's dark central shadow or umbra has a circular cross-section. It's wider than the Moon at the distance of the Moon's orbit though. But during the lunar eclipse of November 18/19, part of the Moon remained just outside the umbral shadow.

A Double Lunar Analemma over Turkey
10.10.2022

An analemma is that figure-8 curve you get when you mark the position of the Sun at the same time each day for one year. But the trick to imaging an analemma of the Moon is to wait bit longer.

APOD: 2024 September 8 Б M31: The Andromeda Galaxy
8.09.2024

The most distant object easily visible to the unaided eye is M31, the great Andromeda Galaxy. Even at some two and a half million light-years distant, this immense spiral galaxy -- spanning over 200,000 light years -- is visible, although as a faint, nebulous cloud in the constellation Andromeda.

Jupiter and the Meteors from Gemini
18.12.2025

Jupiter, the Solar System's ruling gas giant, is the brightest celestial beacon at the center of this composite night skyscape. The scene was constructed by selecting the 40 exposures containing meteors from about...

Tempel-Tuttle: The Leonid Comet
30.01.1998

Star trails streak this composite time exposure of Comet Tempel-Tuttle recorded by T. Puckett on January 26. Presently passing through the inner solar system on its 33 year orbit around the Sun, Tempel-Tuttle has brightened unexpectedly, but binoculars or small telescopes are still required to visually observe it.

Sand Dunes on Mars
26.02.2001

Sand dunes on Mars can appear exotic. The dark dunes above might be compared to shark's teeth or chocolate confections. In reality, they arise from the complex relationship between the sandy surface and high winds on Mars.

Asteroid Eros Reconstructed
5.06.2001

Orbiting the Sun between Mars and Earth, asteroid 433 Eros was visited by the robot spacecraft NEAR-Shoemaker in 2000 February. Some of the 100,000+ images taken by NEAR of the tumbling space rock have been combined into the above high-resolution composite.

Warped Spiral Galaxy ESO 510 13
3.08.2001

How did spiral galaxy ESO 510-13 get bent out of shape? The disks of many spirals are thin and flat, but not solid. Spiral disks are loose conglomerations of billions of stars and diffuse gas all gravitationally orbiting a galaxy center.

A Perseid Meteor
11.08.1997

Tonight the Perseid Meteor Shower reaches its maximum. Grains of rocky ice will streak across the sky as they evaporate during entry into Earth's atmosphere. These ice chips were shed from Comet Swift-Tuttle. The Perseids result from the annual crossing of the Earth through Comet Swift-Tuttle's orbit.

The Helix Nebula from Blanco and Hubble
29.12.2004

How did a star create the Helix nebula? The shapes of planetary nebula like the Helix are important because they likely hold clues to how stars like the Sun end their lives. Recent observations...