APOD: 2023 August 23 Б The Meteor and the Galaxy
22.08.2023

It came from outer space. It -- in this case a sand-sized bit of a comet nucleus -- was likely ejected many years ago from Sun-orbiting Comet Swift-Tuttle, but then continued to orbit the Sun alone.

The Aurora and the Sunrise
30.04.2018

On the International Space Station (ISS), you can only admire an aurora until the sun rises. Then the background Earth becomes too bright. Unfortunately, after sunset, the rapid orbit of the ISS around the Earth means that sunrise is usually less than 47 minutes away.

Apollo 17: The Crescent Earth
28.04.2021

Our fair planet sports a curved, sunlit crescent against the black backdrop of space in this stunning photograph. From the unfamiliar perspective, the Earth is small and, like a telescopic image of a distant planet, the entire horizon is completely within the field of view.

A Partial Eclipse Over the Golden Gate Bridge
12.06.2002

Part of the Sun disappeared behind the Moon earlier this week. Previously, the waning Moon was best visible from all places on Earth during the early morning hours because it trailed the Sun. As the Moon orbited the Earth, however, it caught up to the Sun and passed it on the sky.

The Flare and the Galaxy
1.09.2015

Is this person throwing a lightning bolt? No. Despite appearances, this person is actually pointing in the direction of a bright Iridium flare, a momentary reflection of sunlight off of a communications satellite in orbit around the Earth.

100 Hours of Astronomy Begins
2.04.2009

Today, 100 Hours of Astronomy begins, a cornerstone project of the International Year of Astronomy 2009 celebrating the 400th anniversary of Gallileo's original telescopic exploration of the sky. Running from April 2 through...

APOD: 2025 November 10 Б Micro Moon vs Super Moon
9.11.2025

What was so super about Wednesday's supermoon? Last week, a full moon occurred that appeared slightly larger and brighter than usual. The reason is that the Moon's fully illuminated phase occurred within a short time from perigee - when the Moon was its closest to the Earth in its elliptical orbit.

NICER at Night
31.05.2019

A payload on board the International Space Station, the Neutron star Interior Composition Explorer (NICER) twists and turns to track cosmic sources of X-rays as the station orbits planet Earth every 93 minutes. During orbit nighttime, its X-ray detectors remain on.

Super Earths May Circle Other Stars
19.03.2006

Are "super-Earths" common around other star systems? Quite possibly. Unexpected evidence for this came to light recently when a planet orbiting a distant star gravitationally magnified the light of an even more distant star.

Earthset from the Lunar Reconnaissance Orbiter
3.01.2016

On the Moon, the Earth never rises -- or sets. If you were to sit on the surface of the Moon, you would see the Earth just hang in the sky. This is because the Moon always keeps the same side toward the Earth.