1999 JM8: A Rock Too Close
1.09.1999

Nearly four kilometers across, the huge rock known as 1999 JM8 silently passed only 8.5 million kilometers from the Earth in early August. The small asteroid was completely unknown before May. Every few centuries, a rock like this impacts the Earth, with the potential to disrupt modern civilization.

Gravitational Anomalies of Mercury
5.05.2015

What's that under the surface of Mercury? The robotic MESSENGER spacecraft that had been orbiting planet Mercury for the past four years had been transmitting its data back to Earth with radio waves of very precise energy.

A Dust Jet from the Surface of Comet 67P
6.11.2017

Where do comet tails come from? There are no obvious places on the nuclei of comets from which the jets that create comet tails emanate. Last year, though, ESA's Rosetta spacecraft not only imaged a jet emerging from Comet 67P/Churyumov-Gerasimenko, but flew right through it.

Aurora Over Clouds
2.04.2001

Aurorae usually occur high above the clouds. The auroral glow is created when fast-moving particles ejected from the Sun impact air molecules high in the Earth's atmosphere. An oxygen molecule, for example, will glow in a green light when reacquiring an electron lost during a collision with a solar particle.

The Full Moon
19.04.1999

Earth has one moon. A symbol in famous love songs, movies, poems, and folklore, many myths about the Moon date back to ancient history. In fact, the name Monday originates from Moon-day. The Moon glows by light it reflects from the Sun and is frequently the brightest object in the night sky.

Lunar Nearside
3.03.2011

About 1,300 images from the Lunar Reconnaissance Orbiter spacecraft's wide angle camera were used to compose this spectacular view of a familiar face - the lunar nearside. But why is there a lunar nearside? The Moon rotates on its axis and orbits the Earth at the same rate, about once every 28 days.

A Solar Filament Erupts
17.09.2012

What's happened to our Sun? Nothing very unusual -- it just threw a filament. At the end of last month, a long standing solar filament suddenly erupted into space producing an energetic Coronal Mass Ejection (CME).

Touchdown on Asteroid Ryugu
12.03.2019

Last month, humanity bounced a robot off an asteroid. The main reason was to collect a surface sample. Despite concern over finding a safely reboundable touchdown spot, Japan's robotic Hayabusa2 spacecraft successfully touched down -- and bounced right back from -- asteroid Ryugu.

APOD: 2023 November 26 Б A Dust Jet from the Surface of Comet 67P
26.11.2023

Where do comet tails come from? There are no obvious places on the nuclei of comets from which the jets that create comet tails emanate. In 2016, though, ESA's Rosetta spacecraft not only imaged a jet emerging from Comet 67P/Churyumov-Gerasimenko, but flew right through it.

Aurora and Manicouagan Crater from the Space Station
29.05.2018

How many of these can you find in today's featured photograph: an aurora, airglow, one of the oldest impact craters on the Earth, snow and ice, stars, city lights, and part of the International Space Station? Most of these can be identified by their distinctive colors.