APOD: 2023 August 23 Б The Meteor and the Galaxy
23.08.2023

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.

A Perseid Aurora
9.08.2003

Just after the Moon set but before the Sun rose in the early morning hours of 2000 August 12, meteors pelted the Earth from the direction of the constellation Perseus, while ions pelted the Earth from the Sun.

Layered Rocks near Mount Sharp on Mars
8.02.2015

What caused these Martian rocks to be layered? The leading hypothesis is an ancient Martian lake that kept evaporating and refilling over 10 million years -- but has now remained dry and empty of water for billions of years.

Night and Day in Melas Chasma on Mars
16.12.2002

What types of terrain are found on Mars? Part of the answer comes from thermal imaging by the robot spacecraft 2001 Mars Odyssey currently orbiting Mars. The above picture is a superposition of two infrared images, a black and white image taken during Martian daylight and a false-color image taken at night.

Sea and Sky Glows over the Oregon Coast
4.09.2022

Every step caused the sand to light up blue. That glow was bioluminescence -- a blue radiance that also lights the surf in this surreal scene captured in mid-2018 at Meyer's Creek Beach in Oregon, USA. Volcanic stacks dot the foreground sea, while a thin fog layer scatters light on the horizon.

Lunar Dust and Duct Tape
28.03.2025

Why is the Moon so dusty? On Earth, rocks are weathered by wind and water, creating soil and sand. On the Moon, eons of constant micrometeorite bombardment have blasted away at the rocky surface creating a layer of powdery lunar soil or regolith.

Lunar Dust and Duct Tape
10.11.2001

Why is the Moon dusty? On Earth, rocks are weathered by wind and water, creating soil and sand. On the Moon, the long history of micrometeorite bombardment has blasted away at the rocky surface creating a layer of powdery lunar soil or regolith. This lunar regolith could be a scientific and industrial bonanza.

A 2000 Leonid Through Orion
20.11.2000

The Leonid Meteor Shower this year could be described as good but not great. During November 17 and 18 the Earth crossed through several streams of sand-sized grit left orbiting the Sun by Comet Tempel-Tuttle. Several distinct peaks in meteor activity were reported, with

Spirit Rover Reaches the Columbia Hills on Mars
28.06.2004

The Spirit robotic rover on Mars has now reached the Columbia Hills on Mars. Two of the hills are shown on approach near the beginning of June. The above true-color picture shows very nearly what a human would see from Spirit's vantage point.

Saturn's Rings Seen Sideways
24.05.1997

Saturn's rings are actually very thin. This picture from the Hubble Space Telescope was taken on August 6, 1995 when the rings lined up sideways as seen from Earth. Saturn's largest moon Titan is seen on the left, and Titan's shadow can be seen on Saturn's cloud tops!