A Perseid Meteor and the Milky Way
3.08.2021

It was bright and green and flashed as it moved quickly along the Milky Way. It left a trail that took 30 minutes to dissipate. Given the day, August 12, and the direction, away...

APOD: 2023 July 19 Б Chandrayaan 3 Launches to the Moon
19.07.2023

Birds don't fly this high. Airplanes don't go this fast. The Statue of Liberty weighs less. No species other than human can even comprehend what is going on, nor could any human just a millennium ago. The launch of a rocket bound for space is an event that inspires awe and challenges description.

APOD: 2024 August 11 Б Animation: Perseid Meteor Shower
11.08.2024

Where do Perseid meteors come from? Mostly small bits of stony grit, Perseid meteoroids were once expelled from Comet Swift-Tuttle and continue to follow this comet's orbit as they slowly disperse. The featured animation depicts the entire meteoroid stream as it orbits our Sun.

APOD: 2024 September 3 Б Quarter Moon and Sister Stars
3.09.2024

Nine days ago, two quite different sky icons were imaged rising together. Specifically, Earth's Moon shared the eastern sky with the sister stars of the Pleiades cluster, as viewed from Alberta, Canada. Astronomical...

APOD: 2026 August 28 Б The Sky Turns Above Paranal
28.08.2026

At the latitude of ESO's Paranal Observatory in Chile, about 25 degrees south, Earth's rotation moves the planet's surface eastward at over 1,500 kilometers per hour. And while that's faster than the speed of sound at sea level, the motion is imperceptible.

GRAIL Maps the Moons Gravity
19.03.2013

How did the Moon form? To help find out, NASA launched the twin Gravity Recovery and Interior Laboratory (GRAIL) satellites in 2011 to orbit and map the Moon's surface gravity in unprecedented detail.

Io: Moon Over Jupiter
20.04.2001

How big is the Jovian moon Io? The most volcanic body in the Solar System, Io (usually pronounced "EYE-oh") is 3,600 kilometers in diameter, about the size of planet Earth's single large natural satellite.

Artificial Night Sky Brightness
27.08.2001

Where have all the dim stars gone? From many places on the Earth including major cities, the night sky has been reduced from a fascinating display of hundreds of stars to a diffuse glow through which only a handful of stars are visible.

An Anomalous SETI Signal
28.07.2002

No one knows for sure what caused this signal. There is a slight possibility that it just might originate from an extraterrestrial intelligence. The bright colors on the blue background indicate that an anomalous signal was received here on Earth by a radio telescope involved in a Search for Extraterrestrial Intelligence (SETI).

The Witch Head Nebula
29.12.2003

Double, double toil and trouble; Fire burn, and cauldron bubble -- maybe Macbeth should have consulted the Witch Head Nebula. This suggestively shaped reflection nebula is associated with the bright star Rigel in the constellation Orion.