Noctilucent Clouds and Aurora Over Scotland
19.08.2013

Why would the sky still glow after sunset? Besides stars and the band of our Milky Way galaxy, the sky might glow because it contains either noctilucent clouds or aurora. Rare individually, both are visible in the above time lapse movie taken over Caithness, Scotland, UK taken during a single night earlier this month.

Firing Lasers to Tame the Sky
9.02.2021

Why do stars twinkle? Our atmosphere is to blame as pockets of slightly off-temperature air, in constant motion, distort the light paths from distant astronomical objects. Atmospheric turbulence is a problem for astronomers because it blurs the images of the sources they want to study.

Gigantic Jet Lightning from Puerto Rico
28.09.2021

Have you ever seen a gigantic jet? They are extremely rare but tremendously powerful. Gigantic jets are a type of lightning discharge documented only this century that occur between some thunderstorms and the Earth's ionosphere high above them.

Crumbling Comet Schwassmann Wachmann 3 Approaches
26.04.2006

A crumbling comet will soon pass near the Earth. Comet 73P/Schwassmann-Wachmann 3 is brightening and may even be visible to the unaided eye when the fragmented comet zooms past Earth during the middle of next month.

Churning Clouds on Jupiter
10.08.2020

Where is Jupiter's ammonia? Gaseous ammonia was expected to be seen in Jupiter's upper atmosphere by the orbiting Juno spacecraft -- but in many clouds is almost absent. Recent Juno data, however, gives some clues: some high-level clouds appear to be home to an unexpected type of electrical discharge dubbed shallow lightning.

M74: The Perfect Spiral
11.08.2013

If not perfect, then this spiral galaxy is at least one of the most photogenic. An island universe of about 100 billion stars, 32 million light-years away toward the constellation Pisces, M74 presents a gorgeous face-on view.

The Infrared Visible Andromeda
12.12.2014

This remarkable synthetic color composite image was assembled from archives of visible light and infrared astronomy image data. The field of view spans the Andromeda Galaxy (M31), a massive spiral a mere 2.5 million light-years away. In fact, with over twice the diameter of our own Milky Way, Andromeda is the largest nearby galaxy.

Planet Building in HD 100546
2.05.2001

More than 100 billion boulders may be swarming in the disk around nearby star HD 100546. In a scene thought similar to the early years of our own Solar System, ever larger rocks are growing by colliding and accreting dust as the messy business of planet formation appears to be underway.

The Pencil Nebula in Red and Blue
12.08.2018

This shock wave plows through interstellar space at over 500,000 kilometers per hour. Near the top and moving up in this sharply detailed color composite, thin, bright, braided filaments are actually long ripples in a cosmic sheet of glowing gas seen almost edge-on.

APOD: 2024 August 13 Б Giant Jet from the International Space Station
12.08.2024

What's that on the horizon? When circling the Earth on the International Space Station early last month, astronaut Matthew Dominick saw an unusual type of lightning just beyond the Earth's edge: a gigantic jet. The powerful jet appears on the left of the featured image in red and blue.