APOD: 2023 November 6 Б Red Aurora over Italy
6.11.2023

What was that red glow on the horizon last night? Aurora. Our unusually active Sun produced a surface explosion a few days ago that sent out a burst of electrons, protons, and more massive charged nuclei.

Strange Orange Soil on the Moon
23.05.2001

How did orange soil appear on the Moon? This mystery began when astronaut Harrison Schmidt noticed the off-color patch near Apollo 17's Taurus-Littrow landing site in 1972. Schmidt and fellow astronaut Eugene Cernan scooped up some of the unusual orange soil for detailed inspection back on Earth.

The International Space Station Transits the Sun
30.07.2008

That's no sunspot. It's the International Space Station (ISS) caught by chance passing in front of the Sun. Sunspots, individually, have a dark central umbra, a lighter surrounding penumbra, and no solar panels.

Blue Straggler Stars in Globular Cluster M53
9.04.2012

If our Sun were part of M53, the night sky would glow like a jewel box of bright stars. M53, also known as NGC 5024, is one of about 250 globular clusters that survive in our Galaxy.

APOD: 2025 June 22 Б A Berry Bowl of Martian Spherules
22.06.2025

How were these unusual Martian spherules created? Thousands of unusual gray spherules made of iron and rock and dubbed blueberries were found embedded in and surrounding rocks near the landing site of the robot Opportunity rover on Mars in 2004.

APOD: 2025 July 15 Б Collapse in Hebes Chasma on Mars
15.07.2025

What's happened in Hebes Chasma on Mars? Hebes Chasma is a depression just north of the enormous Valles Marineris canyon. Since the depression is unconnected to other surface features, it is unclear where the internal material went.

Mysterious Acid Haze on Venus
26.02.2008

Why did an acidic haze spread across Venus? The unusual clouds were discovered last July by ESA's robotic Venus Express spacecraft currently orbiting Venus. The bright and smooth haze was found by Venus...

Large Sunspot Groups 10484 and 10486
27.10.2003

Two unusually large sunspot groups are now crossing the face of the Sun. Each group, roughly the size of Jupiter, is unusual not only for its size but because it is appearing over three years after solar maximum, the peak of solar surface activity.

Asperatus Clouds Over New Zealand
17.04.2016

What kind of clouds are these? Although their cause is presently unknown, such unusual atmospheric structures, as menacing as they might seem, do not appear to be harbingers of meteorological doom. Known informally...

A Deep Sky Behind an Eclipsed Moon
24.05.2022

The plan was to capture a picturesque part of the sky that was hosting an unusual guest. The result included a bonus Б an additional and unexpected guest. The beautiful background features part...