Mysterious Black Water in Florida Bay
2.04.2002

What is causing the water in Florida Bay to turn black? The mysterious black color could be seen as early as last December in images taken by the SeaWIFS instrument on board the Earth-orbiting SeaStar satellite.

NGC 3132: The Eight Burst Nebula
10.11.1998

It's the dim star, not the bright one, near the center of NGC 3132 that created this odd but beautiful planetary nebula. Nicknamed the Eight-Burst Nebula and the Southern Ring Nebula, the glowing gas originated in the outer layers of a star like our Sun.

Announcing Nova Carinae 2018
25.03.2018

How bright will Nova Carinae 2018 become? The new nova was discovered only last week. Although novas occur frequently throughout the universe, this nova, cataloged as ASASSN-18fv, is so unusually bright in the skies of Earth that it is now easily visible through binoculars in the southern hemisphere.

A Rusty Sunset on Mars
4.08.1997

On Mars, sunsets can appear salmon pink. The unusual color is partly due to rust: oxidized iron from Martian dust circulating in the Martian atmosphere. Clouds appear in the morning and evening, but usually evaporate in the midday Sun.

La Nina Earth
15.02.1999

La Niña is a temporary climate change caused by unusually cold water in the central Pacific Ocean. Cold water topping an unusually low sea level is shown as purple in the above false-color picture taken by the orbiting TOPEX/Poseidon satellite in mid-January.

Shoreline Terrain on Saturns Titan
21.09.2005

What could have created this unusual terrain on Saturn's moon Titan? The robotic Cassini spacecraft now orbiting Saturn swooped once again, earlier this month, past the Solar System's most enigmatic moon and radar imaged a rich but unusual region that appears to be some sort of shoreline.

An Unexpected Flare from the Crab Nebula
23.05.2011

Why does the Crab Nebula flare? No one is sure. The unusual behavior, discovered over the past few years, seems only to occur in very high energy light -- gamma rays. As recently...

Reflection Nebula NGC 1435
1.03.1999

Reflection nebulae reflect light from a nearby star. Many small carbon grains in the nebula reflect the light. The blue color typical of reflection nebula is caused by blue light being more efficiently scattered by the carbon dust than red light.

The Keyhole Nebula
23.05.1999

The dark dusty Keyhole Nebula gets its name from its unusual shape. Officially designated NGC 3324, the Keyhole Nebula is a smaller region superposed on the larger Eta Carina Nebula. These nebulae were created by the dying star Eta Carina, which is prone to violent outbursts during its final centuries.

APOD: 2025 February 4 Б Anticrepuscular Rays: A Rainbow Fan over Spain
4.02.2025

Yes, but can your rainbow do this? Late in the day, the Sun set as usual toward the west. However, on this day, the more interesting display was 180 degrees around -- toward the east. There, not only was a rainbow visible, but an impressive display of anticrepuscular rays from the rainbow's center.