Sundogs over the VLA
23.08.1999

What if you woke up one morning and saw more than one Sun in the sky? Most probably, you would be seeing sundogs, extra-images of the Sun created by falling ice-crystals in the Earth's atmosphere. As water freezes in the atmosphere, small, flat, six-sided, ice crystals might be formed.

Massive Stars in NGC 6357
9.10.2008

Massive Stars lie within NGC 6357, an expansive emission nebula complex some 8,000 light-years away in the tail of the constellation Scorpius. In fact, positioned just below center in this close-up view...

Massive Stars in NGC 6357
5.02.2016

Massive stars lie within NGC 6357, an expansive emission nebula complex some 6,500 light-years away toward the tail of the constellation Scorpius. In fact, positioned near center in this ground-based close-up...

APOD: 2007 February 24- X rays and the Eagle Nebula
24.02.2007

The premier Chandra X-ray Observatory images of M16, the Eagle Nebula, show many bright x-ray sources in the region. Most of the x-ray sources are energetic young stars. They are seen here as colored spots superimposed on the Hubble's well-known optical view of M16's light-year long Pillars of Creation.

Analemma Over the Porch of Maidens
21.12.2008

If you took a picture of the Sun at the same time each day, would it remain in the same position? The answer is no, and the shape traced out by the Sun over the course of a year is called an analemma.

Aristarchus' Unbelievable Discoveries
14.09.1996

Here lived one of the greatest thinkers in human history. Aristarchus lived on the Greek island of Samos, a small island in the center of the above picture that can be identified with a good map.

Aristarchus' Unbelievable Discoveries
8.11.1997

Here lived one of the greatest thinkers in human history. Aristarchus lived on the Greek island of Samos, a small island in the center of the above picture that can be identified with a good map.

Bright from the Heart Nebula
27.10.2015

What's that inside the Heart Nebula? First, the large emission nebula dubbed IC 1805 looks, in whole, like a human heart. The nebula glows brightly in red light emitted by its most prominent element: hydrogen.

In the Heart of the Heart Nebula
14.02.2022

What excites the Heart Nebula? First, the large emission nebula dubbed IC 1805 looks, in whole, like a human heart. Its shape perhaps fitting of the Valentine's Day, this heart glows brightly in red light emitted by its most prominent element: excited hydrogen.

In the Heart of the Heart Nebula
14.02.2018

What's that inside the Heart Nebula? First, the large emission nebula dubbed IC 1805 looks, in whole, like a human heart. It's shape perhaps fitting of the Valentine's Day, this heart glows brightly in red light emitted by its most prominent element: hydrogen.