2006 transit of Mercury
Laser adaptive optics system in Chile
Hubble view of Bubble Nebula

StarDate Radio: May 6 — Mercury Transit

A tiny black dot will cross the face of the Sun early Monday: Mercury, the Sun’s closest planet. The entire...More »

StarDate Radio: May 5 — Head Cases

The strong man and the snake handler go head to head on spring and summer nights.

Rasalhague is the star...More »

Stargazing: May 5

The star Rasalhague represents the head of Ophiuchus, the serpent bearer, while Rasalgethi is the head of Hercules. Rasalhague climbs...More »

StarDate Radio: May 4 — Van Allen Belts

The first discovery of the Space Age was two intense radiation belts that encircle Earth. They’re called the Van Allen...More »

Stargazing: May 4

Like its constellation, Hercules, the star Mu Herculis is faint and difficult to find. Yet the star is of particular...More »

StarDate Radio: May 3 — Evening Mars

Mars is pushing into the pre-midnight sky, and getting brighter as it does so. In about three weeks, it’ll...More »

Stargazing: May 3

Mars is pushing into the pre-midnight sky, getting brighter as it does so. Tonight, look for the orange planet quite...More »

StarDate Radio: May 2 — Making Fluorine

Neutrinos are ghostly particles that almost never interact with matter. In fact, trillions of them shoot harmlessly through your body...More »

Stargazing: May 2

Sirius, the brightest star in the night sky, is disappearing in the evening twilight. Look for the star blazing low...More »

StarDate Radio: May 1 — Beltane

The modern western calendar tells us that summer arrives in the northern hemisphere this year on June 20th — the...More »

Stargazing: May 1

In the calendars of ancient Ireland and Scotland, May 1 was Beltane, a day dedicated to celebrating the end of...More »

StarDate Radio: April 30 — Leaving the Nest

Our solar system is heading into the aftermath of a stellar breakup — a stream of stars that split away...More »

Stargazing: April 30

Corona Borealis, the northern crown, is a pretty semicircle of stars that’s about a third of the way up the...More »

Current Magazine

cover of May-June issue

Our Summer Reading Issue is here! In it, you'll find excerpts from new books in astronomy and space science. We'll also bring you skywatching tips and charts, plus the latest astronomy news.

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