#Magnitude

Why do two agencies report different magnitudes for the same earthquake? How AFAD, Kandilli and others publish, revise and update recent earthquake lists.

Magnitude measures the energy released by an earthquake, intensity measures the shaking at a place. Learn how Richter, Mw and Mercalli scales differ.

Jupiter and Mars creep through conjunction in the early morning hours. By dawn, Venus and Mercury are up and shining one over the other.

M34 is a bright, young cluster of stars that will fill your eyepiece with points of light, easy to spot in any scope.

A first-magnitude spring, towering cypress swamps, and wildlife-rich forests shape this serene North Florida escape.

A strong earthquake with a preliminary reading of magnitude 5.7 has struck central Japan

An earthquake of magnitude 5.7 hit central Japan on November 8, injuring at least 22. Officials warn of more strong quakes in the next few days.

The quake struck at 1:04 am in Shizuoka Prefecture but no tsunami warning was issued.

Wintry Capella comes into balance with summery Vega. The hairline crescent Moon briefly horns in on Venus and Spica.

Bright planet Venus mingles with the Moon and meets a bright star, plus deep-sky treasures shine in the sky this week.

Many introductory texts (in physics, especially) will define a vector as something that has magnitude and direction. This was a valid definition prior to the end of the 19th century, but mathematicians' concept of what a vector is has considerably…

Now deeper in Leo, our satellite skims close to the bright star Regulus, standing east of Jupiter and Mars in the morning sky.

Venus’ reign is coming to an end as Mars and Jupiter enter the scene and the Moon occults Regulus in the southern sky this month.

Saturn is visible as darkness falls with Neptune nearby, the Full Moon crosses the Pleiades, and Mars and Jupiter dominate before dawn.

Our satellite passes several planets while Venus meets Spica in a close conjunction and spooky season culminates in the sky this week.

The Red Planet reaches the border of Cancer and Leo; tomorrow it will have crossed the line into the Lion, sharing it with Jupiter.

There were no immediate reports of damage or casualties following the earthquake.

This crescent-shaped cluster shines in northern Cassiopeia, visible all night long as the stars wheel around the North Celestial Pole.

Even with a bright Moon in the sky, you can easily trace this “waterfall” of stars to its end in the spray of open cluster NGC 1502.