This isotope is found at a ratio of about one per 2,500 helium-4 ions, the latter being the common version of helium.

For skywatchers in the northeastern U.S. and Canada this week, it will appear as though the moon took a bite out of the sun. The eclipse will occur in the early hours of Saturday, March 29, ...

(Partial solar eclipses occurs when the moon comes between the Earth and the sun to partially cover the sun, resulting in a crescent shape.) But people in 13 states – from West Virginia to Maine ...

The unique, 50-mile-wide X shape is expected to appear on the moon tonight, March 6 ... the craters' position would see the ...

A long, long time ago, the Sun and the Moon walked the earth, living among humans as equals. Without their light, the Earth turned peacefully beneath the light of the stars. For generations ...

Unlike a total solar eclipse, part of the sun is still visible during a partial solar eclipse, so there is no darkening of the sky or visible solar corona. This new moon of March 2025 will create ...

and Regiomontanus—in the Moon's rugged southern highlands. The contrasting light and shadows create the striking X shape as the Sun grazes these craters during the lunar phase. The distinctive ...

Also referred to as "devil's horns" or "solar horns," this stunning visual phenomenon happens when the moon partially covers the sun, particularly during an "eclipse sunrise," and the two "points ...

Peak illumination does not always coincide with the best viewing time, which occurs after the sun has fully set. Peak illumination marks the moment when the full moon is perfectly opposite the sun ...