The Moon and All the Crashes
19.09.1996

A clear blue summer sky finally grows dark and the new telescope, hastily set up in the backyard, generates excitment and anticipation. "I bought it for the kids ...", Dad assures himself as he over-anxiously supervises the two young boys' efforts to center a bright, first quarter Moon, in the finder.

Spot the Moon
2.01.2012

Where's the full Moon? Somewhere in this image, the Earth's Moon is hiding. The entire Moon is visible, in its completely full phase, in plain sight. Even the photographer's keen...

The Flash Spectrum of the Sun
11.03.2016

In a flash, the visible spectrum of the Sun changed from absorption to emission on March 9 during the total solar eclipse. That fleeting moment, at the beginning the total eclipse phase, is captured by telephoto lens and diffraction grating in this image from clearing skies over Ternate, Indonesia.

A Blue Banded Blood Moon
30.11.2021

What causes a blue band to cross the Moon during a lunar eclipse? The blue band is real but usually quite hard to see. The featured HDR image of last week's lunar eclipse, however -- taken from Yancheng, China -- has been digitally processed to equalize the Moon's brightness and exaggerate the colors.

Venus: Earth's Cloudy Twin
23.09.1996

If Venus weren't so cloudy it would be more similar to Earth. This picture by the Galileo spacecraft shows just how cloudy Venus is. Venus is very similar to Earth in size and mass - and so is sometimes referred to as Earth's sister planet - but Venus has a quite different climate.

Mars, Ceres, Vesta
10.04.2014

That bright, ruddy star you've recently noticed rising just after sunset isn't a star at all. That's Mars, the Red Planet. Mars is now near its 2014 opposition (April 8) and closest approach (April 14), looping through the constellation Virgo opposite the Sun in planet Earth's sky.

Moon Pi and Mountain Shadow
13.03.2025

What phase of the Moon is 3.14 radians from the Sun? The Full Moon, of course. Even though the Moon might look full for several days, the Moon is truly at its full phase when it is Pi radians (aka 180 degrees) from the Sun in ecliptic longitude.

Colors of the Moon
10.11.2020

What color is the Moon? It depends on the night. Outside of the Earth's atmosphere, the dark Moon, which shines by reflected sunlight, appears a magnificently brown-tinged gray. Viewed from inside the Earth's atmosphere, though, the moon can appear quite different.

Solar Eclipse over Queensland
15.11.2012

This month's New Moon brought a total solar eclipse to parts of planet Earth on November 13 (UT). Most of the total eclipse track fell across the southern Pacific, but the Moon's dark umbral shadow began its journey in northern Australia on Wednesday morning, local time.

Highlights of the Summer Sky
26.06.2018

What can you see in the night sky this summer? The featured graphic gives a few highlights for Earth's northern hemisphere. Viewed as a clock face centered at the bottom, early (northern) summer sky events fan out toward the left, while late summer events are projected toward the right.