The Guardians of Rapa Nui beneath the Milky WayIn the words of today’s astrophotographer, Rositsa Dimitrova, “What have these silent sentinels watched pass across the sky?” The volcanic mo’ai (meaning statue) of Ahu Tongariki stand guard over Rapa Nui (Isla de Pascua, Easter Island), a Polynesian island (annexed by Chile in 1888) located thousands…Read More

A Gravity Map of EarthIs gravity the same over the surface of the Earth? No — in some places you will feel slightly heavier than others. The featured Earth map video shows in colors and exaggerated highs and lows where the gravitational field of Earth is relatively strong and weak. A low spot, where you would feel slightly lighter, can be seen…Read More

Light Pillars and Orion over MoheWhat’s happening at the end of that street? Pictured here are not auroras but light pillars, a phenomenon typically much closer. In most places on Earth, a lucky viewer can see a Sun pillar, a column of light appearing to extend up from the Sun caused by flat fluttering ice-crystals reflecting sunlight from the…Read More

Leaving EarthWhat would it look like to leave planet Earth? Such an event was recorded visually in great detail by the MESSENGER spacecraft as it swung back past the Earth in 2005 on its way in toward the planet Mercury. Earth can be seen rotating in this time-lapse video, as it recedes into the distance. The sunlit half of Earth is so bright that…Read More

Galaxies in the River: NGC 1300 and NGC 1297Spiral NGC 1300 and elliptical NGC 1297 are galaxies that lie on the banks of the southern constellation Eridanus (The River). At 70 million light-years distant or more, both are members of the Eridanus Galaxy Cluster. About 100,000 light-years across, at lower left in this sharp, galaxy group photo NGC…Read More