Photo of the Day In northern hemisphere spring, bright star Regulus is easy to spot above the eastern horizon. The alpha star of the constellation Leo, Regulus is the spiky star centered in this telescopic field of view. A mere 79 light-years distant, Regulus is a hot, rapidly spinning star that is known to [...]
Photo of the Day How did a star form this beautiful nebula? In the middle of emission nebula NGC 6164 is an unusually massive star. The central star has been compared to an oyster's pearl and an egg protected by the mythical sky dragons of Ara. The star, visible in the center of the [...]
Photo of the Day Yes, but can your volcano do this? To the surprise of some, Mt. Etna emits, on occasion, smoke rings. Technically known as vortex rings, the walls of the volcano slightly slow the outside of emitted smoke puffs, causing the inside gas to move faster. A circle of low pressure develops [...]
Photo of the Day The explosion is over, but the consequences continue. About eleven thousand years ago, a star in the constellation of Vela could be seen to explode, creating a strange point of light briefly visible to humans living near the beginning of recorded history. The outer layers of the star crashed into [...]
Photo of the Day Something strange happened to this galaxy, but what? Known as the Cigar Galaxy and cataloged as M82, red glowing gas and dust are being cast out from the center. Although this starburst galaxy was surely stirred up by a recent pass near its neighbor, large spiral galaxy M81, this doesn't [...]
Photo of the Day How does a total solar eclipse end? Yes, the Moon moves out from fully blocking the Sun, but in the first few seconds of transition, interesting things appear. The first is called a diamond ring. Light might stream between mountains or through relative lowlands around the Moon's edge, as seen [...]
Photo of the Day What wonders appear when the Moon blocks the Sun? For many eager observers of Monday’s total eclipse of the Sun, the suddenly dark sky included the expected corona and two (perhaps surprise) planets: Venus and Jupiter. Normally, in recent days, Venus is visible only in the morning when the Sun [...]
Photo of the Day Captured in this snapshot, the shadow of the Moon came to Lake Magog, Quebec, North America, planet Earth on April 8. For the lakeside eclipse chasers, the much anticipated total solar eclipse was a spectacle to behold in briefly dark, but clear skies. Of course Lake Magog was one of [...]
Photo of the Day How does a comet tail change? It depends on the comet. The ion tail of Comet 12P/Pons–Brooks has been changing markedly, as detailed in the featured image sequenced over nine days from March 6 to 14 (top to bottom). On some days, the comet's ion tail was relatively long and [...]
Photo of the Day Will the sky be clear enough to see the eclipse? This question is already on the minds of many North Americans hoping to see tomorrow's solar eclipse. This question was also on the mind of many people attempting to see the total solar eclipse that crossed North America in August [...]
