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Death Valley sliding stone mystery solved

The video above shows a famous sliding stone of Death Valley’s Racetrack Playa in motion. See it? It’s the big rock in the foreground. Watching this video, you become one of the first people on Earth to see a sliding stone in motion. Although their tracks across Racetrack Playa – a dry lake bed in Death Valley – have been observed and studied since the early 1900s, no one had ever seen the stones in motion … until now. What’s more, the researchers who captured this video say they now know what causes the stones to move.

Lava at Iceland volcano, with what’s left of Hurricane Cristobal

UPDATE SEPTEMBER 1, 2014 A considerable eruption occurred this weekend along the fissure that stretches to the northeast from Iceland’s Bárðarbunga volcano, currently the most-watched volcano in the world. The eruption was up to 50 times bigger than what occurred on Friday, August 29. GlacierHub reports:

At the Holuhraun lava field, lava has been erupting since Sunday morning. These lava fountains reach more than 50 meters high. Though they are dramatic, they do not release ash that would interfere with aviation. This activity is about five kilometers from Dyngjujökull Glacier. If the fissure opens under the glacier, floods might result.

This date in science: Pioneer 11 swept past Saturn

Image credit:  NASA/Ames

Image credit: NASA/Ames

September 1, 1979. On this date, NASA’s Pioneer 11 came within 13,000 miles (21,000 kilometers) of Saturn, making it the first spacecraft ever to sweep closely past that place. The spacecraft found a new ring for Saturn – now called the “F” ring – and also a new moon, Epimetheus. There were two Pioneer spacecraft. They were used to investigate Saturn’s rings and determine if a trajectory through the rings was safe for the upcoming Voyager visits. They paved the way for the even-more-sophisticated Voyager spacecraft, which were launched in 1977.

Fav photos of last night’s moon, Saturn and Mars

Vegastar Carpentier in France used a telescope to capture this view of Saturn (above) and the moon.

Vegastar Carpentier in France used a telescope to capture this view of Saturn (above) and the moon.

Did you see the moon near the planets Saturn and Mars Sunday evening? Thanks to all EarthSky friends who captured and shared these beautiful images.

Waxing moon moves past Mars and Saturn, nears star Antares

2014-sept-1-antares-mars-moon-saturn-night-sky-chart

The wide waxing crescent moon has moved eastward of the planets Mars and Saturn on the sky’s dome, and is now heading for Antares, the brightest star in the constellation Scorpius the Scorpion. The name Antares is Greek for “like Ares,” probably because the color of this star resembles that of its namesake planet, the Greek Ares or the Roman Mars.

What’s the birthstone for September?

The Logan Sapphire Brooch, the second largest sapphire known (at 422.99 carats), is on display at the National Museum of Natural History in Washington, D.C. Image Credit: Andrew Bossi

The Logan Sapphire Brooch, the second largest sapphire known (at 422.99 carats), is on display at the National Museum of Natural History in Washington, D.C. Image Credit: Andrew Bossi

Happy birthday to all you September babies!

Your birthstone, the sapphire, was said to represent the purity of the soul.

Late August and September 2014 guide to the five visible planets

Skywatcher, by Predrag Agatonovic.

Skywatcher, by Predrag Agatonovic.

Mars and Saturn appear at nightfall. Watch for them near the moon on August 31 and September 1. From southerly latitudes, you can also view Mercury near the sunset horizon. The morning planets are Jupiter and Venus.

Spectacular moon, Mars and Saturn at nightfall August 31

GregDiesel Landscape Photography wrote,

Last night’s view of the planets and moon, from GregDiesel Landscape Photography.

You won’t want to miss the beautiful celestial attraction on the evening of August 31, as the rather wide waxing crescent moon, and the planets Mars and Saturn all bunch up together in the southwest sky as darkness falls. Take a stroll with a loved one, or family and friends, to see all these worlds lighting up starry heavens first thing at nightfall.

Moon east of Spica, west of 2 planets at nightfall August 30

Moon moving toward Mars and Saturn on August 30, joins up with Mars and Saturn on August 31 and moves on toward Antares on September 1

Moon moving toward Mars and Saturn on August 30, joins up with Mars and Saturn on August 31 and moves on toward Antares on September 1.

As darkness falls around the world on August 30, look for the star Spica to the west of tonight’s waxing crescent moon. Planets Mars and Saturn are to the east of tonight’s moon. Remember, west is in the direction of sunset.

Everything you need to know: zodiacal light or false dawn

The zodiacal light – or false dawn – is an eerie light extending up from the eastern horizon, before sunrise, in autumn. You might also see it in the west after sunset, in springtime, in which case it’s called the false dusk. The light looks like a hazy pyramid of light extending up from the horizon. Follow the links inside to learn more about the zodiacal light.