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Perseid meteor shower kicks off! Fireballs detected this weekend

NASA cameras in New Mexico caught this Perseid fireball on July 27, 2014

NASA cameras in New Mexico caught this Perseid fireball on July 27, 2014.

NASA cameras detected some Perseid fireballs, or very bright meteors, this weekend. This favorite among meteor showers is just getting started, with Earth now entering the stream of debris left behind by Comet Swift-Tuttle. The shower typically builds gradually to a peak (this year on the mornings of August 11, 12 and 13), and NASA detected at least five Perseid fireballs over the weekend. Learn when to watch … inside.

As Comet Siding Spring approaches Mars, NASA gets ready

An illustration of the inner part of the orbit of comet C/2013 A1 Siding Spring.  On October 19, 2014, the comet will have a close pass of the planet Mars.  Its nucleus will miss Mars by about 82,000 miles (132,000 kilometers). The comet's trail of dust particles shed by the nucleus might be wide enough to reach Mars or might also miss it.   Image via NASA/JPL.

An illustration of the inner part of the orbit of comet C/2013 A1 Siding Spring. Image via NASA/JPL.

One of the most anticipated astronomical events of 2014 is the close passage of Comet C/2013 A1 Siding Spring to the planet Mars on October 19, 2014. The comet’s tiny nucleus, or core, will miss Mars by about 82,000 miles (132,000 kilometers). As comets travel through space, though, they leave behind a trail of dust particles, and this trail of debris might be wide enough to reach Mars and encounter its thin atmosphere … or might miss it, too. Follow the links inside to learn more.

Second mysterious crater reported from Yamal

Helicopters found the first crater.  Reindeer herders report a second.  Photo of first crater via Siberian Times.

Helicopters found the first crater. Reindeer herders now report a second. Photo of first crater via Siberian Times.

The Moscow Times reported this week that reindeer herders in far northern Russia have found a second mysterious giant hole. According to these unconfirmed reports, the second hole is about 30 kilometers (20 miles) away from a first large and mysterious hole in the Russian permafrost, which made a big splash in social media after the Siberian Times reported it in mid-July 2014.

Orion returns

Here is a sight many skywatchers wait for, patiently, each summertime. It’s the constellation Orion the Hunter, rising out of the dawn. Matthew Chin in Hong Kong caught this photo of the constellations Orion, Auriga and Taurus yesterday (July 26, 2014). Watch for Orion before dawn, and give yourself a seasonal marker you’ll come to love as much as autumn leaves … or the first flowers of spring.

See Ophiuchus, 13th constellation of the Zodiac, tonight

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The faint constellation Ophiuchus the Serpent Bearer appears in the southern sky at nightfall and early evening at this time of year. It descends into the southwest sky as evening deepens into late night. Ophiuchus is sometimes called the “13th” or “forgotten” constellation of the Zodiac. The sun passes in front of Ophiuchus from about November 29 to December 17. And yet no one ever says they’re born when the sun is in Ophiuchus. That’s because Ophiuchus is a constellation – not a sign – of the Zodiac.

EarthSky’s meteor shower guide for 2014

EarthSky Facebook friend Eileen Claffey caught this meteor on the night of July 25, 2014.  The time to start watching is now!  Thanks, Eileen.

EarthSky Facebook friend Eileen Claffey caught this meteor on the night of July 25, 2014. The time to start watching is now! Thanks, Eileen.

Don’t wait until August 11, 12 and 13 to watch the Perseids in 2014. The moon will be in the way. Start watching for meteors now!

As Rosetta approaches its comet, a bright ‘neck’ and hilly terrain

View larger. | Comet 67P/Churyumov–Gerasimenko .  Imaged: Sunday 20 July 2014.

View larger. | Comet 67P/Churyumov–Gerasimenko as imaged by the Rosetta spacecraft on July 20, 2014.

UPDATE July 25, 2014. Some real detail is beginning to show. This image shows the 3.5-by-4-km-sized nucleus of the comet seen closer in at a distance of 5,500 kilometers / 3,400 miles by the Rosetta Mission OSIRIS NAC camera. Surface features on the nucleus are now becoming apparent in these 100-meter resolution images. Looks like the impact crater suspected on the bulbous lobe does exist, and there appear to be some linear depressions and hills on the larger lobe. Both lobes are beginning to show hilly terrain.

Stars with cool names: Zubenelgenubi and Zubeneschamali

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On July and August evenings, try finding two stars in the constellation Libra with the coolest of all star names: Zubenelgenubi and Zubeneschamali. They’re located in between two of the sky’s brightest stars, Antares in the constellation Scorpius and Spica in the constellation Virgo. In 2014, you’ll see the golden planet Saturn shining in between these two Libra stars.

Can we find aliens by looking for their pollution?

In this artist's conception, the atmosphere of an Earth-like planet displays a brownish haze - the result of widespread pollution. New research shows that the upcoming James Webb Space Telescope potentially could detect certain pollutants, specifically CFCs, in the atmospheres of Earth-sized planets orbiting white dwarf stars. Image credit: Christine Pulliam (CfA)

In this artist’s conception, the atmosphere of an Earth-like planet displays a brownish haze – the result of widespread pollution. New research shows that the upcoming James Webb Space Telescope potentially could detect certain pollutants, specifically CFCs, in the atmospheres of Earth-sized planets orbiting white dwarf stars. Image credit: Christine Pulliam (CfA)

Maybe some extra-terrestrials pollute their planets too.

See which parts of the U.S. are losing groundwater

Image credit Chris Poulsen, National Drought Mitigation Center/University of Nebraska-Lincoln

Image credit Chris Poulsen, National Drought Mitigation Center/University of Nebraska-Lincoln

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Groundwater is the water found underground in the cracks and spaces in soil, sand and rock. Groundwater accounts for more than half of the U.S. drinking water and crop irrigation, and a source of recharge for lakes, rivers, and wetlands. It’s stored in geologic formations of soil, sand and rocks called aquifers.

This map was created using satellite data and ground-based measurements to model the relative amount of water stored in underground aquifers in the continental United States on July 7, 2014, compared to the average from 1948 to 2009.