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Perseid meteors versus the supermoon

Which is brighter – Perseid fireballs or a supermoon? You’ll find out this August as the year’s biggest, brightest full moon arrives at the peak of the Perseid meteor shower.

Wildly misaligned planet-forming disks in binary star system HK Tau

Here is the double star system HK Tau, as seen in both optical and infrared.  Astronomers have discovered that the star-forming disks of this double star are oriented oddly with respect to each other.  Image via B. Saxton (NRAO/AUI/NSF); K. Stapelfeldt et al. (NASA/ESA Hubble)

Here is the double star system HK Tau, as seen in both optical and infrared. The star-forming disks of this double star system are oriented oddly with respect to mutual orbit of the two stars. Image via B. Saxton (NRAO/AUI/NSF); K. Stapelfeldt et al. (NASA/ESA Hubble)

Astronomers have contemplated planets forming in single flat disks, as in our own solar system, for decades. Misaligned planet disks in a binary star system? Weird! But now they’ve found the best example so far, in the course of conducting a survey of binary stars with the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile.

Scientists discover vast methane plumes escaping from Arctic seafloor

Mega methane event.  Image via University of Stockholm via Daily Kos.

Mega methane plume event on the Laptev Sea slope of the Arctic Ocean, at a depth of about 62 meters. Image via Daily Kos via University of Stockholm.

An international team of scientists aboard the icebreaker Oden – currently north of eastern Siberia, in the Arctic Ocean – is working primarily to measure methane emissions from the Arctic seafloor. On July 22, 2014, only a week into their voyage, the team reported “elevated methane levels, about 10 times higher than background seawater.”

Milky Way is about half as massive as Andromeda galaxy, say astronomers

An image of the Andromeda galaxy, Messier 31.  Image credit: Adam Evans

An image of the Andromeda galaxy, Messier 31. Image credit: Adam Evans

Dark matter makes up 90% of the matter in both systems, the study finds.

Forest path

View larger. | Photo: T.  Richardsen

View larger. | Photo: T. Richardsen

A misty forest path … Where does it lead? Tommy Richardsen captured this image in Sørkjosen, Troms, Northern Norway.

Constellation Scutum named for a Polish king

After the waxing crescent moon sets at late evening on Wednesday, look for one of summer’s most beautiful celestial sights. Be sure you are looking in a dark country sky, far away from the the glare of city lights. You’ll find a hazy pathway stretched across the sky. This band is the starlit trail of our own Milky Way galaxy. We in the N. Hemisphere look southward in late in the evening – toward the richest part of the Milky Way – to find a very small constellation called Scutum the Shield.

101 geysers on Enceladus, ice moon of Saturn

This view looks across the geyser basin of Saturn's moon Enceladus, along fractures spewing water vapor and ice particles into space. Cassini scientists have pinpointed the source locations of about 100 geysers and gained new insights into what powers them. Image credit: NASA/JPL-Caltech/SSI

This view looks across the geyser basin of Saturn’s moon Enceladus. What you see here are fractures spewing water vapor and ice particles into space. Cassini scientists have now pinpointed some 101 geysers on Enceladus. They believe a large underground ocean is the geysers’ dominant source. Image via NASA/JPL-Caltech/SSI

Using data from NASA’s Cassini spacecraft – which has been orbiting Saturn, weaving among its moons, since 2004 – scientists have now mapped 101 distinct geysers erupting from the surface of Enceladus, an ice world and arguably Saturn’s most fascinating moon. They’ve concluded that the only plausible source for the geysers is an underground sea now known to exist beneath Enceladus’ icy surface.

We’re in the early days of Earth’s sixth great extinction, say biologists

Photo credit: John Spooner/Flickr

Photo credit: John Spooner/Flickr

An international team of scientists cautions that the loss and decline of animals is contributing to what appears to be the early days of the planet’s sixth mass biological extinction event.

Since 1500, more than 320 terrestrial vertebrates have become extinct. Populations of the remaining species show a 25 percent average decline in abundance. The situation is similarly dire for invertebrate animal life.

Mars rover set an off-world driving distance record this week

Image credit:

Image credit:

The chart above provides a comparison of the distances driven by various wheeled vehicles on the surface of Mars and Earth’s moon. On July 27, the Opportunity rover passed 25 miles driven – an off-world driving distance record. Opportunity has gone farther than any other earthly wheeled vehicle on another world. It’s especially remarkable, NASA says, because Opportunity was intended to drive about one kilometer (.6 mile) and was never designed for distance.

Star Skat is near radiant for Delta Aquarid meteors

When you stand on a railroad track, you can see the illusion of tracks converging in the distance.  Likewise, the paths of meteors in a single meteor shower appear to converge at a point on the sky's dome.  This is the shower's radiant point.

When you stand on a railroad track, you can see the illusion of tracks converging in the distance. Likewise, the paths of meteors in a single meteor shower appear to converge at a point on the sky’s dome. This is the shower’s radiant point.

How to spot it, plus an explanation of why meteors in annual showers have radiant points.