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Comet Lovejoy near star Polaris

View larger. | Comet Lovejoy on May 22, 2015.  The comet is the brilliant green dot near the center of the photo.  At the upper right of the photo is the star Polaris, aka the North Star.  Photo by Stuart Atkinson.  Used with permission.

May 22 photo of Comet Lovejoy (green dot, center of photo) and star Polaris (bright, upper right of photo) by Stuart Atkinson. Used with permission.

Here is a grand photo of Comet C/2014 Q2 (Lovejoy), which is now in the northern sky, not far from the North Star, Polaris. On May 26, 2015, Stuart Atkinson posted this photo and wrote a great article about how to spot the comet now, at the blog of the Society for Popular Astronomy. Details inside.

Which phase of moon best for stargazing?

crescent-moon-watching

We got this question:

Which phase of the moon would be best for stargazing, and why?

And the answer is … it depends on what you want to do. Some people enjoy watching the moon itself, as it waxes and wanes in our sky. On the other hand, people using telescopes avoid the moon because its glare interferes with deep-sky objects.

What is a coronal mass ejection or CME?

Aug 2012 CME

Aug 2012 CME

Every so often, the sun burps with the power of 20 million nuclear bombs.  These hiccups are known as coronal mass ejections (CMEs)—powerful eruptions near the surface of the sun driven by kinks in the solar magnetic field.  The resulting shocks ripple through the solar system and can interrupt satellites and power grids on Earth. During a CME, enormous bubbles of superheated gas—called plasma—are ejected from the sun.  Over the course of several hours, one billion tons of material are lifted off the sun’s surface and accelerated to speeds of one million miles per hour.  This can happen several times a day when the sun is most active.

Sunday is Cassini’s last close sweep of Saturn’s moon Hyperion

This false-color view of Hyperion was obtained during Cassini's closest flyby of Saturn's odd, tumbling moon on Sept. 26, 2005. Image via NASA/JPL-Caltech/SSI

Cassini captured this false-color view of Hyperion during its closest flyby of Hyperion on September 26, 2005. Image via NASA/JPL-Caltech/SSI

NASA’s Cassini spacecraft will make its final close approach to Saturn’s large, odd, tumbling, irregularly shaped moon Hyperion on Sunday, May 31, 2015. The Saturn-orbiting spacecraft will pass Hyperion at a distance of about 21,000 miles (34,000 kilometers) at approximately 6:36 a.m. PDT (9:36 a.m. EDT, 1336 UTC). Mission controllers expect images from the encounter to arrive on Earth 24 to 48 hours later.

6.7-magnitude earthquake in Alaska

May 29, 2015 earthquake in the Aleutian arc.  Image via USGS

May 29, 2015 earthquake in the Aleutian arc. Image via USGS

The U.S. Geological Survey (USGS) says a 6.7-magnitude earthquake has struck off in an earthquake-prone, sparsely populated region off the southwest coast of Alaska. The quake occurred at 3 a.m. EDT (0700 UTC) Friday morning, May 29, 2015. The epicenter is approximately 70 miles (110 km) south-southeast of Ugashik – nearly 400 miles (600 km) southwest of Anchorage – with the earthquake’s center estimated at 20 miles (33 km) deep.

Moon close to Spica again on May 29

2015-may-29-spica-moon-night-sky-chart

The bright waxing gibbous moon again shines close to the star Spica on the evening of May 29. Spica’s significance comes from the fact that it’s the brightest star in the constellation Virgo, and also a key star of the Zodiac. The Zodiac consists of the rather narrow band of stars in front of which the sun, moon and planets endlessly travel.

Humans tell whales apart by their voices

North Atlantic right whle and calf, via Wikimedia Commons

North Atlantic right whle and calf, via NOAA and Wikimedia Commons

Acoustical researchers at Syracuse University in New York have learned that whales give distinctive calls, by which even humans can distinguish one whale from another.

Video: 40 hours at Ningaloo Reef

Colin Legg in Australia emailed us with word of this video, which is a 40-hour continuous time lapse at Ningaloo Reef in Coral Bay, Western Australia.

Octopus opens a jar, from the inside

More evidence – from Enoshima Aquarium in Japan – that octopuses are amazing.

New human ancestor found in Ethiopia

Lead author Yohannes Haile-Selassie of The Cleveland Museum of Natural History holds casts of the jaws of Australopithecus deyiremeda, a new human ancestor from Ethiopia.  Photo: Laura Dempsey

Lead author Yohannes Haile-Selassie of The Cleveland Museum of Natural History holds casts of the jaws of Australopithecus deyiremeda, a new human ancestor from Ethiopia. Photo: Laura Dempsey

Humans, meet your new ancestor. This new hominin species likely lived at the same time – and is believed by scientists to be a close relative to – the famous “Lucy” species first discovered in Ethiopia in 1974. That is, this species lived 3.3 to 3.5 million years ago and is thought to be a human ancestor (although it is not an identical species to Lucy, according to these scientists).