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Virgo? Here’s your constellation

The constellation Virgo the Maiden fully returns to the early evening sky – with her feet planted on the eastern horizon – in early May.

The last of Hubble’s Frontier Fields

With a final observation of remote galaxy cluster Abell 370, the Hubble Space Telescope’s mind-stretching Frontier Fields program came to an end.

Why do we celebrate May Day?

Happy May Day! A few words about this annual celebration, which has its roots in astronomy.

Asteroid 2014 JO25 bigger than expected

It’s coming closer today than any asteroid this large since 2004. It came into view of small telescopes a few hours ago. Early radar observations indicate it’s bigger than we thought.

First-ever image of dark matter?

The scientists say their image, which combines images from more than 23,000 galaxy pairs, confirms dark matter’s existence. Will other astronomers agree?

Know the Big and Little Dippers

The Big Dipper is easy. And, once you find it, you can find the Little Dipper, too. Plus … learn how the stars of the Big Dipper are moving in space.

Lenticular clouds look like UFOs

Glorious photos of rare lenticular clouds, sometimes called UFO clouds, plus a word about how they form.

How to take great photos of star trails

When a camera captures a star’s movement across the sky, it’s called a star trail. An astrophotographer explains how he does it.

Venus as a crescent world

Photos from the EarthSky community of the planet Venus – next planet inward from Earth in orbit around the sun – in early 2017, in a crescent phase.

Cloud shadow on nearby clouds

Like all objects illuminated by sunlight, clouds cast a shadow.

Last full moon of season this weekend

March 2017 full moon is the 3rd of 3 full moons between the December solstice and March equinox. Harbinger of spring for Northern Hemisphere. Southern Hemisphere’s Harvest Moon.

What moves Death Valley’s sliding stones?

People used to think that strong winds caused the rocks to move across Death Vally’s Racetrack Playa. Turns out, it’s not.

Sliding stone, Death Valley

Here’s a beautiful image of a sliding (or sailing or slithering) stone at Death Valley’s famous Racetrack Playa. Cat Connor caught it on Christmas Day 2014.

Leo and Chinese guardian lions

An earthly lion guards the gates, while, in the sky, a celestial Lion – Leo – ascends. Astrophotographer Jeff Dai of China tells the story.

Why pandas are black and white

The giant panda’s distinct black-and-white markings have two functions: camouflage and communication, says a new study.

March 4 moon hides Aldebaran

The occultation by the moon of Aldebaran – brightest star in Taurus the Bull – was visible from North America. Great set of photos here from the EarthSky community!

Cancer? Here’s your constellation

Here’s how to find the constellation Cancer in your sky. Plus Cancer’s place in sky history, lore and science.

Storm chasers honor Bill Paxton

An amazing several-state tribute – stretching across Tornado Alley – honoring Twister star Bill Paxton, who died Sunday due to complications from heart surgery.

What is radiocarbon dating?

At a very steady rate, unstable carbon-14 gradually decays to carbon-12. The ratio of these carbon isotopes reveals the ages of some of Earth’s oldest inhabitants.

See it! Young moon, Venus, Mars

The moon has returned to the evening sky. This week, it’s sweeping past brilliant Venus and fainter Mars. Photos from the EarthSky community, here.

$40 billion a day for solar super-storms

The probability of another event like the 1859 Carrington event is – at any given time – low. But many believe it’s “almost inevitable” one will occur, eventually. A new study explores the risks.

Moon near former pole star on January 9

People in Asia will see Aldebaran pass behind the moon on this date. The rest of us will see Aldebaran in the moon’s glare. Plus … the story of Aldebaran when it was part of a double pole star.

Leap second to be added December 31

Delay those New Year’s plans. World timekeepers will add a leap second just before midnight on December 31, 2016.

Drought still grips southern California

California has dry spells, but the state hasn’t had exceptional drought since at least 2000. Now, about 20 percent of California is in exceptional drought, and many trees have died.

Mount Hekla was called Gateway to Hell

Mount Hekla is Iceland’s 3rd most active volcano. A large eruption in 1104 earned it the moniker Gateway to Hell. Is Mount Hekla overdue for another eruption?

See it! Super Hunter’s Moon 2016

Many captured the full Hunter’s Moon last night. It was also the 1st of 3 supermoons in 2016.  Thanks to all who contributed!

Day and night exactly equal at equinoxes?

On the day of the equinox, the center of the sun would set about 12 hours after rising – given a level horizon, as at sea, and no atmospheric refraction.

Supermoons and the Saros cycle

Here’s one you might not know … the intriguing relationship between supermoons and the famous 18-year Saros cycle of eclipses.

Update on Dawn mission to Ceres

The Dawn spacecraft is still orbiting Ceres. It went into an extended mission mode on July 1. Some mission highlights and current thinking, here.

Capricornus? Here’s your constellation

The constellation Capricornus the Sea-goat. How to see it, and how a sea-goat came to reside among the stars.

Today in science: A moon for Mars

American astronomer Asaph Hall discovered Phobos, one of the two Martian moons, on this date in 1877. Did he imagine how well we’d see Mars’ moons today?

Sagittarius? Here’s your constellation

You can see the constellation Sagittarius on August evenings. Look here for the lore and science of this constellation.

Humpback whales, heroes of the sea?

Humpback whales appear to rescue not just their own species, but also other whale species, seals and sea lions from attacks by killer whales.

Parakeet takeover ahead?

“Parakeets are Britain’s fastest growing bird population and are on a trajectory to global domination.”

Eltanin and Rastaban, the Dragon’s Eyes

These two famous stars shine down from the northern sky. Eltanin and Rastaban represent the fiery Eyes of the constellation Draco the Dragon.

Earth-sized aurora on Jupiter

NASA released this image as the Juno spacecraft arrived at Jupiter.

Astronomers find a baby planet

Planet K2-33b resides in a solar system in the process of being born. In human terms, if Earth were 45 years old, this planet would be just a few weeks old.

What is virga?

We’ve all seen virga, but maybe not known what it’s called. Virga is rain that evaporates before it hits the ground. Enjoy these photos!

The secrets of night-shining clouds

People at high latitudes are seeing glowing clouds in a dark night sky. They’re called noctilucent or “night-shining” clouds.

Deciphering mysterious honey bee decline

While the massive and sudden colony collapses that occurred a decade ago have abated, honey bees are still dying at troubling rates.

Airplane crosses sun’s face

While preparing on Sunday to watch today’s transit – an event Mercury crosses the face of our sun – Helio C. Vital caught an airplane doing the same.

Milky Way over Arenal Volcano in Costa Rica

“Since three years ago, we have planned to shoot this photo. We went to the zone repeatedly but every time we got nothing … until now.” – Sergio Vindas

Chernobyl all-time worst nuclear accident

The meltdown at the Chernobyl Nuclear Power Plant on April 26, 1986 exposed 572 million people to radiation. It was far worse than the 2011 Fukushima accident.

An inconspicuous comet

Many hoped Comet 252P/LINEAR would become visible to the eye. It has, but only barely. Enjoy photos from the few, the proud, who’ve captured this comet on film!

Closest new moon of 2016 on April 7

April 7 moon turns new six hours before perigee – closest point to Earth. We won’t see it, but it counts as a supermoon and will affect ocean tides.

This ancient arthropod kept its babies on a leash

Scientists have discovered a tiny 430-million-year-old sea creature – dubbed Kite Runner – that apparently dragged its offspring around on strings like kites.

Closest comet in 246 years via radar

Record-breakingly close flybys of two comets earlier this week. Radar images of one, the closest comet in 246 years. Will the other be visible to the eye?

First of year’s 6 supermoons March 9

We’ll have six supermoons in 2016. The first one is a new moon supermoon, not visible in our sky.

Moons might hold key to finding E.T. life

As the list of known planets beyond our solar system grows, the search for their moons is intensifying. Why exomoons might be key to E.T. life.

See 5 bright planets at once

First time we can see 5 planets at once since 2005. All 5 are up before dawn, still, and all 5 will remain visible until Mercury disappears in the dawn just after mid-February.