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Image Credit: Arenamontanus
Science Wire | Jul 21, 2014

What exactly is twilight?

Twilight is the time of day between daylight and darkness. Astronomers, the experts on nighttime, recognize three kinds of twilight.

Expect high tides around Jan. 1 and 30, 2014
FAQs | Jul 20, 2014

What is a supermoon?

The year 2014 has a total of five supermoons. They are the two new moons of January, and the full moons of July, August and September. Next supermoon: August 10.

Stars Eltanin and Rastaban, near bright star Vega
Tonight | Jul 16, 2014

Eltanin and Rastaban are the Dragon’s eyes

On summer nights, two famous stars shine down from high in the northern sky. Eltanin and Rastaban represent the fiery Eyes of the constellation Draco the Dragon.

Skywatcher, by Predrag Agatonovic.
Tonight | Jul 14, 2014

July 2014 guide to the five visible planets

By mid-July, Jupiter is gone. As darkness falls, Mars and star Spica are closest together for 2014, with Saturn nearby. Venus and Mercury east before dawn.

Steve Pitstick of Pitstick Farms in northern Illinois caught these classic prairie storm clouds on Monday, June 30.  Used with permission.  Thank you, Steve.
Today's Image | Jul 02, 2014

Northern Illinois storm clouds on June 30

A farmer captured this photo of a serious storm sweeping through northern Illinois on Monday, June 30.

Noctilucent clouds, Estonia. Image credit: Martin Koitmä.
Blogs | Jun 23, 2014

The secrets of night-shining clouds

In twilight in the summer months, at high latitudes, you might see glowing clouds in a dark night sky. They are called noctilucent or “night-shining” clouds.

Rastaban and Eltanin represent the Dragon's Eyes.
Tonight | Jun 18, 2014

Dragon’s Eyes in the northeast on June evenings

Look in the northeast on these June evenings – near the star Vega. You’ll see Rastaban and Eltanin, two stars that are bright and close together.

Moon photos via Manuel Castillo Vela.
FAQs | Jun 16, 2014

How much of the moon can we see from Earth?

We see only 50% of the moon’s surface at one time. Even so, over time, lunar libration lets careful observers peek at a tiny portion of the moon’s far side.

Photo by Jared Rackley
Blogs | Jun 04, 2014

Kansas had a heat burst on the night of June 3-4

For a few hours around midnight, in Kansas, temperatures suddenly shot up by 10 degrees F. Meteorologists call it a heat burst. Read how it happens.

Possibly habitable environs
Braided fluvial channels (inset) emerge from the edge of glacial deposits roughly 210 million years old on the martian volcano Arsia Mons, nearly twice as high as Mount Everest. (Colors indicate elevation.) Image credit: NASA/Goddard Space Flight Center/Arizona State University/Brown University
Science Wire | May 28, 2014

Habitable environment on Martian volcano?

A volcano erupting under an immense glacier would have created large lakes of liquid water on Mars in the relatively recent past. And where there’s water, there’s the possibility of life.

209P/LINEAR May 21, 2014 by Bareket Obs
Blogs | May 22, 2014

Everything you need to know: Camelopardalids could be the best meteor shower this year

North America is predicted to have the best view of a possible new meteor shower from Comet 209P/LINEAR Friday night through Saturday morning (May 23-24, 2014). The Camelopardalids, coming up!

Areas in red and yellow, stay weather aware today.
Blogs | May 11, 2014

Stormy Mother’s Day 2014 for most of United States

Chance for significant severe weather is possible across the Plains on Mother’s Day. Strong tornadoes and large hail possible.

Virgourania
Tonight | May 11, 2014

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 – by late April and early May.

Via moonsmuses.com
FAQs | May 01, 2014

Why do we celebrate May Day?

Happy May Day! A few words about this annual celebration, whose roots are in astronomy.

April 27 tornado Baxter Springs, KS via @41ActionNews
Blogs | Apr 28, 2014

Severe weather batters U.S. Central Plains

After a slow start to severe weather season in 2014, Sunday brought storms to the U.S. Central Plains. Monday through Wednesday, the system will move into the U.S. Southeast.

This is Manann Mclir, the mythical Celtic god of the sea overlooking Lough Foyle in Northern Ireland.  The Milky Way galaxy is rising above the statue's arms in all its glory.  Glenn Miles Photography posted this one at EarthSky Facebook, in celebration of International Dark Sky Week, April 20-26, 2014.  Visit Glenn Miles Photography.
Today's Image | Apr 23, 2014

An ancient sea god under the Milky Way

A mythical Celtic god of the sea and the edgewise view into our own Milky Way galaxy, as captured by Glenn Miles Photography in Northern Ireland.

Image credit: NASA
Science Wire | Mar 27, 2014

View from space: Washington landslide

Before and after satellite images of the March 22 landslide near Oso, Washington

Star trail from March 21, 2014 by Ken Christison.
FAQs | Mar 25, 2014

What are star trails, and how can I capture them?

As Earth spins under the sky, the stars appear to move. When a camera captures that movement, that’s called a star trail. Plus … an astrophotographer explains how he does it.

Spring 2014 by Brian Abeling in Iowa
Mar 19, 2014

Photos from friends: Signs of spring

No matter what the weather where you are, enjoy these photos from EarthSky friends on Facebook and G+. Signs of spring 2014!

Image credit: Wikipedia
Tonight | Mar 07, 2014

Cancer? Here’s your constellation

Looking for the constellation Cancer? How to find it here. Plus Cancer’s place in sky history, lore and science.

Image credit: David Reed.
Blogs | Feb 24, 2014

Discovery of one new butterfly species leads to another

Just when scientists thought that all butterfly species in the eastern U.S. were identified, researchers stumbled across not one, but two new species, right under their noses.

Image credit: NASA/SAO/CXC
Tonight | Feb 03, 2014

How astronomers learn the masses of double stars

For astronomers, a binary or double star is a gift from the heavens. Astronomers observe these stars to find telltale clues to each star’s mass.

Satellite imagery on January 18, 2014 over Australia showing this "landcane". Image Credit: NASA
Blogs | Jan 25, 2014

A landcane over Australia

It’s like a hurricane, but it’s over land. These systems are not uncommon in Australia, and, last weekend, conditions were ripe for one.

Image via Ethan Siegel, Simon Swordy, NASA
FAQs | Jan 17, 2014

What is radiocarbon dating?

Unstable carbon-14 gradually decays to carbon-12 at a steady rate. Scientists measure the ratio of these carbon isotopes to determine how long ago things lived.

Aurora via Geir Inge Bushmann.
Blogs | Videos | Jan 09, 2014

Expect northern lights on January 9-10

2014 unleashed its first X-flare of 2014 on January 7. Space weather experts are calling for a good display of auroras.

Abell 1689 and distant galaxies
Science Wire | Jan 08, 2014

Smallest, faintest, most numerous galaxies seen yet in distant universe

Normally these remote galaxies would be too faint to see, even with the Hubble Space Telescope. Astronomers used a bizarre trick of nature to photograph them.

View larger. | Winter light image by Jan Inge Larsen in northern Norway.
Today's Image | Jan 08, 2014

Winter sun returns to Earth’s far north

The solstice is behind us. At high northern latitudes, sunlight is returning only briefly each day or casts an eerie twilight glow.

Science Wire | Jan 07, 2014

First gamma-ray study of a gravitational lens

The work could provide insights into the workings of black-hole jets and help us understand the rate of the expansion of the universe.

About three or four times a year, the new or full moon coincides closely in time with the perigee of the moon—the point when the moon is closest to the Earth. These occurrences are often called 'perigean spring tides.' The difference between ‘perigean spring tide’ and normal tidal ranges for all areas of the coast is small. In most cases, the difference is only a couple of inches above normal spring tides.  Image and caption via NOAA.
Today's Image | Jan 01, 2014

Extra high tides today

This new moon at the New Year is also one of the closest moons of the year. The close, new moon will cause tides to be higher than usual.

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Blogs | Dec 31, 2013

Wet weather may have helped to quell 2013 wildfire season

The amount of U.S. land burned by wildfires during 2013 was 41% lower than the 10-year average, according to preliminary estimates.

Venus on Dec. 29, 2013 by Mary C. Cox
Blogs | Photos | Dec 30, 2013

As 2014 begins, Venus a thin crescent in bright twilight

Venus is beautiful now! Just don’t wait too many days to look for it. It’ll soon disappear in the glare of sunset.

Tornado in Shoal Creek Valley, Alabama on April 27, 2011.
Science Wire | Dec 30, 2013

Use of media can save lives in bad storms

A new study shows that the risk of injury from tornados and severe storms can be reduced significantly with the use of certain media.

Analemma at 7 a.m. from January 18, 2013 to December 22, 2013.   Composed by Masayuki Shiraishi in Kumagaya, Saitama, Japan.   Used with permission and thanks.
Today's Image | Dec 30, 2013

Analemma 2013

If you photographed the sun at the same time each day – subtracting an hour as needed for Daylight Saving Time – the resulting figure-8 would be an analemma.

Earthrise via Apollo 8 astronauts in 1968
Blogs | Videos | Dec 24, 2013

Video: New earthrise visualization lets you experience it

A new visualization of events leading to one of the iconic photographs of the 20th century – Earth rising over the moon.

See full size | Comet ISON, imaged by longtime amateur astrophotograper Damian Peach in the U.K. He used a 4-inch f/5 telescope for 12 minutes of combined exposures on November 15th. Credit: Damian Peach / SkyandTelescope.com
Science Wire | Nov 20, 2013

Comet ISON brightening fast as its moment of truth nears

“We might witness a nice, long-tailed comet visible to the naked eye that will leave millions of people with fond memories for a lifetime, or maybe it will be a small comet for sky hunters using binoculars and a good map of its position. Or it might yet break up and vanish.” – Alan MacRobert

Image credit: CIMSS
Blogs | Photos | Nov 09, 2013

Incredible images and video of Super Typhoon Haiyan

Death toll is rising as reports trickle in from storm-damaged areas. Video and images here of Super Typhoon Haiyan.

“Basically, the brain is acting like a detective,” says Alexander Maier. “It is responding to cues in the environment and making its best guesses about how they fit together. In the case of these illusions, however, it comes to an incorrect conclusion.” (Credit: Fibonacci via Wikimedia Commons)
Science Wire | Oct 04, 2013

Which neurons fire when this image tricks your brain?

Scientists have pinpointed the brain region responsible for “illusory contours”—when you perceive imaginary shapes and surfaces against a fragmented background.

"Heat map" September 27 fireball sightings, via American Meteor Society.
Blogs | Sep 28, 2013

U.S. sees another bright fireball on September 27

September 2013 has been busy for sightings of bright fireballs. The one at 11:33 p.m. local time on September 27 was the 14th fireball sighting in the U.S. in September.

Image credit: P.Y. Huang, S. Kurasch et al.
Science Wire | Sep 12, 2013

World’s thinnest glass is just two atoms thick

The world’s thinnest glass is just a molecule thick, a serendipitous discovery by scientists, recorded for posterity in the Guinness Book of World Records.

Capricorn-Large
Tonight | Sep 06, 2013

Capricornus? Here’s your constellation

The constellation Capricornus the Sea-goat. How to see it, and a word about its mythology.

Phobos, via Viking 1.  Image Credit:  NASA
Blogs | This Date in Science | Aug 17, 2013

This date in science: Asaph Hall discovers 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?

Image credit: NASA/JPL/Ted Stryk.
Science Wire | Aug 08, 2013

If we landed on Jupiter’s moon Europa, what would we want to know?

So far, scientists have seen a fractured, ice-covered world with tantalizing signs of a liquid water ocean – a possible home for microbial life – under its surface.

fires-in-Siberia
Science Wire | Aug 07, 2013

Unusual heat wave intensifies Siberian wildfires

A surge of fire activity in northern Siberia, caused in part by high temperatures.

gas_cloud
Blogs | Jul 17, 2013

A gas cloud is sweeping past the Milky Way’s central black hole

Astronomers are observing the “noodle effect” as the black hole’s powerful gravity stretches and elongates the cloud.

couple drinking soda
Science Wire | May 28, 2013

Soda and illegal drugs cause similar damage to teeth

You may be shocked to learn that drinking large quantities of your favorite carbonated soda could be as damaging to your teeth as methamphetamine and crack cocaine use.

cancer cells
Science Wire | May 21, 2013

Scientists develop new tumor-killer

Scientists from Nanyang Technological University (NTU) and Lund University, Sweden, have bioengineered a novel molecule which has been proven to successfully kill tumor cells.

Upper level low responsible for the chilly weather across the Southeast on May 4, 2013. Image Credit: NOAA
Blogs | May 08, 2013

Chilly start to May in U.S. Southeast

Temperatures have been well below average for the Southeast United States for the first half of May 2013. Here’s why.

UGA researchers.  Image via Minh Phan.
Blogs | Apr 27, 2013

Social media used to study April 27, 2011 tornadoes in U.S. Southeast

University of Georgia researchers used a Facebook page to determine the trajectories of tornado debris.

Bushcricket
Science Wire | Apr 05, 2013

Ultrasonic sounds of the rainforest

New research aimed at developing ultrasonic microphones with insect-like sensitivity will continue in the rainforests of Colombia and Ecuador.

Image credit: darksky.org
Blogs | Mar 28, 2013

Death Valley designated as an International Dark Sky Park

On February 20, 2013, Death Valley National Park earned designation as an International Dark Sky Park for its pristine views of the starry nighttime sky.

Wisdom's new chick on March 5, 2013.  Photo via USFWS
Blogs | Mar 12, 2013

Oldest known albatross Wisdom hatches a new chick

At 62, the Laysan albatross Wisdom is one of the oldest wild birds known to be living in the world today. Yes, her new chick is adorable.

j_holliman image tornado mississippi
Blogs | Feb 10, 2013

Large tornado hits Hattiesburg, Mississippi

Amazing pictures and video from Hattiesburg, Mississippi as a large tornado strikes the city on February 10, 2013.

Just one big field of brotherly love.  Image via Kelly
Blogs | Feb 04, 2013

Dogs do it. Dolphins do it. Now corn, too, displays altruism.

Researchers studying corn seeds have found evidence that full “siblings” preferentially feed each other. They describe this behavior as altruism among corn.

Image Credit: Nicholas_T
Blogs | Jan 31, 2013

Stormy weather is no match for microbes

Hearty microorganisms float in the harsh air of hailstorms and hurricanes.

Artist's impression of the gas and dust disk around the young star TW Hydrae. New measurements using the Herschel space telescope have shown that the mass of the disk is greater than previously thought. Image credit: Axel M. Quetz (MPIA)
Science Wire | Jan 30, 2013

There’s more to astronomers’ favorite planetary nursery than previously thought

Astronomers have used a new method to determine the mass of the planetary nursery around the star TW Hydrae.At a distance of merely 176 light-years from Earth, this is the closest star that is currently forming new planets.

Image credit: Tatiana Makotra/Shutterstock
Science Wire | Oct 29, 2012

New study sheds light on how and when vision evolved

A new study used computer modelling to shed light on the origin of sight in animals, including humans.

Aurora from space on October 8, 2012 via NASA
Blogs | Oct 10, 2012

View from space: Aurora stretching across Quebec and Ontario on October 8

Orbiting satellite acquired view of an aurora, seen from above, on October 8, 2012. These northern lights resulted from a storm on the sun several days earlier.

Photo credit: Jussarian
Blogs | Sep 14, 2012

Where are the hottest places on Earth?

“Where’s the hottest place on Earth” is a contentious issue. Some contenders: Iran’s Lut Desert, China’s Turpan Basin and the badlands in Queensland, Australia.

682715main_isaac_night_800-600
Blogs | Sep 06, 2012

A look back at Hurricane Isaac

As of now, it appears that Isaac caused the deaths of nearly 40 people and will result in at least $3 billion in damages.

See complete map below
Blogs | Aug 21, 2012

July 2012 was fourth-warmest July globally since 1880

July 2012 was the fourth straight month in which the Northern Hemisphere set a new monthly land temperature record. It was the fourth-warmest July globally.

Sunspot grouping 1520 and July 12 X-flare.
Blogs | Jul 12, 2012

X-flare from giant sunspot group 1520

Giant sunspot group 1520 – which spans about 10 Earth diameters on the sun’s surface – emitted an X-flare on July 12 at 1653 UTC.

Arctic sea ice June 2002 versus June 2012.
Blogs | Jun 20, 2012

As summer 2012 begins, Arctic ice is melting fast

In 2007, we saw the smallest Arctic summertime ice extent since record keeping began. As summer 2012 begins, ice is melting faster now than at this same time in 2007.

The remains of Joplin High School one year after the deadly EF-5 tornado pushed through the city. Image Credit: Daniel Dix
Blogs | May 22, 2012

One-year anniversary of Joplin, Missouri tornado tragedy

Joplin tornado of May 22, 2011 was deadliest single U.S. tornado since 1950 and costliest tornado in world history. See videos. Learn how Joplin is rebuilding.

Photo credit: Anne Froehlich
Blogs | Apr 16, 2012

More emperor penguin colonies in Antarctica

Good news for penguin lovers! New satellite images show that there are twice as many emperor penguins in Antarctica than previously thought.

Tornados in Texas April 3, 2012. Image Credit: NWS
Blogs | Apr 05, 2012

Recap and videos of April 3, 2012 tornadoes in Texas

At least 11 confirmed tornadoes struck the Dallas-Fort Worth area on April 3, causing damage but no deaths. Here’s what’s known now, plus the best videos.

10-degree Map Centered at 10°N,125°E
Blogs | Feb 06, 2012

At least 15 dead, many missing, after February 6 Philippines earthquake

A 6.7 magnitude earthquake rocked the Philippines on February 6, 2012 killing at least 15 people, with many still missing.

LRO image of Apollo 17 site. Image credit: NASA/GSFC/ASU.
Blogs | Jan 08, 2012

Look for alien artifacts on moon, says renowned scientist

If extra-terrestials visited the moon, they may have left tell-tale signs. It’s worth a look, says a leading scientist, and won’t cost much.

Sunset in early fall making the entire landscape appear red. Image Credit: Matt Daniel
Blogs | Dec 16, 2011

Beautiful sunrises and sunsets!

Favorite pics of sunrises and sunsets – with an explanation of why they’re so beautiful! Post your sunrise and sunset images on EarthSky’s Facebook page.

celegans_2011_1
Blogs | Nov 30, 2011

Tiny worms might help humans get to Mars

While in space, 12 generations of worms were found to reproduce and develop from egg to adulthood no differently than they would on Earth.

Pecan pie via Wikimedia Commons
Blogs | Nov 23, 2011

How your brain cells might be sabotaging your diet

Our brain cells munch on themselves, to keep the body from starving. A new study sheds light on the role this plays in regulating appetite.

Robots that can human expressions
Blogs | Nov 20, 2011

EarthSky 22: Robots with human faces

Featured this week, lifelike robots – plus lakes on Jupiter’s moon and an eclipse of the midnight sun. Song of the week from Ocote Soul Sound.

Image Credit: Southwest Research Institute
Blogs | Nov 14, 2011

Was a fifth gas giant ejected from our solar system?

Earth might have been spared from a collision with Mars or Venus by the process in which a fifth giant world was ejected from our solar system.

haboob in Lubbock, TX
Blogs | Oct 18, 2011

Massive dust storm hits Lubbock, Texas

A haboob – an enormous dust storm – swept through parts of Lubbock, Texas on the evening of Monday, October 17, 2011.

Image Credit: IvanWalsh.com
Blogs | Sep 14, 2011

Fish farms less harmful than thought, says study

Coastal fish farms seem to do less harm to nearby plants and animals than previously believed, a new study reveals.

Smoke over Austin at midday, September 7, 2011.
Blogs | Sep 07, 2011

Texas wildfires still burning as winds die down

The largest of the Texas fires – the Bastrop fire near Austin in Central Texas – is said to be 30 percent contained today.

Visible satellite  imagery of tropical storm Irene.  Image Credit:  National Hurricane Center
Blogs | Aug 28, 2011

Where is Irene now?

UPDATE: Sunday, August 28, 5:40 p.m. EDT (21:40 UTC). Tropical Storm Irene has been gradually weakening and is beginning to lose tropical characteristics.

Image Credit: Western Arctic National Parklands
Blogs | Jul 28, 2011

After 10,000 year absence, wildfires have returned to Arctic tundra

The huge stock of carbon contained in tundra could increase atmospheric CO2 drastically, when released by a fire.

Tropical storm Arlene forms in Gulf of Mexico June 27, 2011.
Blogs | Jun 29, 2011

Watch clouds gather to form tropical storm Arlene

Watch a video that shows tropical storm Arlene as it forms in the Gulf of Mexico on June 27, 2011.

Image Credit: Crazy Creatures
Blogs | Jun 29, 2011

Loggerhead turtles’ movements predictable, says study

A ten-year study shows that loggerhead turtles go back to the same spots year after year.

Image Credit: NASA, ESA, et al
Blogs | Jun 27, 2011

In early universe, galaxies were awake or asleep, says study

Astronomers captured light from 40,000 galaxies and discovered that even in the early universe, galaxies were either awake or asleep.

girl_child_school_student
Blogs | Jun 19, 2011

Why are 160 million girls missing from Asia?

Growing scarcity of girls and women has tilted the balance of the sexes and the rich and poor in nations where “gendercide” is practiced on a large scale.

Photo credit: cybaea
Blogs | Jun 16, 2011

Two types of perception linked in surprising way

The mind is a great statistician, say psychologists studying two types of perception.

facebook_map_small
Blogs | Dec 14, 2010

Facebook map of the world

This Facebook map of the world shows the connections between about 10 million friends.

gemenids_meteor_shower_300
Blogs | Nov 08, 2010

EarthSky 22 Minutes: November 8, 2010

November meteor showers, a frozen zoo, butterfly medicine, a Bill of Rights for aliens – plus some great music – all this week on EarthSky 22.