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When is the next leap year?

If there were no leap years, eventually February would be a summer month for the Northern Hemisphere. 2018 isn’t a leap year, but 2020 will be.

Top 10 reasons we fall in love

On this Valentine’s Day 2018, what the world of science suggests about the mystery we call love.

Solstice tale of two cities

December solstice sunrise comes at the same time for St. Augustine, Florida and New York City. But St. Augustine has an hour more of daylight than New York. Here’s why.

A Carolina chickadee with a juicy caterpillar. Photo courtesy of Desiree Narango and Doug Tallamy.

Want birds in your yard? Plant native trees

A recently published study confirms that native trees are most effective in hosting caterpillars, an important food for birds.

Happy Friday the 13th

When a common year of 365 days starts on a Sunday, as it did this year, 2 Friday the 13ths are inevitable. The 1st one was in January and the 2nd in October.

In 2017, China’s Mid-Autumn Festival on October 4

The Mid-Autumn Festival or Moon Festival features the beautiful idea that we all see the same moon.

Largest-ever Gulf of Mexico dead zone

For 32 years, scientists have tracked the oxygen-depleted waters that appear each summer in the Gulf of Mexico. This year’s dead zone is the biggest yet.

Solar eclipse marked beginning of Iroquois Confederacy

A total solar eclipse of August 22, 1142 may have coincided with the birth of the Iroquois Confederacy, oldest democracy in North America and possibly on Earth.

Video: Moon hoax not

SG Collins explains why the Apollo moon landings on the moon in the late 1960s and early ’70s couldn’t have been faked.

Today in science: Bingham Canyon landslide

On April 10, 2013, one of the largest non-volcanic landslides in the history of North America took place at the Bingham Canyon mine in Utah.

A Chinese perspective on spring

In Chinese thought, spring is associated with the direction east, the sunrise direction as Earth spins us toward the beginning of each new day.

How many eclipses in 1 calendar year?

Every calendar year has at least 4, but 5, 6 or even 7 eclipses are also possible. Why don’t we see them all?

What is retrograde motion?

Retrograde motion of Jupiter or Mars or Saturn in our sky is an illusion, caused by Earth’s passing these slower-moving outer worlds. But there’s a real retrograde motion, too.

Today in science: Quasar mystery solved

In 1963, Maarten Schmidt suddenly realized that quasars are exceedingly distant and unimaginably luminous. His revelation changed our notion of what the universe is like.

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.

A front view of Lucy, based on a reconstruction by paleoartist John Gurche. Image credit: Smithsonian Institution Human Origins Initiative. http://humanorigins.si.edu/australopithecus-afarensis-lucy-adult-female-reconstruction-base-al-288-1-artist-john-gurche-front

Human ancestor Lucy a tree climber

Lucy lived 3.18 million years ago in what’s now Ethiopia. An analysis of high-resolution CT scans of her fossilized skeleton shows she was equipped for climbing trees.

Last quarter moon 3rd of 4 this season

Usually there are only 3 last quarter moons in a season. The November 21, 2016 last quarter moon, though, counts as the 3rd of four.

Today in science: An island is born

On November 14 1963, crew aboard a trawler sailing near Iceland spotted a column of smoke rising from the sea surface. A new island, Surtsey, was being born.

Animal shapes in clouds, and other pareidolia

Seeing animals in clouds, or a face in the moon, are examples of pareidolia. Look here for photos to test your own ability to see things that aren’t there.

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?