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Comet Halley, photographed in 1986, via NASA.

Today in science: Edmond Halley

He’s the astronomer for whom Halley’s Comet is named. It was the first comet ever predicted to return.


Today in science: Launch of Sputnik

Sputnik’s unassuming beep ushered in the Space Age. Hear it here.

Image via rapgenius.com

Today in science: E=mc2

Mass and energy are interchangeable.

First view of Earth from the moon, courtesy NASA/Lunar Orbiter 1.

Today in science: Earth from the moon

First photo of Earth from the moon, released it in 1966. Later, NASA used modern digital technology to restore the photo, revealing more detail.

Phobos, via Viking 1.  Image Credit:  NASA

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?

View full image. | First photograph ever taken from surface of Mars, by the Viking 1 lander shortly after it touched down on July 20, 1976. Image via NASA.

Today in science: 1st Mars landing

40th anniversary of the first fully successful soft landing on Mars’ surface, by the Viking 1 spacecraft. First images from Mars’ surface, here.

The world watched on television as Neil Armstrong took the first steps on the moon's surface on July 20, 1969.  It was the first time humans walked another world.  As he stepped onto the lunar surface, Armstrong said, "That is one small step for [a] man, one giant leap for mankind."

Today in science: 1st footsteps on moon

Today is the 47th anniversary of humanity’s historic first steps on the moon. The story in pictures, here.

Via  NASA/JPL/SSI/CICLOPS / Mother Jones

Today in science: The day Earth smiled

Anniversary of 3rd-ever image of Earth from the outer solar system, acquired by the great Cassini spacecraft, as we Earth citizens cast our thoughts spaceward.

Fallen trees at Tunguska.  This image is from 1927, when Russian scientists were finally able to get to the scene.  Photograph from the Soviet Academy of Science 1927 expedition led by Leonid Kulik.

Today in science: The Tunguska explosion

On June 30, 1908, an explosion over Siberia killed reindeer and flattened trees. But no crater was ever found. It may have been a small asteroid.

Nakhla meteorite specimen at the American Museum of Natural History, NY. Nakhla fell in Egypt in 1911.

Today in science: Egypt’s first meteorite

It was the first meteorite in the Egyptian record. Years after the event, scientists concluded through various tests that it came all the way from Mars.

Crowd watches Apollo 11 launch on July 16, 1969

Today in science: Kennedy’s moon speech

On May 25, 1961, President John F. Kennedy gave a stirring speech to a joint session of Congress declaring his intention to land humans on the moon with a decade.

Neil Armstrong, July 20, 1969

Today in science: Neil Armstrong’s close call

On May 6, 1968 – more than a year before his famous first moonwalk – Neil Armstrong narrowly escaped disaster while training in the Lunar Landing Research Vehicle.

Jan Oort. Copyright Leiden Observatory. Used with permission.

This date in science: Jan Oort’s birthday

Visualize a vast reservoir of icy comets on the outskirts of our solar system. That’s what Jan Oort did in 1950, and why the Oort Cloud bears his name.

Comet Hale-Bopp with its prominent dust (white) and plasma (blue) tails. Photo via E. Kolmhofer, H. Raab; Johannes-Kepler-Observatory, Linz, Austria.

This date in science: Comet Hale-Bopp

The Southern Hemisphere has seen magnificent comets in recent years. But the last widely seen comet for the Northern Hemisphere was Hale-Bopp in 1996-97.


This date in science: Einstein’s birthday

While capping off the science of previous centuries, Albert Einstein changed our notions of space, time and matter … and launched modern physics.

"Let’s go! (Poyekhali!)" On 12 April 1961, Yuri Gagarin became the first human to travel into space, launched into orbit on the Vostok 3KA-3 spacecraft (Vostok 1).

Image via ESA.

This date in science: Yuri Gagarin’s birthday

He was a Russian Soviet pilot and the first human to travel to space, in 1961. Later, he became one of the world’s true heroes …


This date in science: Closest supernova since 1604

Awesome images of Supernova 1987A, a colossal stellar explosion. Plus insights gained from study in the years since then.

John Glenn and Friendship 7

This date in science: John Glenn first American to orbit Earth

On February 20, 1962, John Glenn became the first American to orbit the Earth. He made three turns around the planet before returning safely.

Breaking through the crystal spheres

This date in science: Happy birthday, Nicolaus Copernicus

Copernicus broke open the medieval idea of an enclosed, Earth-centered universe. He set the stage for all of modern astronomy.

Portrait, attributed to Murillo, of Galileo gazing at the words 'E pur si muove' (not legible in this image) scratched on the wall of his prison cell. Image via Wikimedia Commons.

This date in science: Galileo’s birthday

Happy 452nd birthday to one of the first modern scientists, Galileo. With the aid of an early telescope, he helped remove Earth from the center of the universe.