It’s all relative: Happy New Year, Neptune
NASA's Hubble Space Telescope captured this image of Neptune in late June
July 13th, 2011
10:30 AM ET

It’s all relative: Happy New Year, Neptune

It seems a lot longer, but the planet Neptune was discovered one year ago today.

You may recall hearing about Neptune when you were a child, and you may even have read about it in books from the 19th century, but the fact is it's only been a year since German astronomer Johann Galle discovered the aquamarine orb out in the hinterland of the solar system.

A Neptunian year, that is.

Galle identified the planet in September 1846. Only now has Neptune returned to the same spot in its wide orbit, taking 164.8 Earth years to complete a single circuit around the sun.

"One of the things that make it unique is it was the first planet that was discovered through mathematics," said John French, a presenter at Michigan State University's Abrams Planetarium.

Astronomers in the 19th century noticed the planet Uranus seemed to be deviating from its predicted orbital path and figured the gravity of another, unseen, planet must be tugging on it. Mathematicians Urbain Le Verrier of France and John Couch Adams of England separately calculated where that other planet must be located. Galle peered into that part of the sky and found Neptune.

Similar study of Neptune's orbit led to the discovery of the mini-planet Pluto in 1930, French said.

NASA's Hubble Space Telescope  took some birthday pictures of Neptune. They show the planet's Earth-like tilt, which means it has four seasons too - except that on Neptune, each season lasts about 41 Earth years. It's summer in Neptune's southern hemisphere right now, but vacationing there could be a challenge.

Since the planet is composed of gaseous hydrogen and methane, "there's no ground to lay your blanket on and stretch out and bake in the sun," French quipped.

Neptune is 2.8 billion miles from the sun, 30 times as far as Earth, according to NASA.

You can see Neptune with binoculars or a small telescope in the constellation Aquarius, close to the boundary with Capricorn.

It has 13 moons, including Triton , which NASA's Voyager 2 spacecraft  discovered has geysers, French noted.

"So, future vacationers can go there and watch the geysers on Triton," he said.

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Filed under: In Space • News
Scientists: Saturn moon could support life
NASA's Cassini space probe snapped this photo of jets spewing from Enceladus, one of Saturn's 53 moons.
June 24th, 2011
05:28 PM ET

Scientists: Saturn moon could support life

Where there's salt, there's water and rock, it seems. And where there's water and rock, there could be life.

NASA's Saturn-exploring Cassini spacecraft has gathered new evidence that conditions on Enceladus, one of Saturn's 53 named moons, could support life, said Dr. Carolyn Porco, director of the Cassini Imaging Central Laboratory for Operations at the Space Science Institute in Boulder, Colorado.

"On Enceladus we have conditions under the surface that we know could be enjoyed by organisms similar to types of organisms we find right here on Earth," she said Friday.

FULL STORY at CNN's This Just In

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Filed under: In Space • News
Spectacular lunar eclipse Wednesday
June 15th, 2011
03:58 PM ET

Spectacular lunar eclipse Wednesday

Sky gazers in much of the world will see a spectacular lunar eclipse Wednesday night. But if you're in North America, Greenland or Siberia, you'll have to view it virtually.

Lunar eclipses occur two to four times a year, when the sun, Earth and moon align. This one is special because the period of totality – when the moon is completely covered by Earth's shadow – will last for one hour, 40 minutes, considerably longer than usual, said David Dundee, astronomy program director at the Tellus Science Museum in Cartersville, Georgia.

"All lunar eclipses are cool, but in a total lunar eclipse, the moon turns a kind of a red color," he said. The middle of Earth's shadow isn't black, it's red, Dundee explained, because the light waves from the sun that are on the red end of the spectrum bend around the planet at just the right angle to bathe the moon in red light.

FULL STORY at CNN's This Just In

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Filed under: Eclipse • In Space
Are we there yet? Mars rover nears crater
June 10th, 2011
04:42 PM ET

Are we there yet? Mars rover nears crater

NASA's rover on Mars, Opportunity, is closing in on Endeavour crater. It has taken the rover nearly three years to travel 11 miles across the Martian terrain.

And you thought your grandpa drove slowly.

Opportunity will enter the crater at a spot named Spirit Point in honor of the rover's late partner. Spirit fell silent in March 2010, and its mission was terminated after one final attempt to communicate with it last month.

Both rovers completed their prime, three-month missions on Mars in April 2004, NASA said, but kept going (and going and going) with years of bonus work.

FULL STORY at CNN's This Just In

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Filed under: In Space
What a Babylonian laundry list says about you
June 10th, 2011
04:40 PM ET

What a Babylonian laundry list says about you

Scholars have completed a dictionary after 90 years of work. Considering the language they were working on is 4,500 years old, they made pretty good time.

The University of Chicago's Oriental Institute this week announced completion of the Chicago Assyrian Dictionary, a work begun by institute founder James Henry Breasted in 1921.

The 21-volume, 9,700-page opus identifies, explains and provides citations for the words written in cuneiform on clay tablets and carved in stone by Babylonians, Assyrians and others in Mesopotamia between 2500 B.C. and A.D. 100. The first 20 volumes were published as they were completed, but now the work is complete.

FULL STORY at CNN's This Just In

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Filed under: Human ancestors • On Earth

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