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It’s small, it’s hot, and it’s shrinking. Surprising new NASA-funded research suggests that Mercury is contracting even today, joining Earth as a tectonically active planet. Image via NASA/JHUAPL/Carnegie Institution of Washington/USGS/Arizona State University

Mercury is tectonically active, says study

New findings suggest Mercury is contracting, and might be the only other planet in the solar system to experience earthquakes – or “mercuryquakes.”

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Are we in a sixth mass extinction?

This short video puts modern extinctions in context by comparing them with Earth’s 5 previous mass extinctions.

Image via NASA

Possible water plumes spotted on Europa

Water plumes erupting on Jupiter’s moon Europa might make it easier to investigate whether life exists in the warm ocean believed to be deep beneath its icy surface.

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Why time travel isn’t possible

Why does time flow inexorably toward the future? A Berkeley physicist proposes that time is expanding because space is expanding.

This view shows Saturn's northern hemisphere in 2016, as that part of the planet nears its northern hemisphere summer solstice in May 2017. Saturn's year is nearly 30 Earth years long, and during its long time there, Cassini has observed winter and spring in the north, and summer and fall in the south. The spacecraft will complete its mission just after northern summer solstice, having observed long-term changes in the planet's winds, temperatures, clouds and chemistry. Image via NASA JPL.

Cassini begins epic final year at Saturn

The spacecraft will plunge repeatedly between Saturn and its rings, and finally execute a headlong plummet into the body of Saturn itself.

A polar bear tests the strength of thin sea ice. Image via Mario Hoppmann/imaggeo.egu.eu

Melting sea ice leaves polar bears hungry

“Sea ice really is their platform for life. They are capable of existing on land for part of the year, but the sea ice is where they obtain their main prey.”

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What if all of Earth’s ice melted?

What would Earth be like if all of its ice melted? New short video from the guys at AsapSCIENCE, featuring Bill Nye.

The image shows an area nicknamed the "Xanadu annex" by members of the Cassini radar team, earlier in the mission. Image via NASA/ JPL.

Glorious new images show Titan’s dunes

Cassini spacecraft will begin its grand finale at Saturn in 2017. This was one of Cassini’s last close flybys of Saturn’s large moon, Titan.

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Brown dwarfs hiding in plain sight

Brown dwarfs are like stars, but too small to ignite fusion in their cores and so shine as stars do. If you saw one, it wouldn’t be brown. It’d be magenta.

NASA's Juno spacecraft captured this view as it closed in on Jupiter's north pole, about two hours before closest approach on August, 27, 2016. Image via NASA/JPL-Caltech/SwRI/MSSS

Listen to Jupiter’s auroras

Plus more cool stuff from the Juno spacecraft’s August 27 closest-yet flyby of Jupiter.

The strange mountain on dwarf planet Ceres, called Ahuna Mons.

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.

ou can tell Earth and the moon’s shadows apart by their edges: Earth’s is fuzzy, while the moon’s is sharp and distinct. This is because Earth’s atmosphere absorbs some of the sun’s light, creating an ill-defined edge. On the other hand, the moon has no atmosphere, producing a crisp horizon. Image via NASA/SDO

SDO sees a double eclipse

Cool video! On September 1, the Earth-orbiting Solar Dynamics Observatory caught both Earth and the moon crossing in front of the sun.

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Fiery sunset clouds over Zimbabwe

These sunset clouds resemble the real dry season fires going on in Zimbabwe at this time of year.

he HI-SEAS mission gives people a chance to practise on Earth what life would be like on Mars. A crew member here from the 2015 mission.  Image via Flickr/University of Hawaii/HI-SEAS

After a year on (simulated) Mars

A week ago, a test crew emerged after living for a year in Mars-like conditions inside a solar-powered dome on the slopes of Hawaii’s Mauna Loa volcano.

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Wow! Yellowstone geysers time-lapse

People go to Yellowstone to see boiling geysers erupt periodically with an awesome, yet very earthly, power. See them in this new video.

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Space X explosion at Cape Canaveral

No injuries in Thursday’s explosion on a SpaceX launch pad at Cape Canaveral. But Facebook’s planned satellite is no more.

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No alien signal, says SETI astronomer

A strong signal from a sunlike star sparked speculation this week that we might – at last – have heard from an alien civilization. Now astronomers say … no.

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Photos and video of Venus and Jupiter!

August 27, 2016 was the conjunction of Jupiter and Venus. Sky’s 2 brightest planets. Closest conjunction of any 2 planets in 2016.

Image via NASA.

A new normal for Arctic sea ice?

“A decade ago, this year’s sea ice extent would have set a new record low …Now, we’re kind of used to these low levels of sea ice – it’s the new normal.”

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Way-cute googly-eyed stubby squid

It’s purple! An underwater research team spotted this guy off the coast of California.