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Are those sinkholes on Rosetta’s comet?

This close-up image shows the most active pit, known as Seth_01, observed on the surface of comet 67P/Churyumov-Gerasimenko by the Rosetta spacecraft. A new study suggests that this pit and others like it could be sinkholes, formed by a surface collapse process similar to the way these features form on Earth. Image via Vincent et al., Nature Publishing Group

Close-up of pit on comet 67P/Churyumov-Gerasimenko. This is the most active pit, known as Seth_01. A new study suggests this pit and others like it could be sinkholes. Image via Rosetta spacecraft, Vincent et al., Nature Publishing Group

Scientists announced this week that deep, almost perfectly circular pits on the surface of Comet 67P/Churyumov-Gerasimenko may be sinkholes. Sinkholes on Earth happen when a subsurface cavern collapses. On the comet, the caverns may be created by ices turning to gas, as the comet nears the sun.

Rosetta team struggles with Philae link

A view of Comet 67P/Churyumov-Gerasimenko from Rosetta, showing the spacecraft's huge solar panels. This

A view of Comet 67P/Churyumov-Gerasimenko from Rosetta, showing the spacecraft’s huge solar panels. This “selfie” was actually taken by Philae while still attached on Sep. 7, 2014. Image credit: ESA/Rosetta/Philae/CIVA

Since Philae renewed contact on June 13, the Rosetta team has been struggling to establish a stable link with the comet lander.

Leap second scheduled for June 30

Image via riaus.org

Image via riaus.org

A leap second will be added to official timekeeping on Tuesday, June 30, 2015. That means your day – and my day and everyone’s day – will officially be one second longer. Meanwhile, a proposal to dump the leap second has been deferred until October.

Next Mars mission is ESA’s ExoMars

Artist's concept the Trace Gas and Data Relay Orbiter, one component of the 2016 ExoMars mission.  Image via ESA

Artist’s concept the Trace Gas and Data Relay Orbiter, one component of the 2016 ExoMars mission. Image via ESA

ESA’s ExoMars consists of two separate missions to investigate Mars. The first, set to launch in January 2016, consists of an orbiter and lander. The lander is called Schiaparelli. The second mission, scheduled for 2018, will deliver a European rover and a Russian surface platform to Mars’ surface. Both missions are aimed at the search for evidence of methane and other indicators of active biological activity on Mars.

What is the speed of thought?

Just how quickly are those thoughts bouncing around in there? Image credit: shutterstock

Just how quickly are those thoughts bouncing around in there? Image credit: shutterstock

It feels instantaneous, but how long does it really take to think a thought?

Titan’s strange lakes may be sinkholes

Radar images from NASA's Cassini spacecraft reveal many lakes on Titan's surface, some filled with liquid, and some appearing as empty depressions. Image via NASA/JPL-Caltech/ASI/USGS.

Radar images from NASA’s Cassini spacecraft reveal many lakes on Titan’s surface, some filled with liquid, and some appearing as empty depressions. Image via NASA/JPL-Caltech/ASI/USGS.

A new study from the astounding Cassini mission suggests that Saturn’s large moon Titan may undergo geological processes similar to those that create sinkholes on Earth. The study might answer the mystery of how Titan – known to be home to seas and lakes filled with liquid hydrocarbons – came to have depressions on its surface into which those liquids can gather.

Earthquakes to blame for Mount Sinabung eruptions?

Landsat satellite image of the eruption at Mount Sinabung on March 6, 2014. Image Credit: NASA.

Landsat satellite image of the eruption at Mount Sinabung on March 6, 2014. Image Credit: NASA.

Mount Sinabung in Indonesia was once considered a dormant volcano, until it erupted for a brief one month period in 2010. Then, on September 15, 2013, it began erupting again and the volcanic activity has continued until today.

Understanding why volcanoes come out of dormancy is no easy task for scientists, but a paper published last year in Solid Earth suggests that some of the recent megathrust earthquakes in Sumatra could be to blame.

How close to finding alien life?

exoplanets-many-habitable-worlds

In recent years, astronomers have become increasingly certain that planets are common in our Milky Way galaxy. And it’s possible that most stars have planets in their habitable zones, an area around stars within which liquid water – and therefore life as we know it – can exist. How many of those worlds are inhabited by simple or complex life forms? And when will we on Earth discover alien life? Follow the links inside to learn more.

Intelligent life in the universe?

Image credit:  JD Hancock

Intelligent life in the universe? Phone home, dammit! Image credit: JD Hancock

If there’s really intelligent life out there, why haven’t they contacted us yet? Here are some possibilities.

A Chinese perspective on summer

Looking for a new perspective on the summer solstice – or some new ways to celebrate? Try these ideas, from Chinese thought.