NASA's twin GRAIL probes arrived at the moon on Dec. 31 and Jan. 1 for a cornerstone mission to map the interior of the moon.
"The moon is the nearest and most accessible rocky planetary body that preserves a surface dating back from the time just after the planets formed,” said the lead researcher Maria Zuber, with the Massachusetts Institute of Technology. “Yet we’ve studied other planets more comprehensively. We actually know more about Mars that’s 100 million miles away than we do about the moon."
One of the biggest unsolved mysteries is why the far side of the moon, pictured here by NASA’s Lunar Reconnaissance Orbiter, looks so different from the side that faces Earth.
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Only a tiny fraction of the robotic probes dispatched to study the solar system have gone to Venus, but scientists interested in the planet closest to Earth will have a little relief from their spacecraft-envy in June.
Venus will pass in front of the sun, relative to Earth’s line of sight, the last transit until December 2117. The last one, pictured here, was in 2004 and didn’t draw much attention from scientists.
This time, a barrage of studies are planned, including a look at Venus’ atmosphere as a way to test techniques for studying atmospheres of planets beyond the solar system.
Mission to Mars
NASA opens a new chapter in an ongoing quest to learn if our neighbor planet Mars ever hosted life with the arrival of the Mars Science Laboratory in August.
The robotic rover, nicknamed Curiosity, is due to touch down in a 96-mile-wide basin known as Gale Crater, which sports a distinctive 3-mile high mountain of what looks to be layers of sediments, the remains, perhaps, of an ancient lakebed.
The goal of the mission, which is scheduled to last two years, is to assess if Gale Crater was ever suitable for life. It’s NASA’s first astrobiology mission to Mars since the 1970s-era Viking probes. This view of Gale Crater is looking toward the southwest, with the crater’s central peak in the background on the left.
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A Season on Saturn
Now in its extended, extended mission NASA’s Cassini science probe will continue to chip away at the secrets of Saturn and its eclectic collection of moons.
The follow-on Cassini Solstice Mission, which runs through September 2017, is named for Saturn’s summer solstice, which occurs in May 2017.
Cassini arrived at Saturn in 2004 just after the planet's northern winter solstice, so the extension will allow scientists for the first time to study seasonal changes and other long-term weather systems on the planet and several of its moons.
After a year circling the 330-mile asteroid Vesta, NASA’s Dawn spacecraft will set sail in July for the only larger body in the Main Asteroid Belt, the dwarf planet Ceres.
In doing so, the electric-powered spacecraft, which moves by expelling ionized gas, becomes the first probe to orbit more than one body in the solar system.
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ASA’s MESSENGER mission at Mercury was due to end in March, but scientists won a year’s extension to keep the spacecraft operating. It’s the only one to have ever been put into orbit around the solar system’s innermost planet. The probe is measuring Mercury’s thin atmosphere, mapping its surface and monitoring magnetic fields.
Among the questions scientists would like to answer is how the little planet came to have such a massive heart of iron. In this stereographic projection, Mercury’s south pole appears in the center.
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