What's Up in the Solar System in September 2012

Welcome to our monthly roundup of the activities of our intrepid robotic explorers! And boy, has it been an active time.

Curiosity has begun roving Mars, and Opportunity's not wasting any time either. The big rover is on the way to Glenelg; the small one is on the inner rim of Endeavour crater, checking out an awesome-looking outcrop of sedimentary rock.

Dawn has just departed Vesta and begun the more than two-year cruise to Ceres. Juno is in the middle of a big deep-space maneuver, setting up next year's Earth flyby. GRAIL has begun its first mission extension, and MESSENGER is planning a second.

Venus Express, Lunar Reconnaissance Orbiter, ARTEMIS, Odyssey, Mars Express, Mars Reconnaissance Orbiter, and Cassini are carrying on with their orbital missions. And New Horizons, Deep Impact, Akatsuki, Rosetta, ICE, and Voyager 1 and 2 are traveling onward. No one is sure whether IKAROS belongs in this list or not -- contact has not been made for nine months.

Now let's see what everyone's up to!

At the inner planets:

Last month NASA's MESSENGER mission celebrated the eigth anniversary of their launch. The mission is now about halfway through its first extended mission, and plans are afoot to extend the mission to a third year of operations. As always, check the daily image gallery for cool pictures; I like this one of "an especially unusual feature on Mercury's surface," a conical structure that could be a pyroclastic vent.

ESA's Venus Express orbiter continues to circle Venus, Earth's cloudy neighbor. After a hiatus, the mission has resumed the posting of mission status updates. The most recent covers the mission through April and discusses the restrictions of operation during quadrature (when the angle from the Sun to Venus to Earth is near 90 degrees) and the fun of doing observations from Venus eclipse (when Venus' shade provides temporary relief from the Sun).

Yesterday Ebb and Flow, the twin spacecraft of NASA's GRAIL mission, powered on their Lunar Gravity Ranging System to begin their extended mission. They are zooming over the lunar surface at an average altitude of only 23 kilometers; their orbit will occasionally take them within only eight kilometers of some of the Moon's highest peaks. Yikes! The extended mission will last until December 3.

NASA's ARTEMIS spacecraft are presumably still orbiting the Moon. They were sent into lunar orbit in 2011 to study the Moon's magnetic field, and should last for at least seven years.

China's Chang'E 2 spacecraft left the Sun-Earth L2 point sometime in April for asteroid 4179 Toutatis, and amateur astronomers have recently confirmed that it appears to be on track for a mid-December flyby. China also recently announced that Chang'E 3 will launch in 2013, and include a rover.

NASA's Lunar Reconnaissance Orbiter continues to collect high-resolution imagery of the lunar surface. One recent cool image from their captioned gallery is this one of debris channels within a small crater called Alpetragius B.

Out at Mars:

This is the first time NASA's Curiosity rover has made an appearance in my roundup! Like Opportunity, Curiosity is just a bit south of the equator, so is enjoying the lengthening days of the late Martian southern hemisphere winter; the vernal equinox falls on September 29. (It's currently Ls 164.6 of Mars Year 31.) Less than a month into the mission, Curiosity (just beginning sol 26) has completed the commissioning of her remote sensing instruments, and has just begun the 400-meter drive to Glenelg. The amateurs haven't yet settled on a format for Curiosity's route map, but here's the thread where it'll appear once it gets going.

NASA's Mars Exploration Rover Opportunity has had a busy month and has now (at the end of sol 3059) worked halfway down the eastern slope of Cape York, on the rim of Endeavour crater. She blew through the 35-kilometer mark on her odometer and is hot on the heels of some interesting layered rocks that may contain clay minerals. Who will identify clays first -- Opportunity or Curiosity? Stay tuned! Here's the latest update to the route map from Eduardo Tesheiner.

After watching Curiosity's landing, ESA's Mars Express has continued to perform occasional communications experiments with the rover. The mission has been extended through at least 2014, and continues to gather camera and spetral data on Mars.

NASA's Mars Reconnaissance Orbiter is now providing weather information to two missions, Opportunity and Curiosity, and that seems to have kept the MARCI team from updating their website with a new weather report since August 8! At the time, there was storm activity within Valles Marieris and along the edge of the south polar cap, where springtime sun is boiling off the seasonally deposited carbon dioxide ice. The HiRISE camera continues to deliver daily jaw-dropping imagery of Mars' surface.

NASA's Mars Odyssey spacecraft performed like a trooper during Curiosity's landing and has resumed normal activities alternating between listening for Opportunity and Curiosity data and continuing to map Mars with THEMIS. Here's a really cool recent photo of lava channels on the flank of Ascraeus Mons.

In the Asteroid Belt:

In a few days, NASA's Dawn spacecraft will officially depart asteroid Vesta, although it's of course been receding from the asteroid for a couple of months now. It is on track to arrive at Ceres early 2015. This is the last time Dawn will appear in my "active" section of this report; next month, it'll drop down to the "cruise" section.

Mighty Saturn:

The NASA-ESA-ASI Cassini Saturn orbiter is currently on Rev 171, which lasts through September 13 and takes the orbiter up to 32 degrees above Saturn's ring plane. A 956-kilometer Titan flyby during Rev 172, on September 26, will raise the angle even higher, to 39 degrees. (Next May, the inclination will peak at 62 degrees.) As with previous months, the science focus is on Saturn and Titan's atmospheres and Saturn's rings. To see what Cassini's doing when, check out my long and detailed page on Cassini's tour of the Saturn system, and look to the Looking Ahead page for more detailed information.

Cruising along:

NASA's New Horizons spacecraft has 8.36 AU to go to reach Pluto, and 1046 days until closest approach on Juy 14, 2015. If you'd like to help in the selection of New Horizons' Kuiper belt target, head over to Cosmoquest's Ice Investigators website.

NASA's Juno spacecraft successfully performed its first deep-space maneuver yesterday. That and a second rocket firing on September 4 will set Juno on a course to return to the inner solar system and an August 2013 flyby of Earth. The Earth flyby will give Juno the boost it needs to send it on to its July 2016 Jupiter arrival.

NASA's Deep Impact is in solar orbit, awaiting further instructions for a possible second mission extension. The spacecraft may attempt a flyby of near-Earth object 163249 (2002 GT) in January 2020.

JAXA's Akatsuki is now in solar orbit, on its long cruise to attempt a second Venusian orbital insertion in November 2015.

JAXA's IKAROS has still not been heard from since December 24, 2011. The most recent communication attempt was on August 23; the next is scheduled for September 6.

ESA's Rosetta is now on the final, long leg of its cruise to its target comet. It's been placed into hibernation and will not communicate with Earth again until January 2014. The next object it'll encounter will be its goal, comet 67/P Churyumov-Gerasimenko; rendezvous is set for May 2014.

The International Cometary Explorer remains on course for a return visit to Earth in 2014. When it comes home, ICE can be returned to a Sun-Earth L1 halo orbit, or can use multiple Earth swing-bys to encounter Comet Wirtanen during its near-Earth apparition in December 2018.

Finally, NASA's Voyager 1 and 2 spacecraft are still going strong. Follow the current position of both using the NASAVoyager2 twitter feed (this is not an official NASA account, but it's the one with the most information).