Around the Solar System

What happened around the solar system last week?  Let's take it from the inside out:

Sun

• A new study just released of the sun from during its recent solar minimum shows that the effects it had on Earth were not what scientists predicted.  

Mercury

• An amateur astronomer, looking at data from NASA's Stereo mission, spotted Mercury's strange comet-like-tail.  The images should help astronomers discover more about the composition of the tail.

Venus

• Turns out the atmosphere at Venus' poles is thinner -- about 60% thinner -- than scientists expected.  The ESA's Venus Express has been diving in and out of the planet's atmosphere to make measurements since it arrived in 2008; it arrived in 2006 and has enough fuel to keep working through 2015.  
• Meanwhile, the lightning on Venus is very much like that on Earth.

Earth

• Keep your eyes peeled for Comet Hartley 2, which will pass just 11 million miles away on October 20.  Look for it high in the northeast at 5th or 6th magnitude.  Next month, the Deep Impact spacecraft will get a much better view when it visits the comet up close and personal.
• If you didn't see any of the pitiful Draconid meteors on Friday night, don't worry: the real show is next year.

Moon

• China launched the Chang'e 2 obiter last weekend (learn how to pronounce it here); it reached the moon Wednesday and will orbit along with the Lunar Reconnaissance Orbiter.  SpaceGizmo has the launch video.
• India hasn't left the game quite yet, with Chandrayaan 2 in the works.  As you remember, Chandrayaan 1 shut down unexpectedly after a brief year in 2009.
• In entirely different news, this Moon is for scratch and sniff purposes only.

Mars

• The Opportunity rover made a nice find, sending back an up-close photo of an iron Mars meteorite.  The rover actually found it on September 16 and spent a few days studying it, before continuing on its way to Endeavour Crater.
• Meanwhile, ESA's Mars Express orbiter photographed this amazing canyon, Melas Chasma, sitting 5.6 miles below the nearby plateau and 3.1 miles lower than Mars' average surface.
• And NASA's Mars Reconnaissance Orbiter revealed that the planet may have once had icebergs.
• NASA got the green light this week for a brand new Mars mission: MAVEN.  The Mars Atmosphere and Volatile Evolution mission will try to determine what happened to the planet's once thick atmosphere.

Jupiter

• Scientists have been simulating conditions on Europa, and may be close to understanding the chemical reactions that happen on the Jovian moon.

Saturn

Water plumes on Enceladus. Credit: NASA/JPL/Space Science Institute.

• The meeting of the American Astronomical Society's Division for Planetary Science has all the news for Saturn this week.  Scientists have performed lab experiments showing that Titan is indeed a contender for extraterrestrial life.  
• Another possible life-holder, Enceladus, may have carbonated oceans (which would explain the moon's spectacular plumes).  
• And as for Saturn's rings, a new theory says they formed when a large moon hit the planet, while Titan does it's moony tide-thing by creating "ring tsunamis."  

Other 

• The Interstellar Boundary Explorer (IBEX) continues to study the heliosphere, which protects the solar system from intergalactic radiation.  The new map shows the boundary changing at surprising rates, so it may not be protecting us from inbound charged particles as much as, well, we'd like.
• Naturally many eyes are focused on asteroids these days, including the Hubble, which imaged Vesta in preparation for NASA's Dawn mission next year, and scientists who have discovered that water may be more common on asteroids than originally thought.

Tags: os99, solar-system, jupiter, mars, saturn