The voyage continues…


Space­craft Voy­ager 1 has officially entered inter­stel­lar space, although exact­ly when it left the helios­phere is still up for debate.m“This is the first man­made object that has left our home—our bub­ble—ever,” says Merav Opher, as­so­ciate pro­fes­sor of astron­o­my at Boston Uni­ver­si­ty and a guest inves­ti­ga­tor on NASA’s Voy­ager team. “Voy­ager is like our scout, telling us what lies beyond our home.”

NASA’s recent announce­ment, based on a new study pub­lished in the jour­nal Sci­ence, fol­lows a debate among some astronomers as to when or even whether the tran­sit beyond the heliopause had occurred. The Sci­ence study places the tran­sit as com­plet­ed on August 25, 2012.

One AU is the dis­tance from the sun to the Earth, which is about 93 mil­lion miles or 150 mil­lion kilo­me­ters. Nep­tune, the most dis­tant plan­et from the sun, is about 30 AU. NASA’s Voy­ager 1, humankind’s most dis­tant space­craft, is around 125 AU. It will take about 300 years for Voy­ager 1 to reach the inner edge of the Oort Cloud and pos­si­bly about 30,000 years to fly beyond it.
dif­fer­ent from the solar mag­net­ic field inside.

One of features of voyager is this golden disk, with a map of how to get to earth, pictures of mankind, and sounds of humanity. Sort of like throwing a note in a bottle out to sea- I wonder if anyone will ever read it, and if we’ll still be around.


16 light hours away, and going strong

Here is the modern ‘pale blue dot’ as taken by the Cassini spacecraft recently.

Pretty impressive that we can even make out the Earth in an image like this. The original ‘pale blue dot’ was part of an even more impressive mission, Voyager.

Voyager is now over 16 light hours from Earth – that is, it takes 16 hours for the signal from voyager to make it back to Earth. Last week one of the instrument team members came into my office and showed me data that had just arrived in. This data showed wild variations in the magnetic field, systematic of voyager leaving the Sun’s influence and moving into the no man’s land of space. It was amazing to see this first hand. The full story is on NPR, including clips from the famous golden record. Have a listen. 10 years from now there will be insufficient power to keep transmitting the signal back to Earth, but voyager will keep going. Forever a testament to Man’s ingenuity.

Where does the solar system end?



It has to end somewhere. Scientifically the solar system has more than one end point. More correctly the sun has more than one end point. The sun gives off a constant steam of particles. At earth we are inside this stream, so even here we are still in the sun. The latest new from the voyager mission is has now reached a new boundary, 11 billion miles from earth. Eventually the stream of particles from the sun hits interstellar space and slows down. Other changes, in the magnetic field strength and direction should also happen. Voyager will keep going and going, so it will be become the first man made object to leave the Sun. The big question is, with only a few dozen years of battery left, will we know when it does so?