Our bright little comet didn’t make it yesterday, but its death was marked in spectacular fashion by a coincidental CME or coronal mass ejection from the sun’s eastern hemisphere very near the time of the comet’s perihelion, or in this case, its final end. Too bad no one could see this comet visually because of how close it was to the sun, but thanks to SOHO, we can watch its demise frame by frame. Check it out the action at this link. You’ll want to scroll down to the pictures marked either C2 (narrower, more magnified view of the sun and corona) or C3 (wide field). A good place to start is with the picture labeled 20111001_1330_c3.gif
I like to think that had there been a total solar eclipse yesterday, the view of the brilliant comet so near the sun would have been an unforgettable sight. This actually happened on May 17, 1882 when a team of astronomers gathered in Egypt to observe and photograph a total eclipse of the sun. During the middle of totality observers noted a “luminous streak” near the sun about the brightness of the corona. There were no coronagraphs in those days, and no one was expecting a comet, so it came as a surprise. One observer noted that the nucleus or central brightening inside the comet’s coma was sharply defined and the tail curved. Read more about Comet Tewfik HERE.
Right around the time of the comet’s impact or vaporization by the sun, a large coronal mass ejection (CME) erupted from the left or eastern side of the sun. CMEs are huge bubbles of gas threaded with bits and pieces of the sun’s magnetic field often associated with eruptions of solar flares. If directed toward Earth – and this one wasn’t – CMEs can affect radio communications, damage sensitive satellite electronic components, kick-start an awesome display of northern lights or overload unprotected power grids causing blackouts.
What’s curious is the timing. Half a dozen CMEs can happen every day, so it’s most likely a coincidence that this one occurred at nearly the same time as the comet’s destruction. After all, the comet was somewhere in the range of 100 feet across while the sun is 864,000 miles in diameter – too much even for a replay of David and Goliath. Since fragments of this group of Kreutz comets rain down on the sun regularly without a CME to show for their sacrifice, it’s hard to assert a connection, yet astronomers have observed more than a few coincidental pairings. Perhaps future studies may show a relationship.
Let’s cool things down a notch and take a look at the thick crescent moon this evening. It will hang low in the southern sky along the Scorpius-Sagittarius border. The dark patches you’ll see are called lunar “seas” or “maria” (MAH-ree-uh) in Latin. Can you spot all four with your naked eye? If so, your vision is excellent. If not, binoculars will show them plainly. The seas are vast plains of solidified lavas that oozed and bubbled their way to the surface filling the large basins left by earlier asteroid impacts. The surrounding white-toned areas are called the lunar highlands and are the remainder of the moon’s original crust, now saturated with impact craters from bombardments four billion years ago.