Physics

Let’s welcome the new season this week by enjoying time outside to look up at our beautiful stars.

Mercury, which had been in our morning sky, is now slowly coming into the evening.  However, it is too close to the Sun to be able to be easily located.  Mars, also, is almost too difficult to be found, as it is setting just a little after 8:00 P.M. this week.  

We do have Saturn with us all evening, as it rises just about 7:00 P.M.

In the mornings we still have our two brightest planets, Venus, which rises within Leo, the Lion, and Jupiter, rising at 1:00 A.M., easily located in Gemini, the Twins.

The morning of the 16th, notice the waning crescent Moon join up with the heads of Gemini, the stars Castor and Pollux.  On the 19th, it will be in a line with Venus and Leo’s heart, the star Regulus. This can be seen together with the naked eye, but will appear beautifully in a low power telescope.  The Moon becomes New on the 21st, meaning it will then become a very nice waxing crescent in our evening sky.

On the 16th, our Sun will move from Leo, the Lion, to Virgo, the Handmaiden, where it will stay for its longest time within a constellation, over 44 days.  During this time, on the 22nd, it will be situated exactly on the celestial equator - our equator extended into the sky - signaling the start of the season of fall at 2:19 P.M.  However, even though this date is called the equinox, because of our atmosphere, the actual 12 hours of daylight/12 hours of nighttime date will be three days later, on the 25th.

And, yes, please keep watching the constellation Corona Borealis, as we’re still waiting for its star T to brighten to equal that of our North Star, Polaris.  

Before leaving the tiny constellation Lyra, the Harp, we should take a minute to admire its brightest star, Vega, the fifth brightest in our night sky.  Vega is relatively close to us, only 25 light years away, and it appears to be surrounded by a dust disk, comparable to our solar system’s Kuiper belt.  Vega was the first star after our Sun to be photographed, using a daguerreotype, on July 17, 1850 by astronomers at the Harvard College Observatory.  Of major interest is that Vega, about 12,000 years ago, was the closest star to our due north, because of our slightly shifting motion called precession, and it will return to this position in about 12,000 more years.  

We always hear about the first seven astronauts chosen by NASA, but they were fairly quickly followed by the next set, which soon became referred to as the New Nine: Neil Armstrong, Frank Borman, Pete Conrad, Jim Lovell, James McDivitt, Elliot See, Tom Stafford, Ed While, and John Young. More than 200 candidates tried for these positions, but these nine were the group introduced by Dr. Robert Gilruth, Director of the Manned Spacecraft Center, and Stuart Clarke, MSC’s Director of Personnel, both of whom took the stage with the new astronauts to introduce them to members of the press on September 17, 1962.

During John Kennedy’s presidency, the Space Race, and the U.S.’s determination to win, had been pushed, especially with Kennedy’s declaration to land on the Moon by the end of the 1960’s.  But, for many, the cost had been thought to be prohibitive, so on September 20, 1963, the president instead made a call to the Soviet Union for a joint lunar mission.  Soviet Foreign Minister Andrei Gromyko applauded Kennedy’s idea, but at that time refused to commit his nation.  Unfortunately, just two months later, Kennedy was assassinated, new president Lyndon Johnson squashed the idea, and the U.S went on to work independently, reaching the Moon, just as Kennedy had hoped, by the end of the decade.

Everyone loves a good family picture, and on September 18, 1977, the Voyager 1 spacecraft took the very first image of Earth and our Moon in a single frame.  Taken from a distance of 7.25 million miles, it showed both bodies in beautiful crescent phases. When this was taken, Voyager was situated above Mt. Everest, and focused on eastern Asia, the western Pacific Ocean, and the Arctic.  Also, because Earth is so much brighter than the Moon, our neighbor had to be brightened by a factor of three to create such a magnificent image.

Launched in 1989, three years after its intended flight (because of the Challenger disaster), Galileo was considered a game changer with respect to the outer solar system.  It was the first to orbit an outer planet, the first to send a probe into an outer planet, the first to image asteroids (Gaspra and Ida), and the first to actually watch a comet (Shoemaker-Levy 9) crash into another body.  When its mission was over, rather than continue to have it just orbit around Jupiter, it was felt there could be a possibility - although miniscule -  that it could crash into the water world Europa, NASA decided to just have Galileo follow its probe into the planet.  After over 2.8 billion miles traveling around Jupiter, Galileo impacted the planet on September 21, 2003. 

If you do have any images you’d like to share with us, please respond to this email.  We’d love to share them.  

Francine Jackson,

Staff Astronomer

Ladd Observatory